CORRELATION OF QUALITY OF ZIRCONIUM CROWNS, ADHERENCE TO PREP-GUIDE, AND EFFECTIVENESS OF DENTIST-TECHNICIAN COMMUNICATION: QUANTITATIVE CORRELATIONAL RESEARCH
by
Copyright 2019
A Dissertation Presented in Partial Fulfillment
of the Requirements for the Degree
Doctor of Business Administration
The Dissertation Committee for …… certifies approval of the following dissertation:
DISSERTATION
Committee:
, Committee Member
…………………., Committee Member
_________________________
_________________________
_________________________
_________________________
, PhD
Vice Provost, School of Advanced Studies
University of Phoenix
Date Approved: ___________
ABSTRACT
Start it here
DEDICATION
Start it from here
ACKNOWLEDGMENTS
Start it here
TABLE OF CONTENTS
Contents Page
List of Tables 24
List of Figures 25
Preface ix
Chapter 1: Title i
Introduction 1
Background of the Problem 4
Problem Statement 4
Purpose of the Study 6
Population and Sample 8
Significance of the Study 9
Nature of the Study 10
Research Questions/ Hypothesis 12
Theoretical Framework 16
Definition of Terms 17
Assumptions, Scope and Delimitations 17
Chapter Summary 19
Chapter 2: Title 21
Title Searches and Documentation 12
Communication and Quality Issues in Dental offices 12
Communication Between Dentists and ……………………25
History of Total Quality Management TQM, 30
Application of Six Sigma Tools 31
Application of LQMS 32
Current DMAIC Approach to Quality Improvement 16
Conceptual Framework Literature 34
Methodology Literature 34
Research Design Literature 35
Conclusions…. 37
Chapter Summary…. 38
References 40
Appendix A: Questinainre 47
Appendix B: Prep Guide 48
LIST OF TABLES
Table 1: Conceptual framework 7
Table 2: List of Dentists in Texas and Houston 2018 9
Table 3: Literature Keywords and the Resources …………………………………23
LIST OF FIGURES
Figure 1: Theoretical Framework 16
Figure 2: Title x
OTHER LISTS
Start here
PREFACE
[start section text here]
Chapter 1
Introduction
Dental technicians deal with quality issues due to the technological changes and ability to communicate with the team members and dentists. The technicians need to communicate with the dentists to produce desired products (Alshiddi, 2014). Communication in dental field is a challenging task because dentists work with a group of employees, including dental assistants, dental hygienist, and front desk staff (Alshiddi, 2014). Meanwhile, dental laboratory staffed with multiple technicians with different skills such as delivery staff, technical advisors, marketing, and human resources team. Communication between team members within the dental laboratory is a challenging task because communication must be done continuously and effectively.
Communication in dental business is an important component of business because the dental treatment requires teamwork. Dentists and the staff in the office must communicate constantly to provide a treatment. Dental offices work not only with the team in the office, but also with team in the dental laboratory to provide prosthetic services (Aboras, Muchtar, Azhari, & Yahaya, 2014). Dentists and technician must communicate in a daily basis if they want to improve the customer satisfaction and relationship that results in successful practices (Alshiddi, 2014). Quality issues become more problematic as dentist and technician fail to communicate which impacts the dental business negatively (Alshiddi, 2014). Lack of communication may be associated with quality issues, which are costly and time-consuming; thus, leading to customers’ dissatisfaction (Aboras et al., 2014).
Similarly, a manager in the dental laboratory must communicate with the staff to ensure that everyone has enough information to complete the task accordingly to the dentist’s written order. The communication occurs verbally and non-verbally through the emailing, written prescription, digital files, and face-to-face (Alshiddi, 2014). In this study, the researcher focuses on the only written communication between the technician and the dentist. Previous studies focused on the technicians’ abilities to follow the written guidelines provided by the dentists (Alshiddi, 2014). The researcher focuses on the dentists’ ability to follow up the laboratory’s prep-guide that presented in figure 1 (Bin-Shuwaish, 2017). Having a standard for the dentist helps to reduce the communication problems at the dental offices by clarifying the quality expectation from the dentists. The communication process in the dental laboratory occurs verbally between technicians and nonverbally between technicians and dentists. Having a written guideline helps to reduce the problem and improves the quality of communication between the dental office and the laboratory that lead to quality improvement. The researcher collects data from the dentists that request for zirconium crowns that require CAD/CAM procedure (computer-aided design/computer-aided manufacture) (Aboras et al., 2014). Creating high-quality dental products requires continuous and effective communication between the dental technicians and the dentists because information flows between dentist and technicians simultaneously. Reliable communication between dentist and technician correlated to the quality of prosthesis, satisfied clinicians, comfortable, professional relationship, and ultimately, successful practices in dental offices (Alshiddi, 2014).
There are three types of communication within the dental laboratory and dental offices, including Web Content Management System (WCMS), paper-based, and face-to-face communication (Alshiddi, 2014). The researcher in this study focuses on the paper-based communication and dentist compliance with specific prep guide that provided by the manufacturer of the CAD/CAM system. Figure 1 in Appendix B shows the example of the prep-guide that dentists use to prepare the tooth accordingly to reduce the natural tooth to comply with the CAD/CAM system (Prep Guide, 2019). Researcher send the questionnaire which is the instrument to the dentists that work with a dental laboratory (Crown World Dental Laboratory) for collecting data from dentists about their expert opinion about the quality of zirconium product. The prep-guide is the communication instrument that informs the dentist about the technicians’ expectations about the quality of dentist work. The researcher uses the independent variables, which is the prep-guide; and dependent variables listed in the questionnaire. ZrO2 restorations called zirconia (alloys like porcelain) possess high mechanical properties, but ZrO2-based restorations are subject to defects such as fracture, shade issues, and bonding to the abutments (Aboras et al., 2014). In summary, the researcher aims to find correlation strength between the independent variable (using the prep-guide) and the dependent variables (quality issues) listed in the questionnaire. Previous studies focused on communication between the dentist and the technicians through the dentists’ written structure, but this study focuses on the communication between technician and dentists through the prep-guide (Alshiddi, 2014).
Background of the Problem
Communicating continuously between dentist and technician leads to customer satisfaction and a better relationship that results in successful practices (Alshiddi, 2014). Having a broken communication between dentists and dental technician creates an opposite result that causes uncomfortable situation for the dentist and technicians (Alshiddi, 2014). Lack of communication between dentist and technician increases the production of the defected prosthesis (Alshiddi, 2014). Making a mistake in dental laboratories is a costly and time-consuming that leads to redoing the zirconium crowns and causing customers dissatisfaction (Aboras et al., 2014). Dentists become upset and uncomfortable with the defected works because of the cost of the chair-time and customer discomfort that may even lead to a lawsuit. Dentists blame the laboratories for not following the written instruction and laboratories blame the dentists for not following the prep-guide provided for the dentists. The problem becomes more complicated when dentists use unexperienced dental assistance to complete the process or using cheap material that reduces the accuracy of the final products.
Conversely, dental laboratories use unexperienced dental technicians to reduce the cost of operation in which leads to quality issues in dental laboratories. The problems escalate from miscommunication between the dentists and the dental technicians, but providing clear written structure helps to improve the quality of work in dental offices. The researcher aims to give insight on the relationship between quality and communication that impacts the customers’ satisfaction by focusing on the problem that comes from dentists because of not following the prep-guide (written communication) presented in figure1 (Prep Guide, 2019).
Problem Statement
The problem of the study is the unknown relationships between the efficiency of technician-dentist communication, adherence to prep-guide, and the different quality indicators of zirconium crowns. Poor quality of Zirconium crowns results in customer dissatisfaction (Martín‐Ares et al., 2016). Quality issues and customer dissatisfaction in dental business are the general issues that are correlated to the poor communication between the dentist and the technicians, and vice versa (Aboras et al., 2014). Production of a crown for a patient is a costly process that ultimately, the patient must pay for the operation. Dental offices and laboratories could reduce the cost of service by working together to mitigate procedural problems. Detecting the defected products in the early stage saves money for both the dental office and the dental laboratories (Schneebeli et al., 2017). The common reasons for failure in quality standards for crowns include discoloration, open-margins, fractures, and imprecise impressions (Moccelini et al., 2018; Wang, Wang, & Qin, 2017). Defected products cause lower profitability, a higher rate of capital cost, and lower brand image. Dentists are the ones that notice the flaws, but correction and remakes of the same crown cost time and money.
Two of the main factors considered for ensuring quality of zirconium crowns are ineffective adherence to the prep-guide and efficient communication between technicians and dentists (Apsari, 2017; Li, Bai, Wang, & Sun, 2018). Therefore, the quality problems related to zirconium crowns are linked to dental offices rather than dental laboratories because of not following the prep-guide, transferring information from the mouth to the cast (model-work) is a challenging task that depends on the dentist and his/her team ability to provide an accurate impression. A dentist should consider prep-guide for every single case; otherwise the treatment may fail because of dentist’s careless prep-work (Li et al., 2018). To further understand the relationship between technician-dentist communication, adherence to prep-guide, and quality of zirconium crowns, there is a need for a quantitative correlational study between efficiency of technician-dentist communication, adherence to prep-guide, and the different quality indicators of zirconium crowns.
Purpose of the Study
The purpose of this quantitative correlational study is to identify the significance of the relationships between the efficiency of technician-dentist communication, adherence to prep-guide, and the different quality indicators of zirconium crowns. The different quality indicators of zirconium crowns include overall quality, seating time, fitness, occlusion, contacts, contour, shade, anatomy, emergence profile, and margin. Based on the purpose of this study, the independent variables are efficiency of technician-dentist communication, and adherence to prep-guide. The dependent variables are the quality indicators of zirconium crowns. The questionnaire in Appendix A is the instrument for collecting data from dentists about their experiences about the quality of work. The goal is to provide insights to the dentists and technicians about the importance of the communication between staff and offices that helps the dental laboratories and dental offices to offer high-quality service and products to the customers. The researcher aims to evaluate quality issues by looking at the relationship between dentists that use the prep-guide and the ones that decide not to use the prep-guide. Table 1 and Table 2 show the dependent variables and independent variable.
Table 1
Definitions of Quality Indicators of Zirconium as Dependent Variables
Dependent variables Definition
Overall quality Overall quality determines the quality if the quality of crowns is acceptable, excellent, or unacceptable (Appendix A).
Seating time Seating time is the time that dentists spend to fit the crown in the mouth (Appendix A)
Rx followed Rx is the written structure (paper commination) that explains the dentist’s expectations (prescription) (Appendix A)
Fit Adapting the prosthetic edge to the abutment which is
the (prepped tooth) (Appendix A)
Occlusion Relationship between upper and lower jaws (Appendix A)
Contacts Contacts surface between adjacent teeth (Appendix A)
Contour Overall shape of the crown (Appendix A)
Shade Color of the crown that matches the natural tooth (Appendix A)
Anatomy Detailed feature of natural tooth (Appendix A)
Emergence profile Blending the crown from the side with the rest of the crowns
Margin Edge of the prosthesis crown (Appendix A)
Due date Appointment date that patient comes back to dental office
(Appendix A)
Table 2
Definitions of Independent Variables
Predictor variables Definition
Adherence to Prep-Guide A communication and training tool for the dentist to
prepare the tooth for the crown (Appendix A)
Effectiveness of Dentist-Technician Communication The level of proper understanding between technicians and dentists (Appendix A)
Population and Sample
The population of the study includes dentists in Houston, Texas. In 2018, the bureau of labor reported 8,110 active dentists in Texas, wherein 2,200 are in the Houston area, which comprise the target population of this study (Occupational employment and wages, May 2018). Table 3 shows the number of dentists in Texas and Houston reported by the United States Department of Labor (Occupational employment and wages, May 2018).
Samples will be obtained from the target population. The sample that will be chosen for this study is composed of dentists with dental offices in Houston Texas that work with the Crown World dental laboratories. Dentists in Houston area use the Crown World dental laboratory to order Zirconium crowns for the patients that need treatment for the decayed tooth. The sample was defined based on the requirements of addressing the purpose of the study.
Purposive sampling is a non-probability method to collect data from the sample when the resources are limited, so purposive method preferred to random sampling because participants are limited for this study (Etikan, Musa, & Alkassim, 2016). The purposive sampling is suitable for the purpose of the study because dentists that willing to follow the laboratory’s prep-guide is limited to the ones that work with the Crown World Dental laboratory.
To begin recruitment, the researcher will request permission from a dental organization with dental practice owners as members. The researcher will advertise the research with the organizational members by providing posters and flyers in the office of the organization. Interested members would be asked to contact the researcher to receive and sign an informed consent form. The informed consent form contains the details of the study purpose, intent for data collection, scope of participation, possible risks involved, and other rights and responsibilities of the participants of the study. The researcher will send the copies of the consent forms to interest participants. If the participant agrees with the contents of the consent form, he or she must sign the form and mail the signed copy to the researcher.
The sampling size that researcher aims to send the request form limited to about 150 dentists, so the sampling limited to the ones that agree to participate in the study by using the prep-guide. The goal is to assign each dentist to answer the survey. Using G*Power statistical software suggested that 134 participants based on a power of 0.95, the effect size of (0.30), and (α) error rate of (0.05). A two-tailed test was performed. Based on the rule of thumb, a power of 80% is the commonly used and accepted value for most studies (Cohen, 1988). However, for this study, a higher power was chosen because of the total population is 2,200. Moreover, a medium effect size of 0.30 will be used for this study, based on common practices for different quantitative power analysis performed to determine sample sizes (Gignac & Szodorai, 2016; Wilkinson, Whittington, Perry, & Eames, 2017). The level of significance is usually set at an alpha equal to a 5% level of significance, the typical standard for statistical significance. Figure 2 shows the result from G*Power software.
Table 3
List of Dentists in Texas and Houston 2018
Dental Specialties Number of Dentists in Texas
General dentists (Texas) 8,110
General dentists (Houston) 2,200
Oral and Maxillofacial Surgeons 460
Orthodontists 610
Figure 2. G*Power Analysis for sample size
Significance of the Study
The study could potentially benefit two sectors: dental industry leaders (e.g., dentists), and researchers in the academic field. Every single person that needs prosthesis from his/her dentist will benefit from this study because the factors that contribute to the quality of the dental crowns will be identified; thus, processes may be developed to improve the quality. Dentists, as leaders in the dental industry, dentists could benefit from this study. There are 2,200 dentists in Houston, Texas. These dentists may benefit from this study. The findings may be used as basis for additional information about the significance of the relationships between the efficiency of technician-dentist communication, adherence to prep-guide, and the different quality indicators of zirconium crowns. From this study, dentists may have basis for providing better services to their customers. Using written communication tool (prep-guide) may improve the quality of work that gives rise to the customer satisfaction. Using this information, dentists could have a basis for improving zirconium crown quality through prep-guide adherence and communication between technician and dentist. Through this study, the researcher can present empirically based findings that dentists may used for the improvement or development of procedures for improving zirconium crown quality.
The findings of the study may contribute to researchers in the academic field by addressing a literature gap in terms of the relationships between the efficiency of technician-dentist communication, adherence to prep-guide, and the different quality indicators of zirconium crowns. The findings of the study can also be used as basis for the topics and explorations in future research.
Nature of the Study
The nature of the study is an exploratory, quantitative with correlational research design to examine the relationship between quality and communication between dentists and technicians. The research method is quantitative, and the research design is correlational that researcher explains further in this section.
Research Method Appropriateness
A quantitative methodology is used when a researcher uses numerical data and tests hypotheses (Sogunro, 2002). Statistical analysis involved in the research and empirical research that data are in the form or numbers (Sogunro, 2002). The quantitative method is appropriate because the purpose of this quantitative correlational study is to identify the significance of the relationships between the efficiency of technician-dentist communication, adherence to prep-guide, and the different quality indicators of zirconium crowns. The participants are the dentists that participate in the research to provide feedback through the survey for every treatment and examining the association of the responses to the ones with no prep-guide. The researcher uses the data for correlation between the dentists’ compliance of the prep-guide (Appendix B) and quality issues mentioned within the questionnaire (Appendix A). The instrument is the survey with the closed-end questions that used by most of the laboratories to examine the quality of products. Therefore, the quantitative method will help to accomplish the research goals because the study requires passive interaction through the questionnaire, large population, before and after training, and availability of statistical package such as (SPSS) (Sogunro, 2002).
Conversely, qualitative method is not appropriate because researchers use the method to build a holistic picture formed with words (Sogunro, 2002). The qualitative method isn’t the right approach because the researcher cannot have an active interaction with the sample population (Sogunro, 2002). There is no need to have an ongoing observation and interviews, so the qualitative method should not consider for this study (Avgousti, 2013). Also, the qualitative method is appropriate for the ethnography and phenomenology because the purpose of the qualitative studies is to explore peoples’ behavior and interpret social realities (Avgousti, 2013).
Design Appropriateness
Correlational design is appropriate for the study because the purpose of the study is examining the strength of the relationship between the variables including independent variables (predictors) and dependent variables (criterion variables) (Pruitt, 2009). Studying the impact of an independent variable on another one with the correlational studies need no manipulation of variables as required by experimental studies (Pruitt, 2009). The correlational design is not appropriate for the treatment of causality; instead let the researcher directly to measure the variables (Pruitt, 2009). Correlational data must connect to specific distinct time to avoid the biased result, which can cause by the time lag between cause and effect (Pruitt, 2009).
A quasi-experimental design is another alternative for this study that helps to evaluate the cause and effect between the variables (Mark and Reichardt, 2008). Quasi-experimental design involves the comparison of variables linked to the time or different groups of individuals (Mark & Reichardt, 2008). Quasi-experiment and correlational designs can be used with the experimental designs to complement the findings and provide preliminary data for further studies (Mark and Reichardt, 2008). The correlational design preferred over quasi-experimental because the purpose of this quantitative correlational study is to identify the significance of the relationships between the efficiency of technician-dentist communication, adherence to prep-guide, and the different quality indicators of zirconium crowns.
Research Questions
This quantitative correlational study designed by the research question: What are the relationships between the efficiency of technician-dentist communication, adherence to prep-guide, and the different quality indicators of zirconium crowns? The question designed to examine the association between usage of pre-guide by dentists and zirconium quality issues. The three hypotheses that intended to answer the research question are listed below.
Hypothesis
The listed null and alternative hypothesis designed to answer the research question, and the researcher tests the correlation coefficient to examine the correlational strength for each null hypothesis. Further examination will implement by determining the relationship between variables, which may be positive or negative. Also, the Pareto chart will be used to classify the quality issues based on the frequency.
H10: There is no significant relationship between adherence to prep-guide and the overall quality of zirconium crowns.
H1A: There is significant relationship between adherence to prep-guide and the overall quality of zirconium crowns.
H20: There is no significant relationship between efficiency of technician-dentist communication and the overall quality of zirconium crowns.
H2A: There is a significant relationship between prep-guide and the overall quality of zirconium crowns.
H30: There is no significant relationship between adherence to prep-guide and efficiency of technician-dentist communication.
H3A: There is a significant relationship between adherence to prep-guide and efficiency of technician-dentist communication.
Theoretical Framework
The theoretical frameworks that set the foundation of this study is situated cognition theory (Brown, Collins, & Duguid, 1897). Situated cognition is a learning theory that refers to learning from experience and social interactions (Brown et al., 1989). For instance, Brown et al. (1989) believed that learning is a social experience and individuals are able to learn when they interact with others, communicate, problem solve and share knowledge with each other. For example, dentists could learn how to improve quality of zirconium crowns through interaction and communication with technicians.
Definition of Terms
Prep means a tooth that prepped by the dentist for prosthetic treatment.
Remake means redoing the cases because of technical failures.
Crown is fabrication of missing part of any tooth with zirconium materials.
Margin is the border between the prepped tooth and the rest of the tooth toward the root.
CAD/CAM stands for (computer-aided design) and (computer-aided manufacture).
TQM is the total quality management including Six-Sigma, and Define, Measure, Analyze, Improve, and Control (DMAIC) that takes total employees’ involvement to approaches to complete the cycle of process management (Jung-Lang, 2008). TQM technique involves activities for quality management, including Plan, Do, Check, Action (PDCA) that builds the concept of continuous improvement daily (Jung-Lang, 2008).
Just in Time (JIT) is the creation of efficiency and reduction of overhead that increases return on investment (ROI), and elimination of the unnecessary work-in-process to ensure a continuous flow of products (Ohno, 1988)
Lean is the philosophy applied to the process of any business to improve productivity and to eliminate non-value activities and reduce the lead-time to deliver products to customers (Johnson, 2015).
Assumptions, Scope and Delimitations
There are four assumptions in the study of the association between communication and quality issues among the dentists and technicians that lead to quality improvement and customer satisfaction. The first assumption is that a significant relationship exists between dentists’ ability to follow the prep-guide and quality improvement. There is an assumption that prep-guide (written-communication) is a great tool to allow the technician to communicate with the dentist, which lead to customer satisfaction. Next, the researcher believes that participants (dentists) provide information about their experiences sincerely to provide data about the quality of zirconium crowns. The researcher assumes that participants are credible and trustworthy, and their information purely helps the study to provide information about the research question. Finally, the researcher believes that the findings may not be generalizable because of purposive sampling and limiting the investigation to the dentists that work with the Crown World Dental laboratory. The questionnaire must send to the dentists that were already working with the company, so the limitation of the sampling may become a barrier for the generalizability of the findings. Conversely, G*Power calculation suggested 134 participants that will be enough to produce generalizable results.
The scope of the research limited to the dental laboratories and dental offices that use CAD/CAM system, and the study is essential for the whole industry because CAD/CAM system dominated the industry. The scope of the study requires dentists with the ability of to providing an acceptable prep, which is time-consuming and costly for the offices. Evaluating the strength of correlation between variables may improve the validity and reliability issues due to external sampling issues. The quality issues vary among the dental office because of the business model and type of services that may impact the dentist’s ability to contribute to the study.
There are general issues that limit the validity and reliability of the instruments, such as participants’ intention. Participants may find themselves uncomfortable to share sensitive information and provide inaccurate information about their experiences. Submitting information about the quality of the products may not represent the larger population or situation that impacts all dental offices. Measuring the correlation strength between the quality of products and each criterion variable may become challenging if participants avoid participating fully before reaching the saturation level.
The study’s delimitation managed by considering only the participants (dentists) that work with the Crown World Dental Laboratory in Houston. The study delimited by using the sample size that suggested by G* Power software (134 participants), in which reduces the rate of type I and type II errors and improves the possibility of generalizability. Research questions limited to closed-end questions that provided through the questionnaire listed in Appendix A. The research question examines the strength of the relationship between usage of prep-guide and quality improvement that recorded int the survey (Appendix A).
Chapter Summary
The purpose of this quantitative correlational study is to identify the significance of the relationships between the efficiency of technician-dentist communication, adherence to prep-guide, and the different quality indicators of zirconium crowns. Dental treatment is a costly procedure because staff in the dental offices and dental laboratories work as a team to provide dental services to their patients including the zirconium crowns. The researcher aims to evaluate the correlational strength between the predictor (usage of prep-guide) and criterion variables (quality issues). Dentists are the target population, and sampling size depends on the availability of the dentists that willing to participate in the study. The research question focuses on the relationship between quality of zirconium crowns and dentists’ compliances of the prep- guide. The scope of the study narrows down to the available dentists that already deal with the quality issues. Dentists should have enough time to finish their work, and not all dentists will be available in the same time, so the researcher needs at least three months to collect the data from enough participants that willing to participate in the study.
The assumption is that participants join the study eventually and provide their unbiased suggestion based on the final products. The researcher uses the closed-end questionnaire to conduct quantitative research that offers correlational insight about the quality issues and the written communication (prep-guide). The researcher focuses on communication issues between the dentists and technicians, which is the research gap and essential for the quality improvement in dental offices. There are three hypotheses for the study. Quantitative methodology and correlational design are appropriate because of the nature of the study that requires statistical analysis. Chapter two begins with the introduction to literature review and articles that provide secondary information about relationship between dentists and technicians, quality issues in dental laboratories, communication in medical field, and quality assurance practices, such as the six sigma, total quality management (TQM), quality improvement, Just in Time (JIT) quality control.
Chapter 2
Literature Review
In this section, the researcher focuses on the literatures that provide information about the quality management and communication between the dental offices and dental laboratories. The literature review consists of the articles such that the dental technicians’ compliances of written structures by the dentist (Alshiddi, 2014). Literatures about the quality management of different products in sectors such as tire and garment company that used lean six-sigma to determine the problems and find solutions for the issues. Subjects about the total quality management (TQM) techniques, such as Six-sigma, are used among managers for the purpose of the quality control (Schmidt, Sousa-Zomer, Andrietta, & Cauchick-Miguel, 2018). DMAIC stands for defining, measuring, analyzing, improving and controlling in which is a methodology to map out the problems and solution for the high rate of the defects in the dental laboratories (Sharma et al., 2018).
The purpose of this quantitative correlational study is to identify the significance of the relationships between the efficiency of technician-dentist communication, adherence to prep-guide, and the different quality indicators of zirconium crowns. The researcher focuses on the previous studies that examined the poor-quality-works in the production lines, such as a tire, wire rod, and garments. The companies used the six-sigma to find solutions to improve the quality of the products in a different sector. The researcher compares the methodology and design of the studies to discover similarity and difference with the undertaken research. The research question addresses the problem related to the dentists’ compliances of the prep-guide and association with the quality issues. Germinal data collected from the University of Phoenix database that associated with total quality management (TQM), quality improvement, and just in time (JIT), quality issues in a dental office, and communication issues in dental and medical offices. The articles are scholarly, and peer-reviewed that provide germinal information about the topic and research purposes.
Title Searches and Documentation
The literature and information obtained from scholarly journals, textbooks, and official websites. The academic and scholarly peer-reviewed publication that related to the TQM in business and communication in dental industry accessed from EBSCOhost, ProQuest. The leading search engine was the Google Scholar and Google website that used to retrieve peer-reviewed literature about the topics during the last ten years. Information about the communication between dental offices and laboratories accessed from the Internet database such as Dissertation and Thesis, ProQuest, and Sage at the University of Phoenix website.
The scholarly document accessed from the University of Phoenix library and google scholars by using keywords including, communication between dentist and technician, quality issues in dental laboratories, quality issues in dental office, communication in medical field, sample size estimation, total quality management (TQM), quality issues with zirconium crowns, Six-Sigma, just in time (JIT), LQMS, SIPOC, MSA, FMEA, Pareto Chart, DPMO, DPU, and PPM. Table 4 shows a summary of the literature that retrieved from the University of Phoenix and the Internet database search engine such as Google Scholars.
Table 4
Literature Keywords and the Resources
Area of the research Peer-reviewed articles/Journals Scholarly books Doctoral Dissertation
Communication 6
Quality management 17 1
Research method and design 3 2
Sample size 1
Teamwork 3
Customer satisfaction 4
Communication Issues among Professionals in the Dental Field
Bin-Shuwaish (2017) suggested that compliances with the dentists’ written guidelines help the quality of work to improve and reduces the defect in dental laboratories. The findings of the study indicated that the research needs more longitudinal analysis and collecting more data from more extensive range dental laboratories (Bin-Shuwaish, 2017). The study provided insight into the regular communication between the dentists and the dental laboratories, but the conversation just focused on the dental laboratories. The study has a lack of information about the importance of mutual communication between laboratories and dental offices. I consider the importance of dentist’ ability to provide a classic impression that let the technicians to transfers the data from mouth to a cast (model-work). The researcher aims to address the research gap by considering dentists’ compliances of dental laboratories guideline.
Limited research existed about defect rates of zirconium crowns and quality management that promotes using of six-sigma in the organizations that show cause and effects relationships (Schmidt, Sousa-Zomer, Andrietta, & Cauchick-Miguel, 2018). Dental laboratories are not the exception, and another business avoids using the six-sigma to conduct the quality of their production. Studies about the six-sigma cover issues related to customer satisfaction and defect management process and DMAIC process.
Why Dentists Change Laboratories
Dentists work with their labs for three reasons, including quality, excellent communication, and reasonable pricing (Burns, 2013). There is about %49 percent of the dentists that change their laboratory because of communication issues that stop the dentist from building a long-term relationship (Burns, 2013). Dentists are looking for advice from the laboratory regarding the shade, impression-taking techniques, restoration, and material choices (Burns, 2013). Dentists express their concern and switch their lab if there is no solution to the problem (Burns, 2013). The study indicates that communication is an essential factor that creates a long-term relationship or causes dissatisfaction because of poor quality produced by the dentist and the technician. Dentists quiet their labs because of quality issues and studying quality issues that related to the communication between dental laboratory and dentists helps to build a good relationship between team members in the dental offices (Burns, 2013).
Communication Between Dentists and Dental Technicians
Tulbah, Alhamdan, Alqahtani, Alshahrani, Alshaye, (2017) explored issues related to the communication between dentist practitioners and the dental technicians about the authorization and selection of the trays and materials. The study suggested that clear communication is a critical factor that improves the quality of fabricated fixed and removable prosthesis (Tulbah et al., 2017). The researchers contributed a questionnaire among the dental technicians that concerned with the quality of written instruction from dentists (Tulbah et al., 2017). The findings indicated that only half of the written instructions were clear, and the rest needed farther communication between dental technician and the dentist to produce quality-work (Tulbah et al., 2017). The study indicates that communication between dental technicians and dentists is a critical factor for the success of the final products. The communication is essential, but it must happen mutually rather than just dentists provide a written guideline. Having dentists to follow up with the dental laboratory’s’ prep guide helps to improve the quality of the dental products, which is the goal of the researcher in the study.
Overall, the role of quality communication has been widely examined in previous research. In this study, however, only a few studies were included for critical analysis. The researcher included only studies that were published in the last five years (2014-2019). It is also worth noting that Tulbah et al. (2017) is a Saudi Arabian study. Another related study that was published within the last five years is Sudanese as it was conducted at the capital of Sudan, Khartoum. The researcher paid little attention to critically analyze the Sudanese study because the findings were less relevant and contributive to the present study. Particularly, the research explored communication between dentists and dental lab technicians whereby they indicated that the quality of communication was low (Arbab Ali, Khalifa and Nasser Alhajj, 2018). Nevertheless, the authors of the study did not indicate its impact on the quality of dental services.
Furthermore, the findings of Tulbah et al. (2017) and Arbab Ali (2018) were reaffirmed by another Saudi Arabian study that investigated the compliance of dental lab technicians to the written instructions by dentists whereby the findings revealed that commercial labs performed better than government labs (Bin-Shuwaish, 2017). The authors further indicated that this phenomenon explains the quality differences between commercial labs and government labs. Therefore, the theory that was formed from the findings of this study aligns with other theories that have been originated in other studies like that of Tulbah et al. (2017).
Therefore, the main literature gap that could be identified concerning this sub-topic is that there is insufficient literature of prior research examining the various factors that affect the quality of communication between the dentist and dental lab technicians. However, the few studies available have suggested that the quality of communication affects general service quality significantly. From an action research perspective, it is therefore imperative to also examine the various factors that affect the quality of communication to initiate potential solutions to the problem. Nonetheless, there is a general notion that the mode of communication can affect various aspects of quality communication such as timely message delivery and so on. Some of these modes have been highlighted in the previous section of this report. For instance, Parry, Evans and Cameron (2014) discovered that only 15% of dental lab technicians complied with written prosthetic prescriptions by dental students, an indication that handwritten work authorization could be a less effective communication tool in this setting. Therefore, it is also significant to evaluate the effectiveness of various communication means such as handwritten work authorization and website content management system (WCMS).
Communication with the Handwritten Work Authorization vs WCMS
Communication between the dentist and the technician happens through the handwritten work authorization, but digital advancement led to the electronic communication between the dentist and the technician. Alshiddi (2014) explored issues related to communication methods such as web content management system (WCMS) and paper communication methods to improve the communication quality due to the fast Internet connection that allows faster upload and download than usual. The researcher suggested that WCMS helps the dentist to communicate more quickly and effectively with the technician that lead to quality improvement (Alshiddi, 2014). Web content management is available for the dental offices to communicate with the partners, but the privacy issues become a severe problem for the dental offices (Alshiddi, 2014). The author claims that paperless communication saves money and time for the dental offices; thus, eventually becoming mandatory in some countries (Alshiddi, 2014). Considering the paperless communication is a perfect choice for many offices, but the elimination of paper communication may not be possible for every office. Working with the CAD/CAM system provide an opportunity for the dentist and technician to communicate digitally, but communication between the technician and the dentist may become challenging. In a dental laboratory, technicians work together to produce dental products, while communicating with every single technician becomes very challenging. The dentist may request any orders and demand for the desired outcome, but the technician cannot claim for change because the dentist already does the job. Quality of work by dentist impacts the quality of dental products and technician may not be able to request for a change because of costly chair-time in the dental office. Considering the cost of late communication, the technician should communicate in advance with the dentist to reduce the possibility of mistakes in the dental office. Asking the dentist to use the prep-guide is the best way to create a pro-active communication with the dentists that help to reduce the mistakes done in the dental office.
The findings of Alshiddi (2014) were confirmed by another study by Bin-Shuwaish (2017) which investigated the compliance of dental lab technicians to written instructions by dentists. The findings of the study indicated that compliance was considerably determined by many factors including the type of communication between dentists and dental lab technicians. The study discovered that paper-based communication was the least effective among other forms of communication such as web-based, personal, verbal, and photographic. These observations were also reflected by another study by Özyemişci Cebeci (2018) which investigated factors influencing low-quality instructions for removing partial denture design. The author insinuated that paper-based communication is not only expensive but also the least effective among other forms of communication such as telephone call, text messaging, email, and web-based communication. Therefore, low-quality instructions are commonly associated with paper-based communication hence the need to embrace web-based communication than paper-based communication.
Moreover, the issue of paper-based communication has been associated with other aspects of poor communication in the context of dental practice. For example, in their study, Alammari and Albagar (2018) investigated the quality of written communication between senior dentist students and dental lab technicians. The findings of the study indicated that senior dentist students communicate poorly, and this phenomenon was connected to the communication techniques that they learned during their clinical education. Predominantly, the findings indicated that most students learned paper-based communication techniques during their clinical education, and this extended to their poor communication with dental lab technicians. Nevertheless, Gaylor (2016) hinted that a combination of both paper-based and web-based communication techniques in a dental setting improves the overall quality of communication. Though the author did not provide sufficient reasons for this observation, the researcher of the present study connected the phenomenon with improved data privacy, cost, and fast transfer of information. Chiefly, prior studies have indicated that the use of pure web-based communication between dentists and dental lab technicians is cost-effective and timely, but it poses major challenges to data privacy. Also, paper-based communication could be more confidential than web-based communication. Hence, the combination of the two improves the efficiency of communication by observing all aspects (such as cost, timeliness, and data privacy) in a single package. Furthermore, the researcher of the current study supposed that, if the purpose of combining paper-based and web-based communication is to promote data privacy while observing cost and timeliness, then it is also possible to replace paper-based communication from the duo with other more effective forms of communication like text messaging, e-mail, and telephone call. For instance, text messaging can help in observing data privacy because the communication is directly between the sender and the receiver without the involvement of third parties. Since scholars like Özyemişci Cebeci (2018) have observed that these forms of communication are more effective than paper-based communication, then it is recommendable to perform the proposed substitution. Overall, web-based communication is superior to paper-based combination hence the need for minimal utilization of the latter.
The Importance of Developing Communication Skills
Dental hygienists are major team players in dental offices and have to communicate with dentists and the patients. Developing communication skill of the hygienist is correlated to their ability to perceive effective communication, understand barriers, and ability to use personal communication tools (Walker, Jackson, & Maxwell, 2016). The researchers contributed six open-ended questions to two broad classes of the first- and second-year hygienists’ students at Indiana University to collect data about their perception of effective communication, barriers they encountered, and emerging technology (Walker et al., 2016). The gap mentioned in this study linked to the emerging technology that future studies may focus on and find solutions for the communication issues among the team members in the medical field (Walker et al., 2016).
Nevertheless, the findings of Walker et al. (2016) have confirmed that communication in any healthcare setting including dentistry is very challenging. This observation was also avowed by numerous other studies such as Alammari and Albagar (2018) which indicated that the kind of communication taking place between dentists and dental technicians is generally poor in multiple settings. In a study (Waylen, 2017) that investigated the importance of effective communication in dentistry, it was discovered that communication in this setting is challenging because it is both a clinical and complex skill that pertains to direct patient care and constituent skills. Waylen (2017) further observed that effective communication between dentists and dental technicians promotes a good relationship not only between them but also with other team players like hygienists. Effective communications also promote respect between professionals and facilitate improved patient care. Therefore, the researcher of the present study observes that collaborative learning in dentistry would help in alleviating communication problems between dentists and technicians. In this way, dental students will learn both constituent and clinical communication skills in an integrated manner resulting in better results. These observations are consistent with the literature in other healthcare settings such as nursing – for instance, El-Sayed and Ahmed Mousa (2015) discovered that cooperative learning improves the development of communication skills among psychiatric nursing students. Therefore, one of the possible solutions to improving communication between dentists and dental lab technicians is to introduce cooperative or collaborative learning in teaching communication skills among dentistry students. Currently, this is a literature gap hence the need to confirm these observations in the future through the use of empirical means.
Quality of Zirconia
During the recent years, demand for the zirconium crows increased due to the durability and natural-looking results in which CAD/CAM system allows to produce the zirconium products (Meirowitz, Bitterman, Levy, Mijiritsky, & Dolev, 2019). The open- margin is the critical issues that dental offices face and having a defect in the margin is a severe problem (Meirowitz et al., 2019). The researchers examined two available CAD/CAM systems, including CEREC and LAVA, to explore issues related to margin, and there was no significant difference between the two systems. The study of zirconium quality limited to the margins within the two systems and researcher never mentioned about the role of the dentist in quality issues. The problem with this is study is that the researchers assumed that the dentist does not make a mistake, which is not valid in reality. Considering the role of the dentist in quality issues lead my study to examine the relationship between dentist compliances with the dental laboratory requirements through the written communication tools such as prep guide.
In another related study, it was determined that the type of material used in manufacturing monolithic zirconia dental crowns affects the quality of the margins (Schriwer et al., 2017). The study investigated the quality of the margins in six different types of dental zirconia crowns whereby the quality of the margins was assessed by using light microscopy in an ordinal scale. The findings of the study revealed that the quality of margins was statistically different between the six different commercially available crowns. However, unlike Meirowitz et al. (2019) who discovered that production method does not impact on the quality of margins, Schriwer et al. (2017) concluded that production method and the zirconia material used affects the quality of margins. Additionally, this study discovered that there was a statistically significant correlation between fracture load and the quality of margins. This discovery was also confirmed by another study by Skjold, Schriwer and Øilo (2018) which investigated the factors influencing the fracture (survival) of zirconium-based restorations where it was revealed that margin design is one of them. Other factors, in addition to material selection, manufacturing type, and margin design, that have been implied in the literature include balancing tooth size and shape, surface state, tooth contact conditions, residual stresses, and tooth structure (Zhang and Kelly, 2017). Communication plays a major role in ensuring the balancing of these factors to produce the most desired zirconium-based restorations. However, no study has investigated the correlation between the quality of communication and some of these factors, which is a significant literature gap that the present study pursues to fill. Additionally, it was observed that many studies have investigated surface quality of zirconium-based restorations.
Studies that have investigated the surface quality of zirconium-based restorations have implied a connection between surface quality and fracture load. For instance, in their study, Li et al. (2018) discovered that the type of manufacturing affects the quality of the surface of zirconium-based restorations which in turn affects their fracture load. This finding was confirmed by another study by Lameira et al. (2015) which indicated that monolithic and bi-layer zirconium restorations portray different levels of fracture strength. Lameira et al. (2015) exposed the two types of crowns to artificial ageing whereby it was revealed that monolithic crowns have a higher level of fracture strength than bi-layer zirconium restorations. This study concluded that surface finishing and design has an impact on the fracture strength of zirconium crowns. Moreover, monolithic zirconium restorations have different surface designs namely thick-walled and thin walled. In a study, it was discovered that thin-walled crowns are less resistant to fractures than thick-walled crowns (Øilo et al., 2019). Overall, these studies have indicated that there are numerous factors affecting the quality of zirconium-based restorations and proper communication between the dentists and dental lab technicians is crucial in meeting all of them. Studies like Shi et al. (2015) have discovered that the quality of crowns affects patient satisfaction profoundly hence the need for adherence to proper communication. Indeed, in a case report study, it was concluded that proper communication is key to the clinical achievement of high-quality crowns for improved patient satisfaction (Kourtis, Bachlava and Roussou, 2016).
Shade Issues
The shade is another issue that dentist and technician face since patients want natural-looking tooth that matches with the adjacent teeth (Alomari & Chadwick, 2011). Using different shade tab to decide on the shade causes confusion and problem for the technician and the dentist (Alomari & Chadwick, 2011). Vita shade tab is the classic shade tab that dentist use to match with the natural tooth and ask through the written prescription to duplicate the shade, but sometimes dentists use different shade tabs which are different than the one that laboratory uses (Alomari & Chadwick, 2011). Shade tab is a communication tool between the dentist and technician that let the technician take the necessary steps to duplicate the crowns (Alomari & Chadwick, 2011). The study suggested that communication between dentist and technician is essential, and lack of communication impacts the quality of work in dental offices.
Shade issues have been studied extensively in the literature. Since lack of communication affects the quality of work, especially shading issues, it is also imperative to examine some of the issues that are likely to be relevant to the communication aspect. In their study, Ahangari et al. (2015) discovered that different shading techniques namely staining with brush and submerging in coloring liquid have different effects on the value of zirconium crowns. The study particularly discovered that the submerging technique is better than staining with a brush. However, the appropriateness of technique is based on specific customer requirements hence implying that poor communication might result in the use of an inappropriate shading technique.
This observation has also been confirmed by other scholars. For instance, Tulbah et al. (2017) indicated that a dentist should indicate the type of shade needed in the written authorization. However, about 75% of their participants reported that they received a specification of shade type from dentists, which indicates poor utilization of communication to promote patient satisfaction provided that the colour of the shade is a preference of the patient. These findings were also affirmed by Arbab Ali et al. (2018) whereby about 44% of their participants indicated that they did not receive specific shade type to be used. Since Ahangari et al. (2015) indicated that the technique used in shading zirconium crowns affects their quality, Arbab Ali et al. (2018) and Tulbah et al. (2017) confirmed the significance of communication between the dentist and dental technician. The importance of communication in this context was also reiterated by Eakle and Hatrick (2015). However, unlike the other studies, Eakle and Hatrick (2015) indicated why it is significant for dental technicians to help dentists choose the most appropriate shade to prevent unnecessary frustrations related to additional lab fees in case an inappropriate shade is chosen. Therefore, in case there is a statistically significant correlation between the quality of zirconium crowns and communication, the findings of these studies have revealed the mechanism involved. If the correlation is not statistically significant, then it shall be confirmed that the fact that Ahangari et al. (2015) did not imply the role of dentists in their study affected the conclusions of the researcher regarding this subject.
Factors Affecting Dental Quality
Quality in dental offices affects patients’ satisfaction and depends on factors, such as: communication, responsiveness, reliability, waiting time, admission process, satisfaction, and technical competence (Bahadori, Raadabadi, Ravangard, & Baldacchino, 2015). The study of total dental quality management received the least attention among the other professions and fluctuation of quality lead to the dissatisfaction among the dental patient (Bahadori et al., 2015). Responsiveness was one of the major factors that influence to customer satisfaction when a patient needed multiple treatments, but staff unwillingness to provide the best the services led to the wasting patients’ time, money, and energy (Bahadori et al., 2015). Reliability is another essential factor that the researchers mentioned that impacts the customer satisfaction and helps to improve the quality of work by reducing the waiting time and cost of operation (Bahadori et al., 2015). The researchers emphasized the role of poor communication that impacts the quality issues in dental business and causes customers’ dissatisfaction (Bahadori et al., 2015). The study suggested that the quality of work depends on many factors, especially poor communication, are associated to the quality of work in dental offices (Bahadori et al., 2015). The researchers suggested that improving the quality in dental offices requires the attention of staff to every patient’s need responsiveness is the key to improve customer satisfaction (Bahadori et al., 2015).
Bahadori et al. (2015) are one of the few researchers that have investigated the significance of communication between the dentist and other professionals in the dental office and revealed the mechanism of involvement. When the author performed an advanced search strategy on Google Scholar, no other study was retrieved concerning the importance of interprofessional communication in the dental office. However, studies examining interprofessional communication between dentists and other healthcare professionals such as medical doctors, nurses, and pharmacists have been published in the past. For instance, Lutfiyya et al. (2019) investigated the impact of healthcare collaborative practice in various patient outcomes such as satisfaction and cost of care. The findings of the systematic review of the literature discovered that collaborative practice, which is characteristic of interprofessional communication, reduces the cost of care and improves patient satisfaction. This finding insinuated that communication between dentists and dental technicians could improve various patient outcomes in the dental office. Overall, although many scholars like Lutfiyya et al. (2019) advocate that collaborative practice is part of healthcare reform in countries like the United States, many others have also acknowledged that there is limited research in this area. For instance, in their study, Sippli, Rieger and Huettig (2017) indicated that there is limited research on the interprofessional collaboration expectations between dentists and general practitioners. Similarly, the researcher of the present study discovered that there is limited research on how communication between the dentist and the dental technician could influence the quality of zirconium crowns and the overall quality of service delivery at the dental office. Therefore, the current study aims to fill this literature gap by exploiting the correlation between the quality of zirconium crowns, the effectiveness of communication between the dentists and dental technicians, and adherence to prep guide.
Quality Assurance Practices
Total Quality Management in Dental Practices
Dental laboratory managers implement total quality management (TQM) by determining the goal and objectives, control the cost, availability of the documents and instructor in the practice, and determining lack of the standards (Harr, 2001). The TQM in dental business subdivided to three sections of “structural quality” (quality for services, infrastructure, and training), “process quality” (quality of treatment process), and “outcome quality” (quality of the treatment outcome) (Harr, 2001, p.4). The outcome quality is the aim of this study by exploring the correlation between a dentist’s compliance with the prep-guide and the quality issues listed in the questionnaire. The treatment process is vital for the study because dentists must follow the guideline and provide necessary means that a technician can use to produce the zirconium crown.
Additionally, many studies have investigated TQM in various contexts of dental practice with significant implications in the context of communication between the dentist and dental technician. For example, Khoshnevisan et al. (2019) emphasized that interprofessional communication and other professional issues in dental practice could be solved through continuous professional development by means of mentorship. Khoshnevisan et al. (2019) made this recommendation in the context of clinical governance as a prime strategy for continuous improvement through the best standards of dental care. Nevertheless, in their systematic review of the literature, Snowdent et al. (2017) discovered that the application of clinical governance into dental practice is limited in the United Kingdom due to lack of knowledge and confidence by practitioners in its application and evaluation. The study concluded that there is a need to conduct more research in the future to instill confidence in practitioners because clinical governance is a viable framework for improving the quality of care in dental practice as a vital component of TQM. Since communication is one of the determinants of patient satisfaction in any clinical setting, it is imperative to examine its correlation with adherence to prep-guide and quality of zirconium crowns. This observation is reaffirmed by another UK study which discovered that there is a strong connection between TQM and patient satisfaction (Schakaki and Watson, 2017). Therefore, patient satisfaction is the moderating factor in the connection between TQM and interprofessional communication. However, this connection has not been explored in the literature. Thus, future research should also focus on testing this hypothesis because it is a significant gap in the literature that could help in advancing the findings of the present study. Therefore, one of the avenues of implementing TQM to a dental office to enhance communication between the dentist and dental technician among other professionals is introduction of clinical governance. Since it is currently challenging to execute clinical governance into dental practice, it is also prudent to evaluate the history of TQM and other strategies from the outset to lay a firm groundwork for future research.
History of TQM, Six-Sigma, and Just in Time (JIT)
Quality managers use Total Quality Management (TQM) since the 1980s and six-sigma came later as a new tool to improve the quality at workplaces such as GE and Motorola (Schmidt, Sousa-Zomer, Andrietta, & Cauchick-Miguel, 2018). TQM uses part per million defectives (ppm) and yield to measure the rate of defects and assess the quality then react to the problem (Jung-Lang, 2008). TQM used by quality managers through the plan, do check, and action to reduce the rate of the defect (Jung-Lang, 2008). Six-sigma used by quality managers to reduce the frequency of the deficiency by using DMAIC methodology to tackle undesirable activities that cause a defect. For example, quality managers of the factors that make steel wire rods used Six Sigma methodology to improve the quality towards the target of 3.4 failures per million opportunities (DPMO) (Ridwan, Ekawati, and Novitasari, 2018). Just in time is another TQM methodology that reduces the waste in an organization. Toyota used JIT to manage supply, production, and performance for many years in which made the customers happy and satisfied (Danese, Romano, and Bortolotti, 2012). JIT used to reduce the production time and eliminate practices that cost money and produces no value for the customers (Danese et al., 2012). JIT is a useful method to reduce the defect rate of products because managers improve the quality of inventory by lowering the cost of overstock. Managers use JIT by measuring factors such as unit cost of manufacturing, inventory turnover, on-time delivery, and fast delivery (Danese et al., 2012).
Presently, Six Sigma is widely used in various fields of practice including dentistry. However, there is limited research on how the Six Sigma methodology could be used to improve the communication between the dentist and other professionals like dental technicians. However, some studies have implied that the use of Six Sigma could help in improving the overall quality of care in dental settings. For instance, Akifuddin (2015) discovered that the utilization of Six Sigma Methodology helps in a significant reduction of complications of local anesthesia in dental healthcare setups thus demonstrating improved quality of care and patient satisfaction. In other healthcare settings, the Six Sigma methodology has shown remarkable effectiveness in reducing care related costs (Sunder and Kunnath, 2019). It has also been associated with improved handoff communication (Mistry et al., 2019). Overall, the findings of this literature review have revealed that the application of Six Sigma methodology in dentistry is currently limited due to lack of knowledge. However, the findings of the few studies that have been cited have indicated that Six Sigma could be a potential quality management approach in dental settings due to improved communication between professionals, reduction of cost, and ultimate improvement of patient satisfaction.
Nevertheless, the JIT industry is widely used in the manufacturing industry (von Scheel et al., 2015). It could also be used in manufacturing high-quality zirconium crowns. However, when the researcher performed an advanced search on Google Scholar to identify studies that have examined its effectiveness in dentistry, none was retrieved. This observation insinuates limited literature on this topic hence the need for future studies to examine the potential application of JIT in dental care. Overall, TQM is the commonly used approach followed by Six Sigma. JIT has little or no application in the present time. Therefore, it is imperative to examine the communication dimensions related to TQM since it is the most commonly utilized in dental care settings.
Communication Dimension Related of TQM
TQM philosophy focuses on fulfillment of customer requirement for every single time with no exception and improving the quality of work continuously (Serdar Pirtini, 2003). Quality should build in the process of production rather than inspecting the process regularly to ensure that quality meets the customer requirements (Serdar Pirtini, 2003). TQM benefits from communication process by creating two-way communication wherein customer requirement is identified in a systematic way (Serdar Pirtini, 2003). The implementation of TQM in an organization depends on the team able to communicate proactively instead of reactive communication (Serdar Pirtini, 2003). In TQM, communication means interaction for a common goal and sharing encoded knowledge, feeling, and thoughts that promote quality vision in an organization (Serdar Pirtini, 2003).
Overall, many studies on quality control and management in dental care have implied that communication is one of the most crucial aspects that affect the quality of dental services, which also comprises the quality of zirconium crowns. For example, in their systematic review that examined various quality management measures in primary dental care, Byrne et al. (2018) mentioned the theme of communication repeatedly. For instance, they indicated that the quality of communication between dentists and patients affects patient satisfaction. However, Byrne et al. (2018) did not examine TQM as they focused on other quality control measures such as the use of patient questionnaires to survey the quality of communication and information provided. The essence of quality communication between patients and dentists was also implied in another study that was conducted by Timofe and Albu (2016). Most studies have focused on the communication between the dentist and the patient with little emphasis on interprofessional communication such as between dentists and dental lab technicians. However, in whichever way, numerous scholars have indicated that effective communication and care coordination leads to improved quality care in the dental office. For instance, Dental Quality Alliance (2019) indicated that effective communication among other elements of quality dental care affects customer experience leading to either improved customer satisfaction. The observations of the Dental Quality Alliance (DQA) (2019) are in alignment with the objectives of this study considering that TQM was mentioned as the commonly used quality management strategy in dental practice. Similarly, in another study, it was discovered that TQM is positively correlated with teamwork in healthcare settings including dentistry (Hamed Khawka, 2016). Also, Waylen (2017) indicated that one of the benefits of effective communication in dental practice is the enhancement of teamwork. Therefore, the main point of connection between communication dimensions and TQM is teamwork, which has also been associated with improved quality care in healthcare settings including dentistry. The findings of these studies have, therefore, hinted that communication is an important aspect of quality management in dental practice, especially in the production of high-quality zirconium crowns. However, the main observation made from these studies is that there is no study has examined this phenomenon directly in dentistry, especially in the context of effective communication between the dentist and the dental lab technician. Thus, the present study is the first one to fill this literature gap. Also, since Six Sigma is the second most commonly used quality management in dental care, it is also important to examine it further to determine how it reduces the cost of poor quality in dental practice.
Application of Six Sigma Tools and Reduction of Cost of Poor Quality (COPQ)
Managers used the Six-Sigma (DMAIC) methodology in companies such as helicopter component manufacturing to reduce the rate of the defect (Anupama, 2014). Helicopter cooling components are critical because if something goes wrong, the pilot may not survive. Managers used the primary statistical tools to examine the failure of cooling fan assembly at repair division of a company for the helicopter components. Combination of technique that reduces the cost of repair and rework is another practical approach that help the managers not only to reduce the defect rate of products, but also minimize the cost of poor quality and (COPQ) (Anupama, 2014). The goal to use the Six-Sigma is to stop the defects before they appear and reduce the COPQ by adopting a predictive rather a reactive approach toward rejection and rework (Anupama, 2014).
Moreover, in the previous section, it was determined that the use of Six Sigma in healthcare, especially in dentistry is rare but it has been approved to be effective. This observation was affirmed by numerous prior studies. For instance, Antony et al. (2018) discovered that Lean Six Sigma is effective in healthcare, but its focus has been the whole hospital rather than specific departments such as dentistry. This conclusion aligns with how Ahmed (2019) and Tadlaoui, Chafi and Ennadi (2018) approached their research study that was investigating how Six Sigma methodology could be applied in healthcare. Both Ahmed (2019) and Tadlaoui et al. (2018) particularly focused on the whole healthcare system (hospital) with little emphasis on specific departments. The findings of the two studies revealed that Six Sigma methodology could help in improving quality towards patient satisfaction by reducing costs, errors, and defects. Additionally, Salem et al. (2017) implied that in addition to these benefits, the application of Six Sigma in healthcare also improves the work performance of healthcare professionals thus improving the efficiency of healthcare delivery. Applied directly into the context of the present study, these findings imply that if the Six Sigma Methodology is applied in dental practice, especially in the communication between the dentist and dental lab technicians, it could help in reducing costs and errors of producing zirconium crowns. In the previous sections, it was also determined that, for instance, poor communication between the dentist and the dental lab technician can lead to increased costs related to replacing poorly produced or defective crowns that do not meet customer preferences. However, the most crucial aspect is its applicability in specific departments of the healthcare system. If possible, the application of Six Sigma in hospitals can be modelled into smaller settings such as in departments without cost increment. Therefore, the main observation regarding the applicability of Six Sigma in healthcare settings is that no study has examined how it could be used in specific contexts such as dentistry. Future research should aim to fill this gap in the literature to advance research on this area towards achieving better patient satisfaction in healthcare. Therefore, it is important to evaluate the other various methodologies of Six Sigma such as SIPOC and DPMO other than DMAIC to determine the one that could best apply in dentistry.
Application of LQMS, SIPOC, MSA, FMEA, Pareto Chart, DPMO, DPU, and PPM
Managers use six-sigma SIPOC to define the problem, which stands for suppliers, input, process, output, and customers (Sharma, Malik, Gupta, & Jha, 2018). Indian managers used DMAIC to reduce the process variation in the anodizing stage of the amplifier (Sharma et al., 2018). SIPOC is an analysis tool that helps to examine the process of production from suppliers to customers. In the context of overall healthcare whereby dental care is encompassed, DMAIC is the commonly used type of Six Sigma methodology than SIPOC (Al-Qatawneh, Abdallah and Zalloum, 2019). When the researcher performed both a basic and advanced search on Google Scholar using keywords such as Six Sigma, SIPOC, dental care, and zirconium production, no single relevant result was produced, an indication of insufficient literature in this area of interest. However, a hand search for articles that used Six Sigma to improve quality in various healthcare contexts yielded some articles that demonstrated how SIPOC could be used in healthcare. For instance, in their study, Alkinaidri and Alsulami (2018) demonstrated that SIPOC could be used in improving the quality of a referral system in a hospital. Particularly, the scholars indicated that SIPOC helps ensure seamless referral request processing: the process involves receiving a referral request, a consultation process, and finally returning the referral to the requester. Since the dental room is a specialized unit, it receives referral requests from other units of the healthcare system. The quality of processing the referral request matters in healthcare because, according to Li et al. (2017), an effective referral system helps in optimizing resource utilization and distribution in healthcare.
In the context of dental care, SIPOC could be used in improving the effectiveness and efficiency of referral processing thus leading to optimal healthcare delivery with limited resource availability. However, since no study has tested the effectiveness of SIPOC in the setting of dental care, future research should focus on this subject to provide adequate evidence. It is also worth noting that SIPOC cannot be used independently but rather in combination with DMAIC. For example, in their study, Alkinaidri and Alsulami (2018) indicated that SIPOC can be used to achieve the above objectives during the “Define Phase” of DMAIC. This observation was also reiterated in another study that was conducted by Improta et al. (2017) investigating how to improve the quality of infection control measures in hospitals. Improta et al. (2017) indicated that the SIPOC analysis is crucial in the Define Phase of DMAIC. Nevertheless, none of these studies has implied any communication dimensions in this type of Six Sigma methodology. Therefore, future research should also focus on how SIPOC could be applied in the context of improving communication between the dentist and the dental lab technician since it affects the overall quality of dental care including the production of high-quality zirconium crowns. In other words, if DMAIC could be applied in the control and management of the quality of zirconium crowns, scholars should investigate how SIPOC could be integrated into the Define Phase of DMAIC to improve the communication between the dentist and the dental technician.
Pareto chart is another analysis tool that allows the researcher to priorities the defects from the least to the most that happens in the production line. For example, the Pareto analysis produced Pareto chart for the anodizing stage of amplifier and defects classified as pitting (69.45%) and the rest of the errors were due to the total of (33.55%) streaking and crazing defects (Sharma et al., 2018). In healthcare, Pareto analysis has also been widely adopted. For instance, Harel et al. (2016) used Pareto analysis to identify problems that contribute to reduced quality of care. The graph shown in Figure 1 below presents a histogram of the most significant causes of the quality of care problem. The identified causes might be less relevant to the topic under investigation, but the graph has simplified the application of Pareto analysis in the healthcare system. In the United States, the application of Pareto analysis in healthcare was proposed by the Institute for Healthcare Improvement (IHI) whereby it was indicated that it is useful in helping practitioners to concentrate their efforts on the most significant factors thus leading to appropriate addressing of a particular problem (IHI, 2019). In the United Kingdom, the Pareto chart is also commonly used in NHS. For instance, in the East London NHS Foundation Trust, the Pareto chart is used in determining how often particular events or incidents take place in healthcare delivery (East London NHS Foundation Trust, 2019). The Trust follows the 80 ⁄ 20 principle whereby it is assumed that in most cases, roughly 80% of the effects come from 20% of the causes. Therefore, the focus of the improvement efforts should be diverted towards solving the 20% causes to alleviate the 80% effects.
In the production of zirconium crowns, the Pareto chart can help in analyzing the most significant factors influencing the quality of zirconia crowns and the overall quality of dental care. Many factors have been mentioned among them improper handling of the materials, the effectiveness of communication between the dentist and the dental lab technician, among others (Cionca, Hashim and Mombelli, 2016). Little is known about the most significant causes of poor-quality zirconium crowns hence the need for Pareto analysis. Despite the wide application of Pareto analysis in healthcare, little to no research has been conducted to evaluate its effectiveness in dental care, hence a significant literature gap that needs to be filled in future research. For instance, the current study might indicate that the effectiveness of communication between the dentist and the dental lab technician might affect the quality of zirconium crowns and adherence to pre-guide in a statistically significant manner. However, within the limitations of this study, it does not expose the significance level of ineffective communication as a problem affecting the quality of zirconium crowns in a given dental care setting. Nevertheless, it is also apparent that in a specific dental care setting, ineffective communication between the dentist and the dental lab technician is not the only problem facing the production of quality zirconium crowns. Therefore, in the overall improvement in the production line, all these problems need to be listed and their significance levels are determined by the use of Pareto analysis. If the analysis determines that ineffective communication and lack of adherence to prep guide are the most significant problems facing the production of high-quality, then the dental room needs to unleash corresponding efforts to eliminate or reduce them.
Figure 3: A histogram indicating the most significant causes of the quality of care problem as discovered in the study of Harel et al. (2016).
Lean quality management system (LQMS) approaches to problems by reducing the waste, just-in-time (elimination of unnecessary work in process), continuous improvement, perfect quality, optimization, visual management, and human resource engagement (Bacoup, Michel, Habchi & Pralus, 2018). Using LQMS helps companies to obtain certificates if the companies receive no complaint about over two years (Bacoup et al., 2018). Lean management originated in Toyota to eliminate the wastes and cut the steps with no values for the customers. Lean tools are simple in comparison to the six-sigma tool that managers use them with statistical methods (Bacoup et al., 2018).
Moreover, Lean tools are also used in healthcare organizations. Though, there is limited literature on how Lean tools can be used successfully to improve the overall quality of service delivery in healthcare. A few studies have been published indicating how the Lean process might be useful in reducing waste in healthcare organizations. For instance, Tortorella et al. (2019) formulated an evaluation process for ensuring successful implementation of the Lean process to healthcare organizations. The researchers were motivated by the fact that most healthcare organizations experience significant challenges in implementing Lean processes hence the need for a validated evaluation process during the implementation phase.
Indeed, no study has investigated how the Lean process could be helpful in dental care. Probably, ineffective communication between the dentist and dental lab technician carries elements of replication of processes leading to resource wastage and overall customer dissatisfaction. In such a case, the Lean process can help in removing unnecessary steps in the communication between dentist and dental technician thus leading to improved effectiveness. Due to lacking scientific evidence, this is also a significant literature gap. Besides, Carey et al. (2018) indicated that Lean tools are also used in microbiology laboratories to eliminate waste or remove processes that do not add value to the product. It begins with an evaluation process to identify repeat works, high inventory, delays, and so on. If it has been effectively applied in microbiology labs, its application can also be replicated in dental labs with a little bit contextualization to align with the specific operations of the dental lab. Also, Fagerlind Ståhl et al. (2015) discovered that the effective use of Lean tools in organizations adds their competitive value and promotes optimal utilization of limited resources. In most healthcare systems around the world, optimal utilization of limited resources without compromising patient satisfaction and quality of care is highly encouraged. Even in dental care, according to Tulbah et al. (2017), the use of limited resources to produce high-quality zirconium crowns is highly encouraged. Therefore, Lean tools can be useful in enhancing the communication between the dentist and the dental lab technicians as well as improving the quality of zirconium crowns. However, due to missing scientific evidence, this is a significant literature gap. Future studies should focus to fill it by formulating conceptual frameworks that permit the successful application of Lean into dental care settings.
Also, the Six-sigma is a measuring tool and measuring system analysis (MSA) and analysis tools such as Pareto analysis that is a useful tool to help to detect quality issues. In healthcare, the MSA system has been implemented in a wide variety of contexts. In their study, Mgbere, Singh and Arafat (2015) discovered that successful implementation of MSA in HIV preventive care services leads to a reduction in measurement variations thus resulting in improved work performance output and eventual improvement in the quality of preventive care services and overall patient outcomes. Also, Furterer and Hernandez (2019) indicated that MSA has been widely used in healthcare to assess the accuracy and use of equipment and devices. The researchers further observed that MSA could be used in assessing the accuracy of a human element in a healthcare diagnosis service process. Since diagnosis service processes take place nearly in all healthcare departments including dentistry, it can be said that MSA can successfully be used to improve the accuracy of human elements as well as equipment and devices. Particularly, in the context of dental care and specifically the communication between the dentist and dental technicians, human elements, as well as devices and equipment, are involved frequently. MSA could help in assessing their accuracy to deliberate the need for improvement using other quality control and management tools such as Lean and Six Sigma. Up to this point, it is also apparent that quality management tools are unique in the quality improvement process. Thus, to yield optimal results for quality, a combination of these tools is mandatory thus demonstrating further the complexities involved in quality management in healthcare organizations. These complications make it extremely challenging to implement these tools in specific departments like dentistry perhaps due to cost of implementation and the high levels of expertise needed. The next paragraph presents how another tool process called FMEA can be combined with these other tools to improve the overall quality of care in healthcare organizations.
Improving quality is the final goal and using process failure mode, and effects analysis (FMEA) focuses on factors such as men, methods, material, machinery, measurement, and environment. Controlling is another step that managers use a control chart to suggest changes that monitor the changes that improve the quality of products. FMEA is one of the most extensively used Six Sigma tool in health care. In a systematic review, it was discovered that most scholars recommend the use of FMEA in healthcare by considering it a useful and effective tool (Dastjerdi et al., 2016). Indeed, many studies like Liu et al. (2018) have evaluated its application in various contexts of healthcare. For instance, Li, He and Wang (2017) evaluated how FMEA can be used to improve the management of catheter-related bloodstream infection in ICU. The authors concluded that FMEA can reduce incidences of a blood infection in this setting, improve the quality of nursing, reduce medical expenses, and improve the security of central nervous catheterization (Li et al., 2017). Xue et al. (2016) also discovered that FMEA can help in improving pain management and improve the quality of nursing care in the anesthesia recovery period.
Also, unlike most of Six Sigma methodologies that have been discussed before, FMEA is the only methodology that has been applied in dental contexts in multiple times in prior research. For instance, Kirkire, Rane and Jadhav (2015) proposed a model for risk mitigation during dental product manufacturing to minimize failures using the FMEA methodology. The findings of the study concluded that FMEA is effective in avoiding the duplication of processes and improves the conversion of expert cognition into information to get values of risk factors. This conversion involves improved effectiveness of interprofessional communication. For example, dentists possess the expertise of how zirconium crowns should be designed to meet customer demands whereas dental technicians possess the expertise of executing the plan of the dentist. Therefore, FMEA methodology could also be narrowed down and be applied in the context of improving the effectiveness of communication between the dentist and the dental technician. However, the significance of a future study that replicates the methodology that was used by Kirkire et al. (2018) to determine of FMEA could be used to improve communication will rely upon the findings of the present study. Particularly, if the current research discovers that there is a strong correlation between the quality of zirconium crowns and the effectiveness of communication between the dentist and the dental technician, then future research will hold a lot of significance in dental practice.
Likewise, other studies have proved that FMEA´s application in dental practice is diverse. For instance, Akifuddin (2015) discovered that FMEA is effective in reducing complications of local anesthesia in dental healthcare setups through improved quality of management. Reduction in health complications is generally associated with lower medical costs. Also, the United States´ Institute for Healthcare Improvement (IHI) (n.d.) indicated that this methodology can be used by government policy formulators to improve access to prosthetic dental services. Overall, FMEA holds potential in improving the quality of zirconium crowns. Hence, future studies should focus on drafting a conceptual framework through which it can be used effectively in this context.
Nonetheless, the Six-Sigma concept aims to keep the defect levels below 3.4 defectives per million opportunities (DPMO) (Raju and Sowdaminit, 2015). Quality control managers use six-sigma to reduce defects, and the goal is to increase the sigma value from toward Six Sigma, which is an indication of the lowest possible error (3.4 per million) (Raju and Sowdaminit, 2015). In the context of manufacturing zirconium crowns, it was highlighted in the previous sections that the occurrence of defects during the different procedures of manufacturing affects the chipping of veneering porcelain on zirconia-based ceramic frameworks. Therefore, controlling the number of defect occurrences per million opportunities during the manufacturing of zirconium crowns is crucial to maintaining high-quality standards (Kontonasaki et al., 2019). The main advantage of DPMO is that it can be converted into sigma metric and vice versa thus making the overall Six Sigma methodology highly effective both in industry and business (Coskun, Serteser and Ünsal, 2018). If the manufacturing of zirconium crowns utilizes the Six Sigma methodology, all data need to be converted into DPMO and then focus on the phase where more defectives occur. In this way, occasioning risk mitigation becomes less challenging resulting in the overall improvement of the quality of zirconium products. Additionally, other defect indicators are defects part per million (PPM) and defect per units (DPU) used by the lean managers to calculate the defect rate of manufacturing products.
Current DMAIC Approach to Quality Improvement
General Electric (GE) used the six-sigma program in Brazil to improve issues such as a market share on a global scale (Schmidt et al., 2018). Using six-sigma is not limited to any business, and quality managers use it to improve the quality of produces. The Indian company that provides anodized amplifiers is one of the companies that took the initiative by using DMAIC process of six-sigma to enhance the quality of their products and reduce process variation (Sharma, Malik, Gupta, & Jha, 2018).
Conceptual Framework Literature
A conceptual framework comprised of ideas that provides structure to a theory in a research to guide the study and find connections between different concepts (Dziak, 2018). Interpersonal communication (two-way communication) is the conceptual foundation for the study (Serdar PİRTİNİ, 2003). Germinal studies of interpersonal communication and TQM find in studies of the Serdar PİRTİNİ (2003) that included the concept of interpersonal communication with the total quality management (TQM). The process of interpersonal communication studied by Shannon and Weaver’s model of communication (1949) which in the basic format that comprised of sender, the message, the channel, the receiver, and the noise as an additional component (Min, Koo, & DeLong, 2015). The most important part of the Shannon and Weaver’s models is the feedback that comes from the customers and help to improve the quality of services and products with a two-way communication (Min et al., 2015). The correlational study of quality and communication depend on the feedback that comes from dentists about the quality of work.
The study of interpersonal communication will be based on factors such numerical, feedback, privacy, goal, and mutual influence (Long & Vaughan, 2007). Interpersonal communication depends on the number of people, medium used for the communication, interaction in privacy or public, and tasks that influences others (Long & Vaughan, 2007). The major dimensions of communication vary from human-human, human-machine, and human-society (Serdar PİRTİNİ, 2003). Human-to-human communication is the focus of the study and conceptual framework provides guidance to analyze the relationship between quality and communication in dental offices.
Methodology Literature
The research methodology used in the different articles and documents included in this review are either qualitative or quantitative. In most cases, the reports about the different qualitative assurance practices, such as TQM, Six Sigma are mostly used for general references. Therefore, no specific quantitative procedure was used to present the information in the different document sources. For the discussion of the importance of communication and the different quality aspects of dental crowns, most studies are quantitative in nature. For this study, the methodology will be quantitative because the focus of the purpose, research questions, and hypotheses of the study is the relationship between independent variables (e.g., efficiency of technician-dentist communication, adherence to prep-guide) and dependent variable (e.g., overall quality of zirconium crowns).
Dentist, Hygienist, and Dental Treatment Outcome
Cooperation between dentist band the team within the dental office is an essential fact that impacts the quality of treatment (Hamasaki, Kato, Kumagai, & Hagihara, 2017). Dental hygienists are a critical team player in dental office and quality of service and products depend on their technical ability (Hamasaki et al., 2017). Dentist and hygienist must work together to serve the patients, but miscommunication between them can cause serious problem for the office. The correlational study of communication between hygienist suggested that there is a significant correlation between interprofessional communication and patients’ satisfaction (Hamasaki et al., 2017). The method used to determine the association between communication and patient satisfaction by giving questionnaires to the patients (total 250), and dentists and hygienist complete the rest of the survey separately (Hamasaki et al., 2017). A five-point Likert scale implemented to measure the satisfaction from very insufficient to very sufficient (Hamasaki et al., 2017). One-way analysis of variance (ANOVA) used to examine the patients’ satisfaction based on the dentist and hygienist perceptions (Hamasaki et al., 2017). A multiple regression analysis used to evaluate the factors affecting the patient satisfaction (patient, hygienist, and dentist), and PASW® Version 18 used for statistical analysis (Hamasaki et al., 2017). Using a quantitative method with correlational orientation helps to examine communication and quality issues in dental offices, which depend on secure communication between the team members.
Research Design Literature
The literature in this section provides scholarly knowledge about the research design the help to obtain the proper plan for the study. The primary goal of the literature is to provide insight into the correlational research design that helps to determine the relationship between compliances of the prep-guide by dentists and quality improvement in dental laboratories. The research design is quantitative non-experimental correlational. Questionnaire is the instrument to collect the data.
A non-experimental approach involves an uncontrolled setting wherein variables are measured as they occur (Johnson & Christensen, 2019). For this study, the researcher will use a non-experimental design because it is more appropriate to address the research questions of the study. An experimental design was not appropriate for this study as the focus was to identify the relationships of the variables without manipulating the data. Moreover, a correlational design is used in researches when the researcher needs to explore the extent or the strength of the relationship between the independent and dependent variables. Based on the purpose of the study, the independent variables (e.g., efficiency of technician-dentist communication, adherence to prep-guide) and dependent variable (e.g., overall quality of zirconium crowns).
Conclusions
The literature review contributes knowledge about the interconnectivity of the communication and quality improvement in which dentists and technicians must communicate continuously and mutually. Methodology and history of quality control in different companies, especially dental laboratories reveal that managers need to work the team members and keep everyone up to date to improve the overall customer satisfaction. Researcher explores articles that concentrate on TQM and techniques such as the Six-Sigma methodology and DMAIC process to explore possible solution to improve the quality of products in dental office. The purpose of this quantitative correlational study is to identify the significance of the relationships between the efficiency of technician-dentist communication, adherence to prep-guide, and the different quality indicators of zirconium crowns. The literatures presented information about the users of Six-Sigma that aimed to reduce the defect rate in the production line. The researcher explores the literature that presents quality control issues and possible solutions that help to improve the quality of the products.
Chapter Summary
The literature review related to studies that already covered the importance of the dental technicians’ compliances of dentists written guidelines on the prescriptions. The literature review provided insight into the TQM and techniques such as six-sigma and DMAIC methodology and SIPOC process used by major companies such as GE, Motorola, and Toyota. The previous studies introduced TQM techniques to improve quality in manufacturing sectors. The previous studies used methodologies such as cost of poor quality (COPQ) and just in time (JIT) techniques to reduce the waste and activities that increase operational cost. These studies help the researcher define the problem and help the dental business to consider prep-guide and protocols that help to improve the quality of dental products. In conclusion, researcher goal is to explore the TQM and using Pareto chart to classify the issues in dental business and examine the relationship between communication and the quality issues listed in the questionnaire.
Concepts that introduced in the literature review includes lean quality management system (LQMS) that managers use to reducing the waste with continuous improvement (Bacoup, Michel, Habchi & Pralus, 2018). Using DMAIC is a process of Six-Sigma to enhance the quality of products that reduce waste (Sharma, Malik, Gupta, & Jha, 2018). SIPOC is another concept used among managers in TQM to define the problem, which stands for suppliers, input, process, output, and customers (Sharma, Malik, Gupta, & Jha, 2018). TQM philosophy focuses on customer satisfaction for every single time with no exception, and quality should build in the process of production (Serdar PİRTİNİ, 2003). Communication is the center of study in this study that impacts the quality issues in a dental office, so considering the hygienist ability to perceive effective communication and barriers examined in the literature review (Walker, Jackson, & Maxwell, 2016). The literature review covered the subject of patients’ satisfaction and factors such as responsiveness, waiting time, and admission process (Bahadori, Raadabadi, Ravangard, & Baldacchino, 2015). Communication methods such as web content management system (WCMS) and paper communication methods addressed in the study due to the advancement of technology. Finally, the researcher explored reasons such as quality, excellent communication, and reasonable pricing that improves the relationship between dentists and technicians (Burns, 2013).
Chapter 3
Methodology
The purpose of the study is to find relationship between the efficiency of technician-dentist communication, adherence to prep-guide as a communication tool, and quality of zirconium crowns. The goal is to find the relationship between adherence to prep-guide and quality issues such as shade, shape, fit, overall quality, contacts, and seating time. A quantitative methodology and correlational research design applied to the study to examine the effectiveness of dentist-technician communication and the relationship between quality of zirconium crowns and understanding between technicians and dentists.
The discussion in previous chapter explored the scholarly articles related to communication and quality issues in dental filed and manufacturing. Articles provides data about the relationship between the adherence to prep-guide and quality of zirconium crowns and efficiency of technician-dentist communication. The chapter 3 provides methodology that implemented to examine the relationship between the adherent to prep-guide, efficiency of technician-dentist communication, and quality of zirconium crowns. The chapter provide data about the population, sampling, consent information, validity and reliability. Data collection procedure and instrumentation are the focus of the study which follows with the data analysis and summary of the chapter.
Research Methodology and Design Appropriateness
A quantitative method introduced in chapter 1 to examine the association between dentist adherence to prep-guide, technician-dentist efficiency of communication, and quality of zirconium crowns. The quantitative method suggested to collect and analyze data to answer the research question. Three hypotheses presented in chapter 1 that suggests relationship between adherence to prep-guide, efficiency of technician-dentist communication with the quality of zirconium crowns. The correlation design suggested to examine the relationship between adherence to prep-guide, efficiency of technician-dentist communication and zirconium quality issues.
Research Method Appropriateness
A quantitative method talks in terms of change in variables (mathematics) or relationships among sets of variables (regression). In quantitative research, we want our theories and findings to have verisimilitude, and the extent to which we can make a case that our theories and findings have verisimilitude is the bottom line in quantitative communication science BAILEY, K. (2007).
Quantitative research involves variables. Variables are symbols to which numerals or numbers are assigned. Variables are also observable things that vary or that can take on different values. In this sense, variables are contrasted with both constants and constructs. Constants are things whose values are fixed; they do not vary (Levine, 2009).
Variables can be related to each other in a variety of different ways. Given that the goal of quantitative communication research is usually to document and explain how variables are related, knowing about different types of relationships between variables is essential.
One possibility is that no relationship exists. That is, the variables are completely unrelated, and there is no covari-ance. (Levine, 2009).
Levine, T. (2009). Quantitative approaches to communication research. In W. F. Eadie 21st century communication: A reference handbook (Vol. 2, pp. 57-64). Thousand Oaks, CA: SAGE Publications, Inc. doi: 10.4135/9781412964005.n
BAILEY, K. (2007). Quantitative methodology. In C. D. Bryant & D. L. Peck 21st century sociology (Vol. 2, pp. I-108-I-117). Thousand Oaks, CA: SAGE Publications, Inc. doi: 10.4135/9781412939645.n10
Design Appropriateness
In statistics, correlation is more specifically defined as a measure of the strength, or consistency, of the linear relationship between two variables in a population. Graphically, this statistic indicates how well the scatterplot obtained by representing the observations on a Cartesian plane with the two variables as dimensions fits along a straight line. Correlation is most commonly measured—or estimated, when only a sample is available—with the Pearson product-moment coefficient (ρ or r in statistical notation, respectively, for populations and samples), a standardized indicator whose value ranges between -1 (perfect negative correlation) and 1 (perfect positive correlation), and where 0 denotes the absence of correlation. correlation can be positive if the variables move in the same direction (they both increase or decrease at the same time), or negative if they move in opposite directions (when one variable increases, the other decreases). (Kurian, 2011).
A set of statistical techniques for measuring the extent to which two variables are related. For interval-scale data, the strength of relationships can be expressed quantitatively by using a correlation coefficient such as the Pearson product-momentcorrelation coefficient (r) which varies between –1.0 and +1.0. A value of the coefficient of +1.0 indicates perfect positive correlation (in the sense that increases in one variable accompany increases in the other) whilst a value of –1.0 indicates a perfect negative correlation (increases in one variable accompany decreases in the other; they are negatively related). A correlation coefficient of zero indicates no correlation. The degree of similarity does not allow one to infer that variations in one quantity actually cause variations in the other. Multiple correlation measures the extent to which more than one variable are related. Partial correlation measures the extent to which variables are related while holding constant the statistical effects of one or more variables. (Saich, 2014).
Kurian, G. T. (2011). Correlation. In The Encyclopedia of Political Science (pp. 341-341). Washington, DC: CQ Press doi: 10.4135/9781608712434.n330
Saich, P. (2014). Correlation analysis. In J. Matthews (Ed.), Encyclopedia of environmental change (pp. 226-226). Thousand Oaks,, CA: SAGE Publications, Ltd. doi: 10.4135/9781446247501.n863
Research Questions and Hypotheses
A hypothesis is defined as a proposition designed to be tested in the research project. To achieve testability, all variables in the hypothesis must be clearly stated and must be capable of empirical measurement. Research hypotheses may be univariate, bivariate, or multivariate ,,,,,,,,,,,,,,,,, formulate hypotheses using the available variables
(BAILEY, 2007).
quantitative concepts are ubiquitous
Population and Sample
a population is the entire collection of entities one seeks to understand or, more formally, about which one seeks to draw an inference. Consequently, defining clearly the population of interest is a fundamental component of research design because the way in which the population is defined dictates the scope of the inferences resulting from the research effort. (Huck, Beavers, & Esquivel, 2010).
simple random samples, each member of the population must have an equal probability of being included in the sample. It follows that each possible sample of size n has an equal probability of being selected from the population. After a list of the population’s members (i.e., the sampling frame) is created, a random number generator, a random numbers table, or some other unbiased method is used to generate the sample. (Huck, Beavers, & Esquivel, 2010).
Huck, S., Beavers, A. & Esquivel, S. (2010). Sample. In N. J. Salkind (Ed.), Encyclopedia of research design (pp. 1395-1299). Thousand Oaks, CA: SAGE Publications, Inc. doi: 10.4135/9781412961288.n395
Informed Consent and Confidentiality
Geographic Location and Data Collection
Instrumentation
Questionnaire construction, as a middle component of the research sequence, is subject to a number of constraints that are not always well recognized. First and foremost is the necessity for the questionnaire to faithfully measure the concepts in the hypotheses. But other constraints are also imposed after questionnaire construction, chiefly sampling constraints, data-collection constraints, and quantitative data-analysis constraints. The questionnaire constrains the sampling design. If the questionnaire is very short and easily administered, this facilitates the use of a complicated sample design. However, if the questionnaire is complex, then sample size may need to be reduced. The construction of a large and complex questionnaire means that it is difficult and time-consuming to conduct a large number of interviews.
the questionnaire must be designed to collect data that meet the statistical assumptions of the quantitative techniques to be used. Questionnaires can quickly become long and complicated. Furthermore, there is a tendency to construct closed-ended questions with not more than seven answer categories. While such nominal or ordinal data are often used in regression analyses, they are marginally inappropriate for ordinary least squares (OLS) regression and other quantitative techniques that assume interval or ratio data. (BAILEY, 2007).
Indicator variables …
Dependent variables Definition
Overall quality Overall quality determines the quality if the quality of crowns is acceptable, excellent, or unacceptable. (Appendix A)
Seating time Seating time is the time that dentists spend to fit the crown in the mouth (Appendix A)
Rx followed Rx is the written structure (paper commination) that explains the dentist’s expectations (prescription) (Appendix A)
Fit Adapting the prosthetic edge to the abutment which is
the (prepped tooth) (Appendix A)
Occlusion Relationship between upper and lower jaws (Appendix A)
Contacts Contacts surface between adjacent teeth (Appendix A)
Contour Overall shape of the crown (Appendix A)
Shade Color of the crown that matches the natural tooth (Appendix A)
Anatomy Detailed feature of natural tooth (Appendix A)
Emergence profile Blending the crown from the side with the rest of the crowns
Margin Edge of the prosthesis crown (Appendix A)
Due date Appointment date that patient comes back to dental office
(Appendix A)
Predictor variables …
Predictor variables Definition
Adherence to Prep-Guide A communication and training tool for the dentist to
prepare the tooth for the crown (Appendix A)
Effectiveness of Dentist-Technician Communication The level of proper understanding between technicians and dentists (Appendix A)
Field Test or Pilot Testing
Validity and Reliability
Measurement is the assignment of numbers to attributes or properties of people, objects, or events based on a set of rules (Stevens, 1968).( Aguinis, Henle, & Ostroff, 2001).
Reliability refers to the extent that a measure is dependable, stable, and consistent over time. If a measure is reliable, there is consistency between two sets of scores on a measure( Aguinis, Henle, & Ostroff, 2001).
The concept of reliability assumes that scores obtained from a measure include a ‘true’ score or accurate representation of an individual’s level of the attribute being measured. For example, if we give a typing test to job applicants, we assume that the test is assessing their true ability to type( Aguinis, Henle, & Ostroff, 2001).
In order to increase the reliability of a measure, errors of measurement must be minimized. Ideally, they should be completely eliminated. By decreasing error and subsequently increasing reliability, it is more likely the measure will reflect an individual’s true possession of the attribute measured. ( Aguinis, Henle, & Ostroff, 2001).
Methods for estimating the reliability of a measure use the correlation coefficient to assess the relationship or degree of consistency between two sets of scores. The reliability coefficient can range from 0 to 1, with numbers closer to one indicating high reliability and little measurement error, and values closer to zero indicating low reliability and a large amount of measurement error. ( Aguinis, Henle, & Ostroff, 2001).
The quality of a research design is typically assessed in terms of internal and external validity. Internal validity refers to how much confidence we have that variation in the dependent variable is really attributable to the independent variable and not some spurious, nuisance variable. External validity refers to the extent to which findings can be generalized to other people, situations, and times. (Levine, 2009).
Nominal Scales or any other
A nominal scale is the most basic and it involves assigning numbers as labels to individual objects (e.g., telephone numbers) or categories of objects (e.g., sex, organizational unit). Nominal scales determine whether objects belong in the same or different categories (e.g., male or female) based on a given attribute (e.g., sex). Thus, nominal scales classify people or objects. ( Aguinis, Henle, & Ostroff, 2001).
Ordinal scales involve assigning numbers to people or objects so that their rank order can be determined. That is, ordinal scales help decide if one person is equal to, greater than, or less than another based on a given attribute. For example, a supervisor believes María is a better performer than Bob, thus María is given a 2 while Bob is assigned a 1 to show María has a higher performance ranking than Bob. However, this does not indicate the magnitude of the difference between María’s and Bob’s performance levels, we just know that María is better than Bob. ( Aguinis, Henle, & Ostroff, 2001).
Interval Scales
Interval, like ordinal scales, assign numbers to reflect whether individuals or objects are greater than, less than, or equal to each other. However, interval scales also indicate the difference between objects on a particular attribute. ( Aguinis, Henle, & Ostroff, 2001).
Ratio Scales
Ratio scales have a true zero point. The true zero point is the point at which no amount of the attribute is present. Because a zero point can be determined, the ratio between actual scores of an attribute can be examined. ( Aguinis, Henle, & Ostroff, 2001).
Aguinis, H., Henle, C. & Ostroff, C. (2001). Measurement in work and organizational psychology. In N. AndersonD. S. Ones & H. K. Sinangil Handbook of industrial, work & organizational psychology – volume 1: Personnel psychology (Vol. 2, pp. 27-50). London: SAGE Publications Ltd doi: 10.4135/9781848608320.n3
Internal Validity
Internal validity is an evaluation of a special type of “internal relationship” that can occur between variables in a study. Specifically, internal validity evaluates whether a cause-and-effect relationship between variables can be determined (Barron, K., Brown, A., Egan, T., Gesualdi, C. & Marchuk, 2008).
A concern with whether the variation in the independent variable(s) caused or influenced observed variation in the dependent variable(s). Threats to internal validity (e.g., selection effects, history, mortality, etc.) should be identified before making any conclusions. Furthermore, a research study can only be internally valid if it measures what it is intended to measure. (Sullivan, 2009).
Barron, K., Brown, A., Egan, T., Gesualdi, C. & Marchuk, K. (2008). Validity. In S. F. Davis & W. Buskist 21st century psychology: A reference handbook (Vol. 2, pp. I-55-I-64). Thousand Oaks, CA: SAGE Publications, Inc. doi: 10.4135/9781412956321.n7
Sullivan, L. E. (2009). Internal validity. In The SAGE glossary of the social and behavioral sciences (pp. 265-266). Thousand Oaks, CA: SAGE Publications, Inc. doi: 10.4135/9781412972024.n1344
External Validity
new external validity terms have been coined to capture unique generalizability issues in particular field
Specifically, population validity entails the extent to which findings can be generalized beyond the participants of a study to the population at large (Barron, K., Brown, A., Egan, T., Gesualdi, C. & Marchuk, 2008).
The degree to which research findings can be generalized. External validity includes the extent to which research findings can be applied to the population of interest. External validity also includes the extent to which research findings can be extended to different people, places, settings, times, outcomes, and treatment variations. (Sullivan, 2009).
Data Analysis
Correlation is a statistical measure of the relationship, or association, between two or more variables. There are many different types of correlations, each of which measures particular statistical relationships among and between quantitative variables. (Shapiro, 2008).
The value of the correlation between any two variables is typically given by a correlation coefficient, which can take on any value between and including − 1.00 (indicating a perfect negative relationship) up to and including +1.00 (indicating a perfect positive relationship). (Shapiro, 2008).
Probability
Statistical significance testing may be used when working with a random sample from a population, or a sample that is believed to approximate a random, representative sample. Statistical significance testing calls for subjective judgment in establishing a predetermined probability (ranges between 0 and 1.0) of making an inferential error caused by the sampling error. When using statistical significance testing, it requires the use of two forms of probability (P): calculated and critical. Statistical significance is met when P(CALCULATED) is less than P(CRITICAL); when this is the case, the null hypothesis can be “rejected.” Only when the null hypothesis is rejected are the results called “statistically significant.” This simply implies that the sample results are relatively unlikely, given the assumption that the null hypothesis is exactly true. (Salkind, 2008).
P(Critical)
One of the probabilities, P(CRITICAL), is also referred to as “alpha.” P(CRITICAL) is the probability of making a Type I error when testing a null hypothesis. A Type I error occurs when rejecting a null hypothesis that is true. Another possible type of error that can occur is a Type II error, which occurs when the null hypothesis is not rejected and it is false. The P(CRITICAL) is usually set before collecting the data and tends to be a small number. The most frequent alpha levels used are .05 and .01; by using a small number, the probability of error is minimized. (Salkind, 2008).
Phi and Crame ´r’s V Coefficients
The phi and Crame´r’s V coefficients are used to evaluate the strength of relationship between two nominal-level variables when the chi-square statistic has been found to be significant. The phi is used when the two nominal-level variables are dichotomous; the Crame´r’s V coefficient is used with nominal-level variables with more than two levels.
Spearman Rank-Order Correlation
The Spearman rank-order correlation coefficient (also known as Spearman’s rho or rs)isoneofthe best-known and most frequently used nonparametric statistics. It is used to examine the relationship between two continuous variables (e.g., age and level of depression). Its parametric alternative is the Pearson product-moment correlation coefficient. (Pett, 2008).
Like the point biserial correlation, Spearman’s rho is a special case of the Pearson r but is based on the ranking of observations, not their actual values. This test statistic can range in value between −1.0 and +1.0 with higher absolute values indicating a stronger relationship. The squared values of Spearman’s rho offer a reasonable estimate of the strength of the relationship between the two continuous variables of interest. (Pett, 2008).
Pett, M. (2008). Nonparametric statistics. In S. Boslaugh (Ed.), Encyclopedia of epidemiology (Vol. 1, pp. 737-743). Thousand Oaks, CA: SAGE Publications, Inc. doi: 10.4135/9781412953948.n321
Salkind, N. J. (2008). Statistical significance. In Encyclopedia of educational psychology (Vol. 1, pp. 944-945). Thousand Oaks, CA: SAGE Publications, Inc. doi: 10.4135/9781412963848.n261
Shapiro, J. (2008). Correlation. In P. J. Lavrakas (Ed.), Encyclopedia of survey research methods (pp. 155-156). Thousand Oaks, CA: SAGE Publications, Inc. doi: 10.4135/9781412963947.n110
Decision Rule
Securing the Data
Summary
References
Aboras, M. M., Muchtar, A., Azhari, C. H., & Yahaya, N. (2014). Type of failure of zirconia-based ceramics in dental laboratory in Misurata, Libya. Applied mechanics and materials, 575, 22-25. doi: http://dx.doi.org.contentproxy.phoenix.edu/10.4028/www.scientific.net/AMM.575.22
Ahangari, A., Ardakan, K., Mahdavi, F. and Ardakani, M. (2015). The Effect of two Shading Techniques on Value of Zirconia-Based Crowns. 16(2), pp.129-133.
Ahmed, S. (2019). Integrating DMAIC approach of Lean Six Sigma and theory of constraints toward quality improvement in healthcare. Reviews on Environmental Health, 0(0).
Akifuddin, S. (2015). Reduction of Complications of Local Anaesthesia in Dental Healthcare Setups by Application of the Six Sigma Methodology: A Statistical Quality Improvement Technique. JOURNAL OF CLINICAL AND DIAGNOSTIC RESEARCH.
Akifuddin, S. (2015). Reduction of Complications of Local Anaesthesia in Dental Healthcare Setups by Application of the Six Sigma Methodology: A Statistical Quality Improvement Technique. JOURNAL OF CLINICAL AND DIAGNOSTIC RESEARCH.
Alammari, M. and Albagar, R. (2018). Assessment of the perceived communication competence of senior undergraduate dental students: A study of the quality of data and orders written in prosthodontics’ laboratory forms. Journal of International Oral Health, 10(1), pp.16-20.
Alkinaidri, A. and Alsulami, H. (2018). Improving Healthcare Referral System Using Lean Six Sigma. American Journal of Industrial and Business Management, 08(02), pp.193-206.
Alomari, M., & Chadwick, R. G. (2011). Factors influencing the shade matching performance of dentists and dental technicians when using two different shade guides. British dental journal, 211(11), 7. doi: http://dx.doi.org/10.1038/sj.bdj.2011.1006
Al-Qatawneh, L., Abdallah, A. and Zalloum, S. (2019). Six Sigma Application in Healthcare Logistics: A Framework and A Case Study. Journal of Healthcare Engineering, 2019, pp.1-12.
Alshiddi, I. F. (2014). Communication between dental office and dental laboratory: From Paper-based to web-based. Pakistan oral & dental journal, 34(3) Retrieved from https://search.proquest.com/docview/1695990809?accountid=35812
Antony, J., Palsuk, P., Gupta, S., Mishra, D. and Barach, P. (2018). Six Sigma in healthcare: a systematic review of the literature. International Journal of Quality & Reliability Management, 35(5), pp.1075-1092.
Anupama, P. (2014). Adoption of Six Sigma DMAIC to reduce cost of poor quality. International journal of productivity and performance management, Vol. 63 Issue: 1, pp.103-126, https://doi.org/10.1108/IJPPM-01-2013-0018
Apsari, A. (2017). The Importance of Abutment Teeth Preparation Guide for Telescopic Double Crown Restorations with Friction Element. DENTA, 11(1), 69.
Arbab Ali, S., Khalifa, N. and Nasser Alhajj, M. (2018). Communication Between Dentists and Dental Technicians During the Fabrication of Removable Partial Dentures in Khartoum State, Sudan. Acta Stomatologica Croatica, 52(3), pp.246-253.
Avgousti, K. (2013). Research Philosophy, methodology, quantitative, and qualitative methods. The Cyprus journal of sciences, 11, 33-43. Retrieved from https://search.proquest.com/docview/1516144410?accountid=35812
Ayse, B. C., & Schou, L. (2014). Interrelation between patient satisfaction and patient-provider communication in diabetes management. The scientific world journal, 2014 doi: http://dx.doi.org/10.1155/2014/372671
Bacoup, P., Michel, C., Habchi, G., & Pralus, M. (2018). From a quality management system (QMS) to a lean quality management system (LQMS). TQM Journal, 30(1), 20-42. Retrieved from https://search-proquest-com.contentproxy.phoenix.edu/docview/1977763704?accountid=35812
Bahadori, M., Raadabadi, M., Ravangard, R., & Baldacchino, D. (2015). Factors affecting dental service quality. International journal of health care quality assurance, 28(7), 678-689. doi: http://dx.doi.org/10.1108/IJHCQA-12-2014-0112
Bin-Shuwaish, M. (2017). Compliance of dental laboratory technicians with dentists’ instructions for fabrication of a PFM crown. The Saudi Journal for Dental Research, 8(1-2), pp.35-41.
Bin-Shuwaish, M. S. (2017). Compliance of dental laboratory technicians with dentists’ instructions for fabrication of a PFM crown. The Saudi journal for dental research, 8(1–2), 35–41. https://doi-org.contentproxy.phoenix.edu/10.1016/j.sjdr.2016.06.001
Brown, J. S., Collins, A., & Duguid, P. (1989). Situated cognition and the culture of learning. Educational Researcher, (1), 32. https://doi.org/10.2307/1176008
Burns, L. (2013). Why Dentists Are Changing Laboratories. Proofs, 96(4), 32–36. Retrieved from http://search.ebscohost.com/login.aspx?direct=true&AuthType=shib&db=bth&AN=87510537&site=eds-live&scope=site
Byrne, M., Tickle, M., Glenny, A., Campbell, S., Goodwin, T. and O’Malley, L. (2018). A systematic review of quality measures used in primary care dentistry. International Dental Journal, 69(4), pp.252-264.
Carey, R., Bhattacharyya, S., Kehl, S., Matukas, L., Pentella, M., Salfinger, M. and Schuetz, A. (2018). Implementing a quality management system in the medical microbiology laboratory. Clinical Microbiology Reviews, 31(3).
Cionca, N., Hashim, D. and Mombelli, A. (2016). Zirconia dental implants: where are we now, and where are we heading? Periodontology 2000, 73(1), pp.241-258.
Cohen, J. (1988). Statistical power analyses for the social sciences. Hillsdale, NJ: Lawrence Erlbauni Associates.
Coskun, A., Serteser, M. and Ünsal, I. (2018). Sigma metric revisited: True known mistakes. Biochemia medica, 29(1), pp.142-148.
Danese, P., Romano, P., & Bortolotti, T. (2012). JIT production, JIT supply and performance: Investigating the moderating effects. Industrial Management & Data Systems, 112(3), 441-465. doi:10.1108/02635571211210068
Dastjerdi, H., Khorasani, E., Yarmohammadian, M. and Ahmadzade, M. (2016). Evaluating the application of failure mode and effects analysis technique in hospital wards: a systematic review. Journal of Injury and Violence Research, 9(1), pp.51-60.
Dental Quality Alliance (2019). Quality measurement in dentistry: A Guidebook. Improving Oral Health through Measurement. [online] pp.1-68. Available at: https://www.ada.org/~/media/ADA/DQA/2019_Guidebook.pdf?la=en [Accessed 28 Nov. 2019].
Eakle, W. and Hatrick, C. (2015). Dental Materials: Clinical Applications for Dental Assistants and Dental Hygienists. 3rd ed. Elsevier.
East London NHS Foundation Trust (2019). Pareto Chart: Quality Improvement. [online] Qi.elft.nhs.uk. Available at: https://qi.elft.nhs.uk/resource/pareto-charts/ [Accessed 29 Nov. 2019].
El-Sayed, A. and Ahmed Mousa, M. (2015). The impact of cooperative learning in teaching communication skills for psychiatric nursing Students. The Eurasia Proceedings of Educational & Social Sciences (EPESS), 3, pp.74-77.
Etikan, I., Musa, S. A., & Alkassim, R. S. (2016). Comparison of convenience sampling and purposive sampling. American journal of theoretical and applied statistics, 5(1), 1-4.
Fagerlind Ståhl, A., Gustavsson, M., Karlsson, N., Johansson, G. and Ekberg, K. (2015). Lean production tools and decision latitude enable conditions for innovative learning in organizations: A multilevel analysis. Applied Ergonomics, 47, pp.285-291.
Fowler, S. B., & Lapp, V. (2019). Sample size in quantitative research: Sample size will affect the significance of your research. American nurse today, 14(5), 61–62. Retrieved from http://search.ebscohost.com/login.aspx?direct=true&AuthType=shib&db=ccm&AN=136584614&site=eds-live&scope=site
Furterer, S. and Hernandez, E. (2019). Improving the Healthcare Quality Measurement System Using Attribute Agreement Analysis Assessing the Presence and Stage of Pressure Ulcers. International Journal of Statistics and Probability, [online] 8(4), pp.47-59. Available at: https://pdfs.semanticscholar.org/2a4e/66add4941557c0ddbc3aae57d887d6bd123a.pdf [Accessed 29 Nov. 2019].
Gaylor, L. (2016). The Administrative Dental Assistant. Elsevier Health Sciences.
Gignac, G. E., & Szodorai, E. T. (2016). Effect size guidelines for individual differences researchers. Personality and individual differences, 102, 74-78.
Gupta, V., Jain, R., Meena, M. L., & Dangayach, G. S. (2018). Six-sigma application in tire-manufacturing company: A case study. Journal of industrial engineering international, 14(3), 511-520. doi: http://dx.doi.org.contentproxy.phoenix.edu/10.1007/s40092-017-0234-6
Hamasaki, T., Kato, H., Kumagai, T., & Hagihara, A. (2017). Association between dentist-dental hygienist communication and dental treatment outcomes. Health communication, 32(3), 288–297. https://doi.org/10.1080/10410236.2016.1138376
Hamasaki, T., Kato, H., Kumagai, T., & Hagihara, A. (2017). Association between dentist-dental hygienist communication and dental treatment outcomes. Health communication, 32(3), 288–297. https://doi.org/10.1080/10410236.2016.1138376
Hamed Khawka, Z. (2016). Detecting Total Quality Management Status and Teamwork Orientation in Al-Yarmouk Teaching Hospital. American Journal of Industrial and Business Management, 06(03), pp.232-248.
Harel, Z., Silver, S., McQuillan, R., Weizman, A., Thomas, A., Chertow, G., Nesrallah, G., Chan, C. and Bell, C. (2016). How to Diagnose Solutions to a Quality of Care Problem. Clinical Journal of the American Society of Nephrology, 11(5), pp.901-907.
Harr, R. (2001). TQM in dental practice. International journal of health care quality assurance, 14(2), 69-81. doi: http://dx.doi.org/10.1108/09526860110386528
Improta, G., Cesarelli, M., Montuori, P., Santillo, L. and Triassi, M. (2017). Reducing the risk of healthcare-associated infections through Lean Six Sigma: The case of the medicine areas at the Federico II University Hospital in Naples (Italy). Journal of Evaluation in Clinical Practice, 24(2), pp.338-346.
Institute for Healthcare Improvement (2019). Pareto Chart. [online] Ihi.org. Available at: http://www.ihi.org/resources/Pages/Tools/ParetoDiagram.aspx [Accessed 29 Nov. 2019].
Institute for Healthcare Improvement (n.d.). Failure Modes and Effects Analysis (FMEA) Tool: Copy (2) of Access to Prosthetic Dental Services. [online] Available at: https://app.ihi.org/Workspace/tools/fmea/ProcessDetailDataReport.aspx?ToolId=6597&ScenarioId=7774&Type=1 [Accessed 29 Nov. 2019].
Johnson, R. (2015). Improving productivity and quality of a transformer production line by applying lean manufacturing principles (Order No. 1590110). Available from ProQuest Dissertations & Theses Global. (1693995703). Retrieved from https://search-proquest-com.contentproxy.phoenix.edu/docview/1693995703?accountid=35812
Johnson, R. B., & Christensen, L. (2019). Educational research: Quantitative, qualitative, and mixed approaches. Thousand Oaks, CA: Sage.
Jung-Lang, C. (2008). Implementing six-sigma via TQM improvement: An empirical study in Taiwan. TQM Journal, 20(3), 182-195. doi: http://dx.doi.org.contentproxy.phoenix.edu/10.1108/17542730810867218
Khoshnevisan, M., Dehghanian, D., Heydarpoor, P. and Attaran, N. (2019). Clinical governance in general dental practice. Journal of International Oral Health, 11(3), p.107.
Kirkire, M., Rane, S. and Jadhav, J. (2015). Risk management in medical product development process using traditional FMEA and fuzzy linguistic approach: a case study. Journal of Industrial Engineering International, 11(4), pp.595-611.
Kontonasaki, E., Rigos, A., Ilia, C. and Istantsos, T. (2019). Monolithic Zirconia: An Update to Current Knowledge. Optical Properties, Wear, and Clinical Performance. Dentistry Journal, 7(3), p.90.
Kourtis, S., Bachlava, E. and Roussou, V. (2016). Esthetic rehabilitation with zirconia-based shell crowns: a case report. International Journal of Dentistry and Oral Health, 2(4), pp.102-106.
Lameira, D., Silva, W., Silva, F. and De Souza, G. (2015). Fracture Strength of Aged Monolithic and Bilayer Zirconia-Based Crowns. BioMed Research International, 2015, pp.1-7.
Li, M., Huang, Z., Dong, T., Tang, C., Lyu, B. and Yuan, J. (2018). Surface quality of Zirconia (ZrO2) Parts in shear-thickening high-efficiency polishing. Procedia CIRP, 77, pp.143-146.
Li, M., Zhang, Y., Lu, Y., Yu, W., Nong, X. and Zhang, L. (2017). Factors influencing two-way referral between hospitals and the community in China: A system dynamics simulation model. SIMULATION, 94(9), pp.765-782.
Li, X., He, M. and Wang, H. (2017). Application of failure mode and effect analysis in managing catheter-related blood stream infection in intensive care unit. Medicine, 96(51), p.e9339.
Li, Z. Y., Bai, H. F., Wang, Y., & Sun, Y. C. (2018). Research status of tooth preparation quantitative guide technique. Zhonghua kou qiang yi xue za zhi= Zhonghua kouqiang yixue zazhi= Chinese journal of stomatology, 53(2), 137-140.
Liu, H., You, X., Tsung, F. and Ji, P. (2018). An improved approach for failure mode and effect analysis involving large group of experts: An application to the healthcare field. Quality Engineering, 30(4), pp.762-775.
Lutfiyya, M., Chang, L., McGrath, C., Dana, C. and Lipsky, M. (2019). The state of the science of interprofessional collaborative practice: A scoping review of the patient health-related outcomes-based literature published between 2010 and 2018. PLOS ONE, 14(6), p.e0218578.
Mark, M. & Reichardt, C. (2008). Quasi-experimental and correlational designs: methods for the real world when random assignment isn’t feasible. In C. SansoneC. Morf & A. Panter The SAGE handbook of methods in social psychology (pp. 265-286). Thousand Oaks, CA: SAGE Publications, Inc. doi: 10.4135/9781412976190.n12
Martín‐Ares, M., Barona‐Dorado, C., Guisado‐Moya, B., Martínez‐Rodríguez, N., Cortés‐Bretón‐Brinkmann, J., & Martínez‐González, J. M. (2016). Prosthetic hygiene and functional efficacy in completely edentulous patients: satisfaction and quality of life during a 5‐year follow‐up. Clinical oral implants research, 27(12), 1500-1505.
Meirowitz, A., Bitterman, Y., Levy, S., Mijiritsky, E., & Dolev, E. (2019). An in vitro evaluation of marginal fit zirconia crowns fabricated by a CAD-CAM dental laboratory and a milling center. BMC Oral Health, 19 doi: http://dx.doi.org/10.1186/s12903-019-0810-9
Mgbere, O., Singh, M. and Arafat, R. (2015). Measurement system analysis (MSA) of empirically derived composite measure of preventive care counseling practices of HIV medical care providers. International Journal of Medical Science and Public Health, 4(12), p.1640.
Mistry, K., Jaggers, J., Lodge, A., Alton, M., Mericle, J., Frush, K. and Meliones, J. (2019). Using Six Sigma® Methodology to Improve Handoff Communication in High-Risk Patients. [online] pp.1-11. Available at: https://www.ncbi.nlm.nih.gov/books/NBK43658/pdf/Bookshelf_NBK43658.pdf [Accessed 26 Nov. 2019].
Moccelini, B. S., De Alencar, N. A., Bolan, M., Magno, M. B., Maia, L. C., & Cardoso, M. (2018). Pulp necrosis and crown discoloration: a systematic review and meta‐analysis. International journal of paediatric dentistry, 28(5), 432-442.
Occupational Employment and Wages. (May 2018). Retrieved August 13, 2019, from https://www.bls.gov/oes/current/oes291021.htm#st
Ohno, T. (1988), Toyota Production System: Beyond Large-Scale Production, Productivity Press, Portland, OR.
Øilo, M., Schriwer, C., Flinn, B. and Gjerdet, N. (2019). Monolithic zirconia crowns – wall thickness, surface treatment and load at fracture. Biomaterial Investigations in Dentistry, 6(1), pp.13-22.
Özyemişci Cebeci, N. (2018). Factors Associated with Insufficient Removable Partial Denture Design Instructions. Dental and Medical Problems, 55(2), pp.173-177.
Pankaj Kumar, J. Maiti, Angappa Gunasekaran, (2018) “Impact of quality management systems on firm performance”, International journal of quality & reliability management, Vol. 35 Issue: 5, pp.1034-1059, https://doi.org/10.1108/IJQRM-02-2017-0030
Parry, G., Evans, J. and Cameron, A. (2014). Communicating Prosthetic Prescriptions from Dental Students to the Dental Laboratory: Is the Message Getting Through? Journal of Dental Education, 78(2), pp.1636-1642.
Prep Guide. (2019). [Photograph]. Retrieved from http://glidewelldental.com/wp-content/uploads/2016/02/all-ceramic-prep-guide.pdf
Pruitt, D. (2009). Experimental research on social conflict. In J. BercovitchV. Kremenyuk & I. W. Zartman the SAGE handbook of conflict resolution (pp. 102-118). London: SAGE Publications Ltd doi: 10.4135/9780857024701.n7
Rahman, A., Shaju, S. U. C., & Sarkar, S. K. (2018). Application of six sigma using define measure analysis improve control (DMAIC) methodology in garment sector. Independent journal of management & production, 9(3), 810-826. doi: http://dx.doi.org.contentproxy.phoenix.edu/10.14807/ijmp.v9i3.732
Raju, S., & Sowdaminit, T. (2015). Six sigma approach for productivity enhancement. Productivity, 56(2), 197-203. Retrieved from https://search-proquest-com.contentproxy.phoenix.edu/docview/1779946832?accountid=35812
Ridwan, A., Ekawati, R., & Novitasari, A. (2018). Quality control of the steel wire rod product by integration lean six sigma and taguchi method. MATEC Web of Conferences, 218, 4013. doi:10.1051/matecconf/201821804013
Salem, S., Al-Dossari, D., Al-Zaagi, I. and Qureshi, N. (2017). Lean Six Sigma, Root Cause Analysis to Enhance Patient Safety in Healthcare Organizations: A Narrative Review, 2000-2016. Journal of Advances in Medical and Pharmaceutical Sciences, 12(1), pp.1-26.
Schakaki, O. and Watson, A. (2017). A Study on the Effectiveness of Total Quality Management in Dental Patient Satisfaction. EC Dental Science, [online] 14(3), pp.114-149. Available at: https://www.ecronicon.com/ecde/pdf/ECDE-14-00481.pdf [Accessed 26 Nov. 2019].
Schmidt, A., Sousa-Zomer, T. T., Andrietta, J. M., & Cauchick-Miguel, P. A. (2018). Deploying six sigma practices to general electric subsidiaries in a developing economy: An empirical analysis. International journal of quality & reliability management, 35(2), 446-462. doi:10.1108/IJQRM-09-2016-0155
Schneebeli, E., Brägger, U., Scherrer, S. S., Keller, A., Wittneben, J. G., & Hicklin, S. P. (2017). Quality evaluation of zirconium dioxide frameworks produced in five dental laboratories from different countries. Journal of Prosthodontics, 26(5), 399-409.
Schriwer, C., Skjold, A., Gjerdet, N. and Øilo, M. (2017). Monolithic zirconia dental crowns. Internal fit, margin quality, fracture mode and load at fracture. Dental Materials, 33(9), pp.1012-1020.
Serdar PİRTİNİ. (2003). Communication related dimensions of TQM from the point of marketing and customer satisfaction view. Sosyal ekonomik araştırmalar dergisi, (6), 180. Retrieved from http://search.ebscohost.com/login.aspx?direct=true&AuthType=shib&db=edsdoj&AN=edsdoj.7c3aa22e79240f5a015419280f0825e&site=eds-live&scope=site
Sharma, P., Malik, S. C., Gupta, A., & Jha, P. C. (2018). A DMAIC six sigma approach to quality improvement in the anodizing stage of the amplifier production process. International journal of quality & reliability management, 35(9), 1868-1880. doi:10.1108/IJQRM-08-2017-0155
Shi, J., Li, X., Ni, J. and Zhu, Z. (2015). Clinical Evaluation and Patient Satisfaction of Single Zirconia-Based and High-Noble Alloy Porcelain-Fused-to-Metal Crowns in the Esthetic Area: A Retrospective Cohort Study. Journal of Prosthodontics, 25(7), pp.526-530.
Sippli, K., Rieger, M. and Huettig, F. (2017). GPs’ and dentists’ experiences and expectations of interprofessional collaboration: findings from a qualitative study in Germany. BMC Health Services Research, 17(1).
Skjold, A., Schriwer, C. and Øilo, M. (2018). Effect of margin design on fracture load of zirconia crowns. European Journal of Oral Sciences, 127(1), pp.89-96.
Snowdent, M., Ellwood, F., McSherry, R., Halsall, J. and Hough, D. (2017). Clinical Governance: A Friend or Foe to Dental Care Practice in the UK?. International Journal of Perceptions in Public Health, [online] 1(2), pp.112-120. Available at: https://core.ac.uk/download/pdf/81670978.pdf [Accessed 26 Nov. 2019].
Sogunro, O. A. (2002). Selecting a quantitative or qualitative research methodology: An experience. Educational research quarterly, 26(1), 3. Retrieved from https://search.proquest.com/docview/216183188?accountid=35812
Sunder, V. and Kunnath, N. (2019). Six Sigma to reduce claims processing errors in a healthcare payer firm. Production Planning & Control, pp.1-16.
Tadlaoui, K., Chafi, A. and Ennadi, A. (2018). The lean six sigma in a public hospital. Istrazivanja i projektovanja za privredu, 16(1), pp.60-69.
Timofe, M. and Albu, S. (2016). Quality Management in Dental Care: Patients’ Perspectives on Communication. A Qualitative Study. Medicine and Pharmacy Reports, 89(2), pp.287-292.
Tortorella, G., Augusto, B., França, S. and Sawhney, R. (2019). Assessment methodology for Lean Practices in healthcare organizations: case study in a Brazilian public hospital. Production, 29(0).
Tulbah, H., Alhamdan, E., Alqahtani, A., Alshahrani, A., & Alshaye, M. (2017). Quality of communication between dentists and dental laboratory technicians for fixed prosthodontics in Riyadh, Saudi Arabia. The Saudi dental journal, 29(3), 111-116. doi: 10.1016/j.sdentj.2017.05.002
von Scheel, H., von Rosing, M., Hove, M., Fonseca, M. and Foldager, U. (2015). Phase 2: Process Concept Evolution. The Complete Business Process Handbook, pp.11-35.
Walker, K. K., PhD., Jackson, R. D., D.M.D., & Maxwell, Lisa, LDH, B.S., M.S.N. (2016). The importance of developing communication skills: Perceptions of dental hygiene students. Journal of Dental Hygiene (Online), 90(5), 306-312. Retrieved from https://search.proquest.com/docview/1869508951?accountid=35812
Wang, G., Wang, C., & Qin, M. (2017). Pulp prognosis following conservative pulp treatment in teeth with complicated crown fractures—A retrospective study. Dental Traumatology, 33(4), 255-260.
Waylen, A. (2017). The importance of communication in dentistry. Dental Update, 44(8), pp.774-780.
Wilkinson, H., Whittington, R., Perry, L., & Eames, C. (2017). Does formulation of service users’ difficulties improve empathy in forensic mental health services. Journal of Forensic Psychology Research and Practice, 1-22.
Xue, Z., Li, H., Guan, R. and Chen, S. (2016). Applying healthcare failure mode and effect analysis to patient pain management in the anesthesia recovery period. Chinese Nursing Research, 3(1), pp.34-36.
Zhang, Y. and Kelly, J. (2017). Dental Ceramics for Restoration and Metal Veneering. Dental Clinics of North America, 61(4), pp.797-819.
Appendix A
Closed-ended Questionnaire for the Dentists
1. How was the Quality of overall cases?
a. acceptable b. excellent c. unacceptable
2. How long was the seating time?
a. Ideal b. too long c. unacceptably long
3. Did technician follow the Rx (written structure)?
a. yes b. no
4. How was the fit?
a. good b. tight c. loose
5. How was the occlusion?
a. good b. high c. Low
6. How were the contacts?
a. Good b. light c. open
7. How was the contour?
a. good b. over, c. under
8. How was the hade?
a. good b. dark, c. light
9. How was the anatomy?
a. good b. poor
10. How was the emergence profile?
a. good b. bulky c. under-contoured
11. How was the margin?
a. good b. open c. short
12. Did laboratory meet the Due date?
a. yes b. no
Appendix B
Figure1: Prep Guide for Metal-Free Restorations
AUTHOR BIOGRAPHY
[start section text here]
CORRELATION OF QUALITY OF ZIRCONIUM CROWNS, ADHERENCE TO PREP-GUIDE, AND EFFECTIVENESS OF DENTIST-TECHNICIAN COMMUNICATION: QUANTITATIVE CORRELATIONAL RESEARCH
by
Copyright 2019
A Dissertation Presented in Partial Fulfillment
of the Requirements for the Degree
Doctor of Business Administration
The Dissertation Committee for …… certifies approval of the following dissertation:
DISSERTATION
Committee:
, Committee Member
…………………., Committee Member
_________________________
_________________________
_________________________
_________________________
, PhD
Vice Provost, School of Advanced Studies
University of Phoenix
Date Approved: ___________
ABSTRACT
Start it here
DEDICATION
Start it from here
ACKNOWLEDGMENTS
Start it here
TABLE OF CONTENTS
Contents Page
List of Tables 24
List of Figures 25
Preface ix
Chapter 1: Title i
Introduction 1
Background of the Problem 4
Problem Statement 4
Purpose of the Study 6
Population and Sample 8
Significance of the Study 9
Nature of the Study 10
Research Questions/ Hypothesis 12
Theoretical Framework 16
Definition of Terms 17
Assumptions, Scope and Delimitations 17
Chapter Summary 19
Chapter 2: Title 21
Title Searches and Documentation 12
Communication and Quality Issues in Dental offices 12
Communication Between Dentists and ……………………25
History of Total Quality Management TQM, 30
Application of Six Sigma Tools 31
Application of LQMS 32
Current DMAIC Approach to Quality Improvement 16
Conceptual Framework Literature 34
Methodology Literature 34
Research Design Literature 35
Conclusions…. 37
Chapter Summary…. 38
References 40
Appendix A: Questinainre 47
Appendix B: Prep Guide 48
LIST OF TABLES
Table 1: Conceptual framework 7
Table 2: List of Dentists in Texas and Houston 2018 9
Table 3: Literature Keywords and the Resources …………………………………23
LIST OF FIGURES
Figure 1: Theoretical Framework 16
Figure 2: Title x
OTHER LISTS
Start here
PREFACE
[start section text here]
Chapter 1
Introduction
Dental technicians deal with quality issues due to the technological changes and ability to communicate with the team members and dentists. The technicians need to communicate with the dentists to produce desired products (Alshiddi, 2014). Communication in dental field is a challenging task because dentists work with a group of employees, including dental assistants, dental hygienist, and front desk staff (Alshiddi, 2014). Meanwhile, dental laboratory staffed with multiple technicians with different skills such as delivery staff, technical advisors, marketing, and human resources team. Communication between team members within the dental laboratory is a challenging task because communication must be done continuously and effectively.
Communication in dental business is an important component of business because the dental treatment requires teamwork. Dentists and the staff in the office must communicate constantly to provide a treatment. Dental offices work not only with the team in the office, but also with team in the dental laboratory to provide prosthetic services (Aboras, Muchtar, Azhari, & Yahaya, 2014). Dentists and technician must communicate in a daily basis if they want to improve the customer satisfaction and relationship that results in successful practices (Alshiddi, 2014). Quality issues become more problematic as dentist and technician fail to communicate which impacts the dental business negatively (Alshiddi, 2014). Lack of communication may be associated with quality issues, which are costly and time-consuming; thus, leading to customers’ dissatisfaction (Aboras et al., 2014).
Similarly, a manager in the dental laboratory must communicate with the staff to ensure that everyone has enough information to complete the task accordingly to the dentist’s written order. The communication occurs verbally and non-verbally through the emailing, written prescription, digital files, and face-to-face (Alshiddi, 2014). In this study, the researcher focuses on the only written communication between the technician and the dentist. Previous studies focused on the technicians’ abilities to follow the written guidelines provided by the dentists (Alshiddi, 2014). The researcher focuses on the dentists’ ability to follow up the laboratory’s prep-guide that presented in figure 1 (Bin-Shuwaish, 2017). Having a standard for the dentist helps to reduce the communication problems at the dental offices by clarifying the quality expectation from the dentists. The communication process in the dental laboratory occurs verbally between technicians and nonverbally between technicians and dentists. Having a written guideline helps to reduce the problem and improves the quality of communication between the dental office and the laboratory that lead to quality improvement. The researcher collects data from the dentists that request for zirconium crowns that require CAD/CAM procedure (computer-aided design/computer-aided manufacture) (Aboras et al., 2014). Creating high-quality dental products requires continuous and effective communication between the dental technicians and the dentists because information flows between dentist and technicians simultaneously. Reliable communication between dentist and technician correlated to the quality of prosthesis, satisfied clinicians, comfortable, professional relationship, and ultimately, successful practices in dental offices (Alshiddi, 2014).
There are three types of communication within the dental laboratory and dental offices, including Web Content Management System (WCMS), paper-based, and face-to-face communication (Alshiddi, 2014). The researcher in this study focuses on the paper-based communication and dentist compliance with specific prep guide that provided by the manufacturer of the CAD/CAM system. Figure 1 in Appendix B shows the example of the prep-guide that dentists use to prepare the tooth accordingly to reduce the natural tooth to comply with the CAD/CAM system (Prep Guide, 2019). Researcher send the questionnaire which is the instrument to the dentists that work with a dental laboratory (Crown World Dental Laboratory) for collecting data from dentists about their expert opinion about the quality of zirconium product. The prep-guide is the communication instrument that informs the dentist about the technicians’ expectations about the quality of dentist work. The researcher uses the independent variables, which is the prep-guide; and dependent variables listed in the questionnaire. ZrO2 restorations called zirconia (alloys like porcelain) possess high mechanical properties, but ZrO2-based restorations are subject to defects such as fracture, shade issues, and bonding to the abutments (Aboras et al., 2014). In summary, the researcher aims to find correlation strength between the independent variable (using the prep-guide) and the dependent variables (quality issues) listed in the questionnaire. Previous studies focused on communication between the dentist and the technicians through the dentists’ written structure, but this study focuses on the communication between technician and dentists through the prep-guide (Alshiddi, 2014).
Background of the Problem
Communicating continuously between dentist and technician leads to customer satisfaction and a better relationship that results in successful practices (Alshiddi, 2014). Having a broken communication between dentists and dental technician creates an opposite result that causes uncomfortable situation for the dentist and technicians (Alshiddi, 2014). Lack of communication between dentist and technician increases the production of the defected prosthesis (Alshiddi, 2014). Making a mistake in dental laboratories is a costly and time-consuming that leads to redoing the zirconium crowns and causing customers dissatisfaction (Aboras et al., 2014). Dentists become upset and uncomfortable with the defected works because of the cost of the chair-time and customer discomfort that may even lead to a lawsuit. Dentists blame the laboratories for not following the written instruction and laboratories blame the dentists for not following the prep-guide provided for the dentists. The problem becomes more complicated when dentists use unexperienced dental assistance to complete the process or using cheap material that reduces the accuracy of the final products.
Conversely, dental laboratories use unexperienced dental technicians to reduce the cost of operation in which leads to quality issues in dental laboratories. The problems escalate from miscommunication between the dentists and the dental technicians, but providing clear written structure helps to improve the quality of work in dental offices. The researcher aims to give insight on the relationship between quality and communication that impacts the customers’ satisfaction by focusing on the problem that comes from dentists because of not following the prep-guide (written communication) presented in figure1 (Prep Guide, 2019).
Problem Statement
The problem of the study is the unknown relationships between the efficiency of technician-dentist communication, adherence to prep-guide, and the different quality indicators of zirconium crowns. Poor quality of Zirconium crowns results in customer dissatisfaction (Martín‐Ares et al., 2016). Quality issues and customer dissatisfaction in dental business are the general issues that are correlated to the poor communication between the dentist and the technicians, and vice versa (Aboras et al., 2014). Production of a crown for a patient is a costly process that ultimately, the patient must pay for the operation. Dental offices and laboratories could reduce the cost of service by working together to mitigate procedural problems. Detecting the defected products in the early stage saves money for both the dental office and the dental laboratories (Schneebeli et al., 2017). The common reasons for failure in quality standards for crowns include discoloration, open-margins, fractures, and imprecise impressions (Moccelini et al., 2018; Wang, Wang, & Qin, 2017). Defected products cause lower profitability, a higher rate of capital cost, and lower brand image. Dentists are the ones that notice the flaws, but correction and remakes of the same crown cost time and money.
Two of the main factors considered for ensuring quality of zirconium crowns are ineffective adherence to the prep-guide and efficient communication between technicians and dentists (Apsari, 2017; Li, Bai, Wang, & Sun, 2018). Therefore, the quality problems related to zirconium crowns are linked to dental offices rather than dental laboratories because of not following the prep-guide, transferring information from the mouth to the cast (model-work) is a challenging task that depends on the dentist and his/her team ability to provide an accurate impression. A dentist should consider prep-guide for every single case; otherwise the treatment may fail because of dentist’s careless prep-work (Li et al., 2018). To further understand the relationship between technician-dentist communication, adherence to prep-guide, and quality of zirconium crowns, there is a need for a quantitative correlational study between efficiency of technician-dentist communication, adherence to prep-guide, and the different quality indicators of zirconium crowns.
Purpose of the Study
The purpose of this quantitative correlational study is to identify the significance of the relationships between the efficiency of technician-dentist communication, adherence to prep-guide, and the different quality indicators of zirconium crowns. The different quality indicators of zirconium crowns include overall quality, seating time, fitness, occlusion, contacts, contour, shade, anatomy, emergence profile, and margin. Based on the purpose of this study, the independent variables are efficiency of technician-dentist communication, and adherence to prep-guide. The dependent variables are the quality indicators of zirconium crowns. The questionnaire in Appendix A is the instrument for collecting data from dentists about their experiences about the quality of work. The goal is to provide insights to the dentists and technicians about the importance of the communication between staff and offices that helps the dental laboratories and dental offices to offer high-quality service and products to the customers. The researcher aims to evaluate quality issues by looking at the relationship between dentists that use the prep-guide and the ones that decide not to use the prep-guide. Table 1 and Table 2 show the dependent variables and independent variable.
Table 1
Definitions of Quality Indicators of Zirconium as Dependent Variables
Dependent variables Definition
Overall quality Overall quality determines the quality if the quality of crowns is acceptable, excellent, or unacceptable (Appendix A).
Seating time Seating time is the time that dentists spend to fit the crown in the mouth (Appendix A)
Rx followed Rx is the written structure (paper commination) that explains the dentist’s expectations (prescription) (Appendix A)
Fit Adapting the prosthetic edge to the abutment which is
the (prepped tooth) (Appendix A)
Occlusion Relationship between upper and lower jaws (Appendix A)
Contacts Contacts surface between adjacent teeth (Appendix A)
Contour Overall shape of the crown (Appendix A)
Shade Color of the crown that matches the natural tooth (Appendix A)
Anatomy Detailed feature of natural tooth (Appendix A)
Emergence profile Blending the crown from the side with the rest of the crowns
Margin Edge of the prosthesis crown (Appendix A)
Due date Appointment date that patient comes back to dental office
(Appendix A)
Table 2
Definitions of Independent Variables
Predictor variables Definition
Adherence to Prep-Guide A communication and training tool for the dentist to
prepare the tooth for the crown (Appendix A)
Effectiveness of Dentist-Technician Communication The level of proper understanding between technicians and dentists (Appendix A)
Population and Sample
The population of the study includes dentists in Houston, Texas. In 2018, the bureau of labor reported 8,110 active dentists in Texas, wherein 2,200 are in the Houston area, which comprise the target population of this study (Occupational employment and wages, May 2018). Table 3 shows the number of dentists in Texas and Houston reported by the United States Department of Labor (Occupational employment and wages, May 2018).
Samples will be obtained from the target population. The sample that will be chosen for this study is composed of dentists with dental offices in Houston Texas that work with the Crown World dental laboratories. Dentists in Houston area use the Crown World dental laboratory to order Zirconium crowns for the patients that need treatment for the decayed tooth. The sample was defined based on the requirements of addressing the purpose of the study.
Purposive sampling is a non-probability method to collect data from the sample when the resources are limited, so purposive method preferred to random sampling because participants are limited for this study (Etikan, Musa, & Alkassim, 2016). The purposive sampling is suitable for the purpose of the study because dentists that willing to follow the laboratory’s prep-guide is limited to the ones that work with the Crown World Dental laboratory.
To begin recruitment, the researcher will request permission from a dental organization with dental practice owners as members. The researcher will advertise the research with the organizational members by providing posters and flyers in the office of the organization. Interested members would be asked to contact the researcher to receive and sign an informed consent form. The informed consent form contains the details of the study purpose, intent for data collection, scope of participation, possible risks involved, and other rights and responsibilities of the participants of the study. The researcher will send the copies of the consent forms to interest participants. If the participant agrees with the contents of the consent form, he or she must sign the form and mail the signed copy to the researcher.
The sampling size that researcher aims to send the request form limited to about 150 dentists, so the sampling limited to the ones that agree to participate in the study by using the prep-guide. The goal is to assign each dentist to answer the survey. Using G*Power statistical software suggested that 134 participants based on a power of 0.95, the effect size of (0.30), and (α) error rate of (0.05). A two-tailed test was performed. Based on the rule of thumb, a power of 80% is the commonly used and accepted value for most studies (Cohen, 1988). However, for this study, a higher power was chosen because of the total population is 2,200. Moreover, a medium effect size of 0.30 will be used for this study, based on common practices for different quantitative power analysis performed to determine sample sizes (Gignac & Szodorai, 2016; Wilkinson, Whittington, Perry, & Eames, 2017). The level of significance is usually set at an alpha equal to a 5% level of significance, the typical standard for statistical significance. Figure 2 shows the result from G*Power software.
Table 3
List of Dentists in Texas and Houston 2018
Dental Specialties Number of Dentists in Texas
General dentists (Texas) 8,110
General dentists (Houston) 2,200
Oral and Maxillofacial Surgeons 460
Orthodontists 610
Figure 2. G*Power Analysis for sample size
Significance of the Study
The study could potentially benefit two sectors: dental industry leaders (e.g., dentists), and researchers in the academic field. Every single person that needs prosthesis from his/her dentist will benefit from this study because the factors that contribute to the quality of the dental crowns will be identified; thus, processes may be developed to improve the quality. Dentists, as leaders in the dental industry, dentists could benefit from this study. There are 2,200 dentists in Houston, Texas. These dentists may benefit from this study. The findings may be used as basis for additional information about the significance of the relationships between the efficiency of technician-dentist communication, adherence to prep-guide, and the different quality indicators of zirconium crowns. From this study, dentists may have basis for providing better services to their customers. Using written communication tool (prep-guide) may improve the quality of work that gives rise to the customer satisfaction. Using this information, dentists could have a basis for improving zirconium crown quality through prep-guide adherence and communication between technician and dentist. Through this study, the researcher can present empirically based findings that dentists may used for the improvement or development of procedures for improving zirconium crown quality.
The findings of the study may contribute to researchers in the academic field by addressing a literature gap in terms of the relationships between the efficiency of technician-dentist communication, adherence to prep-guide, and the different quality indicators of zirconium crowns. The findings of the study can also be used as basis for the topics and explorations in future research.
Nature of the Study
The nature of the study is an exploratory, quantitative with correlational research design to examine the relationship between quality and communication between dentists and technicians. The research method is quantitative, and the research design is correlational that researcher explains further in this section.
Research Method Appropriateness
A quantitative methodology is used when a researcher uses numerical data and tests hypotheses (Sogunro, 2002). Statistical analysis involved in the research and empirical research that data are in the form or numbers (Sogunro, 2002). The quantitative method is appropriate because the purpose of this quantitative correlational study is to identify the significance of the relationships between the efficiency of technician-dentist communication, adherence to prep-guide, and the different quality indicators of zirconium crowns. The participants are the dentists that participate in the research to provide feedback through the survey for every treatment and examining the association of the responses to the ones with no prep-guide. The researcher uses the data for correlation between the dentists’ compliance of the prep-guide (Appendix B) and quality issues mentioned within the questionnaire (Appendix A). The instrument is the survey with the closed-end questions that used by most of the laboratories to examine the quality of products. Therefore, the quantitative method will help to accomplish the research goals because the study requires passive interaction through the questionnaire, large population, before and after training, and availability of statistical package such as (SPSS) (Sogunro, 2002).
Conversely, qualitative method is not appropriate because researchers use the method to build a holistic picture formed with words (Sogunro, 2002). The qualitative method isn’t the right approach because the researcher cannot have an active interaction with the sample population (Sogunro, 2002). There is no need to have an ongoing observation and interviews, so the qualitative method should not consider for this study (Avgousti, 2013). Also, the qualitative method is appropriate for the ethnography and phenomenology because the purpose of the qualitative studies is to explore peoples’ behavior and interpret social realities (Avgousti, 2013).
Design Appropriateness
Correlational design is appropriate for the study because the purpose of the study is examining the strength of the relationship between the variables including independent variables (predictors) and dependent variables (criterion variables) (Pruitt, 2009). Studying the impact of an independent variable on another one with the correlational studies need no manipulation of variables as required by experimental studies (Pruitt, 2009). The correlational design is not appropriate for the treatment of causality; instead let the researcher directly to measure the variables (Pruitt, 2009). Correlational data must connect to specific distinct time to avoid the biased result, which can cause by the time lag between cause and effect (Pruitt, 2009).
A quasi-experimental design is another alternative for this study that helps to evaluate the cause and effect between the variables (Mark and Reichardt, 2008). Quasi-experimental design involves the comparison of variables linked to the time or different groups of individuals (Mark & Reichardt, 2008). Quasi-experiment and correlational designs can be used with the experimental designs to complement the findings and provide preliminary data for further studies (Mark and Reichardt, 2008). The correlational design preferred over quasi-experimental because the purpose of this quantitative correlational study is to identify the significance of the relationships between the efficiency of technician-dentist communication, adherence to prep-guide, and the different quality indicators of zirconium crowns.
Research Questions
This quantitative correlational study designed by the research question: What are the relationships between the efficiency of technician-dentist communication, adherence to prep-guide, and the different quality indicators of zirconium crowns? The question designed to examine the association between usage of pre-guide by dentists and zirconium quality issues. The three hypotheses that intended to answer the research question are listed below.
Hypothesis
The listed null and alternative hypothesis designed to answer the research question, and the researcher tests the correlation coefficient to examine the correlational strength for each null hypothesis. Further examination will implement by determining the relationship between variables, which may be positive or negative. Also, the Pareto chart will be used to classify the quality issues based on the frequency.
H10: There is no significant relationship between adherence to prep-guide and the overall quality of zirconium crowns.
H1A: There is significant relationship between adherence to prep-guide and the overall quality of zirconium crowns.
H20: There is no significant relationship between efficiency of technician-dentist communication and the overall quality of zirconium crowns.
H2A: There is a significant relationship between prep-guide and the overall quality of zirconium crowns.
H30: There is no significant relationship between adherence to prep-guide and efficiency of technician-dentist communication.
H3A: There is a significant relationship between adherence to prep-guide and efficiency of technician-dentist communication.
Theoretical Framework
The theoretical frameworks that set the foundation of this study is situated cognition theory (Brown, Collins, & Duguid, 1897). Situated cognition is a learning theory that refers to learning from experience and social interactions (Brown et al., 1989). For instance, Brown et al. (1989) believed that learning is a social experience and individuals are able to learn when they interact with others, communicate, problem solve and share knowledge with each other. For example, dentists could learn how to improve quality of zirconium crowns through interaction and communication with technicians.
Definition of Terms
Prep means a tooth that prepped by the dentist for prosthetic treatment.
Remake means redoing the cases because of technical failures.
Crown is fabrication of missing part of any tooth with zirconium materials.
Margin is the border between the prepped tooth and the rest of the tooth toward the root.
CAD/CAM stands for (computer-aided design) and (computer-aided manufacture).
TQM is the total quality management including Six-Sigma, and Define, Measure, Analyze, Improve, and Control (DMAIC) that takes total employees’ involvement to approaches to complete the cycle of process management (Jung-Lang, 2008). TQM technique involves activities for quality management, including Plan, Do, Check, Action (PDCA) that builds the concept of continuous improvement daily (Jung-Lang, 2008).
Just in Time (JIT) is the creation of efficiency and reduction of overhead that increases return on investment (ROI), and elimination of the unnecessary work-in-process to ensure a continuous flow of products (Ohno, 1988)
Lean is the philosophy applied to the process of any business to improve productivity and to eliminate non-value activities and reduce the lead-time to deliver products to customers (Johnson, 2015).
Assumptions, Scope and Delimitations
There are four assumptions in the study of the association between communication and quality issues among the dentists and technicians that lead to quality improvement and customer satisfaction. The first assumption is that a significant relationship exists between dentists’ ability to follow the prep-guide and quality improvement. There is an assumption that prep-guide (written-communication) is a great tool to allow the technician to communicate with the dentist, which lead to customer satisfaction. Next, the researcher believes that participants (dentists) provide information about their experiences sincerely to provide data about the quality of zirconium crowns. The researcher assumes that participants are credible and trustworthy, and their information purely helps the study to provide information about the research question. Finally, the researcher believes that the findings may not be generalizable because of purposive sampling and limiting the investigation to the dentists that work with the Crown World Dental laboratory. The questionnaire must send to the dentists that were already working with the company, so the limitation of the sampling may become a barrier for the generalizability of the findings. Conversely, G*Power calculation suggested 134 participants that will be enough to produce generalizable results.
The scope of the research limited to the dental laboratories and dental offices that use CAD/CAM system, and the study is essential for the whole industry because CAD/CAM system dominated the industry. The scope of the study requires dentists with the ability of to providing an acceptable prep, which is time-consuming and costly for the offices. Evaluating the strength of correlation between variables may improve the validity and reliability issues due to external sampling issues. The quality issues vary among the dental office because of the business model and type of services that may impact the dentist’s ability to contribute to the study.
There are general issues that limit the validity and reliability of the instruments, such as participants’ intention. Participants may find themselves uncomfortable to share sensitive information and provide inaccurate information about their experiences. Submitting information about the quality of the products may not represent the larger population or situation that impacts all dental offices. Measuring the correlation strength between the quality of products and each criterion variable may become challenging if participants avoid participating fully before reaching the saturation level.
The study’s delimitation managed by considering only the participants (dentists) that work with the Crown World Dental Laboratory in Houston. The study delimited by using the sample size that suggested by G* Power software (134 participants), in which reduces the rate of type I and type II errors and improves the possibility of generalizability. Research questions limited to closed-end questions that provided through the questionnaire listed in Appendix A. The research question examines the strength of the relationship between usage of prep-guide and quality improvement that recorded int the survey (Appendix A).
Chapter Summary
The purpose of this quantitative correlational study is to identify the significance of the relationships between the efficiency of technician-dentist communication, adherence to prep-guide, and the different quality indicators of zirconium crowns. Dental treatment is a costly procedure because staff in the dental offices and dental laboratories work as a team to provide dental services to their patients including the zirconium crowns. The researcher aims to evaluate the correlational strength between the predictor (usage of prep-guide) and criterion variables (quality issues). Dentists are the target population, and sampling size depends on the availability of the dentists that willing to participate in the study. The research question focuses on the relationship between quality of zirconium crowns and dentists’ compliances of the prep- guide. The scope of the study narrows down to the available dentists that already deal with the quality issues. Dentists should have enough time to finish their work, and not all dentists will be available in the same time, so the researcher needs at least three months to collect the data from enough participants that willing to participate in the study.
The assumption is that participants join the study eventually and provide their unbiased suggestion based on the final products. The researcher uses the closed-end questionnaire to conduct quantitative research that offers correlational insight about the quality issues and the written communication (prep-guide). The researcher focuses on communication issues between the dentists and technicians, which is the research gap and essential for the quality improvement in dental offices. There are three hypotheses for the study. Quantitative methodology and correlational design are appropriate because of the nature of the study that requires statistical analysis. Chapter two begins with the introduction to literature review and articles that provide secondary information about relationship between dentists and technicians, quality issues in dental laboratories, communication in medical field, and quality assurance practices, such as the six sigma, total quality management (TQM), quality improvement, Just in Time (JIT) quality control.
Chapter 2
Literature Review
In this section, the researcher focuses on the literatures that provide information about the quality management and communication between the dental offices and dental laboratories. The literature review consists of the articles such that the dental technicians’ compliances of written structures by the dentist (Alshiddi, 2014). Literatures about the quality management of different products in sectors such as tire and garment company that used lean six-sigma to determine the problems and find solutions for the issues. Subjects about the total quality management (TQM) techniques, such as Six-sigma, are used among managers for the purpose of the quality control (Schmidt, Sousa-Zomer, Andrietta, & Cauchick-Miguel, 2018). DMAIC stands for defining, measuring, analyzing, improving and controlling in which is a methodology to map out the problems and solution for the high rate of the defects in the dental laboratories (Sharma et al., 2018).
The purpose of this quantitative correlational study is to identify the significance of the relationships between the efficiency of technician-dentist communication, adherence to prep-guide, and the different quality indicators of zirconium crowns. The researcher focuses on the previous studies that examined the poor-quality-works in the production lines, such as a tire, wire rod, and garments. The companies used the six-sigma to find solutions to improve the quality of the products in a different sector. The researcher compares the methodology and design of the studies to discover similarity and difference with the undertaken research. The research question addresses the problem related to the dentists’ compliances of the prep-guide and association with the quality issues. Germinal data collected from the University of Phoenix database that associated with total quality management (TQM), quality improvement, and just in time (JIT), quality issues in a dental office, and communication issues in dental and medical offices. The articles are scholarly, and peer-reviewed that provide germinal information about the topic and research purposes.
Title Searches and Documentation
The literature and information obtained from scholarly journals, textbooks, and official websites. The academic and scholarly peer-reviewed publication that related to the TQM in business and communication in dental industry accessed from EBSCOhost, ProQuest. The leading search engine was the Google Scholar and Google website that used to retrieve peer-reviewed literature about the topics during the last ten years. Information about the communication between dental offices and laboratories accessed from the Internet database such as Dissertation and Thesis, ProQuest, and Sage at the University of Phoenix website.
The scholarly document accessed from the University of Phoenix library and google scholars by using keywords including, communication between dentist and technician, quality issues in dental laboratories, quality issues in dental office, communication in medical field, sample size estimation, total quality management (TQM), quality issues with zirconium crowns, Six-Sigma, just in time (JIT), LQMS, SIPOC, MSA, FMEA, Pareto Chart, DPMO, DPU, and PPM. Table 4 shows a summary of the literature that retrieved from the University of Phoenix and the Internet database search engine such as Google Scholars.
Table 4
Literature Keywords and the Resources
Area of the research Peer-reviewed articles/Journals Scholarly books Doctoral Dissertation
Communication 6
Quality management 17 1
Research method and design 3 2
Sample size 1
Teamwork 3
Customer satisfaction 4
Communication Issues among Professionals in the Dental Field
Bin-Shuwaish (2017) suggested that compliances with the dentists’ written guidelines help the quality of work to improve and reduces the defect in dental laboratories. The findings of the study indicated that the research needs more longitudinal analysis and collecting more data from more extensive range dental laboratories (Bin-Shuwaish, 2017). The study provided insight into the regular communication between the dentists and the dental laboratories, but the conversation just focused on the dental laboratories. The study has a lack of information about the importance of mutual communication between laboratories and dental offices. I consider the importance of dentist’ ability to provide a classic impression that let the technicians to transfers the data from mouth to a cast (model-work). The researcher aims to address the research gap by considering dentists’ compliances of dental laboratories guideline.
Limited research existed about defect rates of zirconium crowns and quality management that promotes using of six-sigma in the organizations that show cause and effects relationships (Schmidt, Sousa-Zomer, Andrietta, & Cauchick-Miguel, 2018). Dental laboratories are not the exception, and another business avoids using the six-sigma to conduct the quality of their production. Studies about the six-sigma cover issues related to customer satisfaction and defect management process and DMAIC process.
Why Dentists Change Laboratories
Dentists work with their labs for three reasons, including quality, excellent communication, and reasonable pricing (Burns, 2013). There is about %49 percent of the dentists that change their laboratory because of communication issues that stop the dentist from building a long-term relationship (Burns, 2013). Dentists are looking for advice from the laboratory regarding the shade, impression-taking techniques, restoration, and material choices (Burns, 2013). Dentists express their concern and switch their lab if there is no solution to the problem (Burns, 2013). The study indicates that communication is an essential factor that creates a long-term relationship or causes dissatisfaction because of poor quality produced by the dentist and the technician. Dentists quiet their labs because of quality issues and studying quality issues that related to the communication between dental laboratory and dentists helps to build a good relationship between team members in the dental offices (Burns, 2013).
Communication Between Dentists and Dental Technicians
Tulbah, Alhamdan, Alqahtani, Alshahrani, Alshaye, (2017) explored issues related to the communication between dentist practitioners and the dental technicians about the authorization and selection of the trays and materials. The study suggested that clear communication is a critical factor that improves the quality of fabricated fixed and removable prosthesis (Tulbah et al., 2017). The researchers contributed a questionnaire among the dental technicians that concerned with the quality of written instruction from dentists (Tulbah et al., 2017). The findings indicated that only half of the written instructions were clear, and the rest needed farther communication between dental technician and the dentist to produce quality-work (Tulbah et al., 2017). The study indicates that communication between dental technicians and dentists is a critical factor for the success of the final products. The communication is essential, but it must happen mutually rather than just dentists provide a written guideline. Having dentists to follow up with the dental laboratory’s’ prep guide helps to improve the quality of the dental products, which is the goal of the researcher in the study.
Overall, the role of quality communication has been widely examined in previous research. In this study, however, only a few studies were included for critical analysis. The researcher included only studies that were published in the last five years (2014-2019). It is also worth noting that Tulbah et al. (2017) is a Saudi Arabian study. Another related study that was published within the last five years is Sudanese as it was conducted at the capital of Sudan, Khartoum. The researcher paid little attention to critically analyze the Sudanese study because the findings were less relevant and contributive to the present study. Particularly, the research explored communication between dentists and dental lab technicians whereby they indicated that the quality of communication was low (Arbab Ali, Khalifa and Nasser Alhajj, 2018). Nevertheless, the authors of the study did not indicate its impact on the quality of dental services.
Furthermore, the findings of Tulbah et al. (2017) and Arbab Ali (2018) were reaffirmed by another Saudi Arabian study that investigated the compliance of dental lab technicians to the written instructions by dentists whereby the findings revealed that commercial labs performed better than government labs (Bin-Shuwaish, 2017). The authors further indicated that this phenomenon explains the quality differences between commercial labs and government labs. Therefore, the theory that was formed from the findings of this study aligns with other theories that have been originated in other studies like that of Tulbah et al. (2017).
Therefore, the main literature gap that could be identified concerning this sub-topic is that there is insufficient literature of prior research examining the various factors that affect the quality of communication between the dentist and dental lab technicians. However, the few studies available have suggested that the quality of communication affects general service quality significantly. From an action research perspective, it is therefore imperative to also examine the various factors that affect the quality of communication to initiate potential solutions to the problem. Nonetheless, there is a general notion that the mode of communication can affect various aspects of quality communication such as timely message delivery and so on. Some of these modes have been highlighted in the previous section of this report. For instance, Parry, Evans and Cameron (2014) discovered that only 15% of dental lab technicians complied with written prosthetic prescriptions by dental students, an indication that handwritten work authorization could be a less effective communication tool in this setting. Therefore, it is also significant to evaluate the effectiveness of various communication means such as handwritten work authorization and website content management system (WCMS).
Communication with the Handwritten Work Authorization vs WCMS
Communication between the dentist and the technician happens through the handwritten work authorization, but digital advancement led to the electronic communication between the dentist and the technician. Alshiddi (2014) explored issues related to communication methods such as web content management system (WCMS) and paper communication methods to improve the communication quality due to the fast Internet connection that allows faster upload and download than usual. The researcher suggested that WCMS helps the dentist to communicate more quickly and effectively with the technician that lead to quality improvement (Alshiddi, 2014). Web content management is available for the dental offices to communicate with the partners, but the privacy issues become a severe problem for the dental offices (Alshiddi, 2014). The author claims that paperless communication saves money and time for the dental offices; thus, eventually becoming mandatory in some countries (Alshiddi, 2014). Considering the paperless communication is a perfect choice for many offices, but the elimination of paper communication may not be possible for every office. Working with the CAD/CAM system provide an opportunity for the dentist and technician to communicate digitally, but communication between the technician and the dentist may become challenging. In a dental laboratory, technicians work together to produce dental products, while communicating with every single technician becomes very challenging. The dentist may request any orders and demand for the desired outcome, but the technician cannot claim for change because the dentist already does the job. Quality of work by dentist impacts the quality of dental products and technician may not be able to request for a change because of costly chair-time in the dental office. Considering the cost of late communication, the technician should communicate in advance with the dentist to reduce the possibility of mistakes in the dental office. Asking the dentist to use the prep-guide is the best way to create a pro-active communication with the dentists that help to reduce the mistakes done in the dental office.
The findings of Alshiddi (2014) were confirmed by another study by Bin-Shuwaish (2017) which investigated the compliance of dental lab technicians to written instructions by dentists. The findings of the study indicated that compliance was considerably determined by many factors including the type of communication between dentists and dental lab technicians. The study discovered that paper-based communication was the least effective among other forms of communication such as web-based, personal, verbal, and photographic. These observations were also reflected by another study by Özyemişci Cebeci (2018) which investigated factors influencing low-quality instructions for removing partial denture design. The author insinuated that paper-based communication is not only expensive but also the least effective among other forms of communication such as telephone call, text messaging, email, and web-based communication. Therefore, low-quality instructions are commonly associated with paper-based communication hence the need to embrace web-based communication than paper-based communication.
Moreover, the issue of paper-based communication has been associated with other aspects of poor communication in the context of dental practice. For example, in their study, Alammari and Albagar (2018) investigated the quality of written communication between senior dentist students and dental lab technicians. The findings of the study indicated that senior dentist students communicate poorly, and this phenomenon was connected to the communication techniques that they learned during their clinical education. Predominantly, the findings indicated that most students learned paper-based communication techniques during their clinical education, and this extended to their poor communication with dental lab technicians. Nevertheless, Gaylor (2016) hinted that a combination of both paper-based and web-based communication techniques in a dental setting improves the overall quality of communication. Though the author did not provide sufficient reasons for this observation, the researcher of the present study connected the phenomenon with improved data privacy, cost, and fast transfer of information. Chiefly, prior studies have indicated that the use of pure web-based communication between dentists and dental lab technicians is cost-effective and timely, but it poses major challenges to data privacy. Also, paper-based communication could be more confidential than web-based communication. Hence, the combination of the two improves the efficiency of communication by observing all aspects (such as cost, timeliness, and data privacy) in a single package. Furthermore, the researcher of the current study supposed that, if the purpose of combining paper-based and web-based communication is to promote data privacy while observing cost and timeliness, then it is also possible to replace paper-based communication from the duo with other more effective forms of communication like text messaging, e-mail, and telephone call. For instance, text messaging can help in observing data privacy because the communication is directly between the sender and the receiver without the involvement of third parties. Since scholars like Özyemişci Cebeci (2018) have observed that these forms of communication are more effective than paper-based communication, then it is recommendable to perform the proposed substitution. Overall, web-based communication is superior to paper-based combination hence the need for minimal utilization of the latter.
The Importance of Developing Communication Skills
Dental hygienists are major team players in dental offices and have to communicate with dentists and the patients. Developing communication skill of the hygienist is correlated to their ability to perceive effective communication, understand barriers, and ability to use personal communication tools (Walker, Jackson, & Maxwell, 2016). The researchers contributed six open-ended questions to two broad classes of the first- and second-year hygienists’ students at Indiana University to collect data about their perception of effective communication, barriers they encountered, and emerging technology (Walker et al., 2016). The gap mentioned in this study linked to the emerging technology that future studies may focus on and find solutions for the communication issues among the team members in the medical field (Walker et al., 2016).
Nevertheless, the findings of Walker et al. (2016) have confirmed that communication in any healthcare setting including dentistry is very challenging. This observation was also avowed by numerous other studies such as Alammari and Albagar (2018) which indicated that the kind of communication taking place between dentists and dental technicians is generally poor in multiple settings. In a study (Waylen, 2017) that investigated the importance of effective communication in dentistry, it was discovered that communication in this setting is challenging because it is both a clinical and complex skill that pertains to direct patient care and constituent skills. Waylen (2017) further observed that effective communication between dentists and dental technicians promotes a good relationship not only between them but also with other team players like hygienists. Effective communications also promote respect between professionals and facilitate improved patient care. Therefore, the researcher of the present study observes that collaborative learning in dentistry would help in alleviating communication problems between dentists and technicians. In this way, dental students will learn both constituent and clinical communication skills in an integrated manner resulting in better results. These observations are consistent with the literature in other healthcare settings such as nursing – for instance, El-Sayed and Ahmed Mousa (2015) discovered that cooperative learning improves the development of communication skills among psychiatric nursing students. Therefore, one of the possible solutions to improving communication between dentists and dental lab technicians is to introduce cooperative or collaborative learning in teaching communication skills among dentistry students. Currently, this is a literature gap hence the need to confirm these observations in the future through the use of empirical means.
Quality of Zirconia
During the recent years, demand for the zirconium crows increased due to the durability and natural-looking results in which CAD/CAM system allows to produce the zirconium products (Meirowitz, Bitterman, Levy, Mijiritsky, & Dolev, 2019). The open- margin is the critical issues that dental offices face and having a defect in the margin is a severe problem (Meirowitz et al., 2019). The researchers examined two available CAD/CAM systems, including CEREC and LAVA, to explore issues related to margin, and there was no significant difference between the two systems. The study of zirconium quality limited to the margins within the two systems and researcher never mentioned about the role of the dentist in quality issues. The problem with this is study is that the researchers assumed that the dentist does not make a mistake, which is not valid in reality. Considering the role of the dentist in quality issues lead my study to examine the relationship between dentist compliances with the dental laboratory requirements through the written communication tools such as prep guide.
In another related study, it was determined that the type of material used in manufacturing monolithic zirconia dental crowns affects the quality of the margins (Schriwer et al., 2017). The study investigated the quality of the margins in six different types of dental zirconia crowns whereby the quality of the margins was assessed by using light microscopy in an ordinal scale. The findings of the study revealed that the quality of margins was statistically different between the six different commercially available crowns. However, unlike Meirowitz et al. (2019) who discovered that production method does not impact on the quality of margins, Schriwer et al. (2017) concluded that production method and the zirconia material used affects the quality of margins. Additionally, this study discovered that there was a statistically significant correlation between fracture load and the quality of margins. This discovery was also confirmed by another study by Skjold, Schriwer and Øilo (2018) which investigated the factors influencing the fracture (survival) of zirconium-based restorations where it was revealed that margin design is one of them. Other factors, in addition to material selection, manufacturing type, and margin design, that have been implied in the literature include balancing tooth size and shape, surface state, tooth contact conditions, residual stresses, and tooth structure (Zhang and Kelly, 2017). Communication plays a major role in ensuring the balancing of these factors to produce the most desired zirconium-based restorations. However, no study has investigated the correlation between the quality of communication and some of these factors, which is a significant literature gap that the present study pursues to fill. Additionally, it was observed that many studies have investigated surface quality of zirconium-based restorations.
Studies that have investigated the surface quality of zirconium-based restorations have implied a connection between surface quality and fracture load. For instance, in their study, Li et al. (2018) discovered that the type of manufacturing affects the quality of the surface of zirconium-based restorations which in turn affects their fracture load. This finding was confirmed by another study by Lameira et al. (2015) which indicated that monolithic and bi-layer zirconium restorations portray different levels of fracture strength. Lameira et al. (2015) exposed the two types of crowns to artificial ageing whereby it was revealed that monolithic crowns have a higher level of fracture strength than bi-layer zirconium restorations. This study concluded that surface finishing and design has an impact on the fracture strength of zirconium crowns. Moreover, monolithic zirconium restorations have different surface designs namely thick-walled and thin walled. In a study, it was discovered that thin-walled crowns are less resistant to fractures than thick-walled crowns (Øilo et al., 2019). Overall, these studies have indicated that there are numerous factors affecting the quality of zirconium-based restorations and proper communication between the dentists and dental lab technicians is crucial in meeting all of them. Studies like Shi et al. (2015) have discovered that the quality of crowns affects patient satisfaction profoundly hence the need for adherence to proper communication. Indeed, in a case report study, it was concluded that proper communication is key to the clinical achievement of high-quality crowns for improved patient satisfaction (Kourtis, Bachlava and Roussou, 2016).
Shade Issues
The shade is another issue that dentist and technician face since patients want natural-looking tooth that matches with the adjacent teeth (Alomari & Chadwick, 2011). Using different shade tab to decide on the shade causes confusion and problem for the technician and the dentist (Alomari & Chadwick, 2011). Vita shade tab is the classic shade tab that dentist use to match with the natural tooth and ask through the written prescription to duplicate the shade, but sometimes dentists use different shade tabs which are different than the one that laboratory uses (Alomari & Chadwick, 2011). Shade tab is a communication tool between the dentist and technician that let the technician take the necessary steps to duplicate the crowns (Alomari & Chadwick, 2011). The study suggested that communication between dentist and technician is essential, and lack of communication impacts the quality of work in dental offices.
Shade issues have been studied extensively in the literature. Since lack of communication affects the quality of work, especially shading issues, it is also imperative to examine some of the issues that are likely to be relevant to the communication aspect. In their study, Ahangari et al. (2015) discovered that different shading techniques namely staining with brush and submerging in coloring liquid have different effects on the value of zirconium crowns. The study particularly discovered that the submerging technique is better than staining with a brush. However, the appropriateness of technique is based on specific customer requirements hence implying that poor communication might result in the use of an inappropriate shading technique.
This observation has also been confirmed by other scholars. For instance, Tulbah et al. (2017) indicated that a dentist should indicate the type of shade needed in the written authorization. However, about 75% of their participants reported that they received a specification of shade type from dentists, which indicates poor utilization of communication to promote patient satisfaction provided that the colour of the shade is a preference of the patient. These findings were also affirmed by Arbab Ali et al. (2018) whereby about 44% of their participants indicated that they did not receive specific shade type to be used. Since Ahangari et al. (2015) indicated that the technique used in shading zirconium crowns affects their quality, Arbab Ali et al. (2018) and Tulbah et al. (2017) confirmed the significance of communication between the dentist and dental technician. The importance of communication in this context was also reiterated by Eakle and Hatrick (2015). However, unlike the other studies, Eakle and Hatrick (2015) indicated why it is significant for dental technicians to help dentists choose the most appropriate shade to prevent unnecessary frustrations related to additional lab fees in case an inappropriate shade is chosen. Therefore, in case there is a statistically significant correlation between the quality of zirconium crowns and communication, the findings of these studies have revealed the mechanism involved. If the correlation is not statistically significant, then it shall be confirmed that the fact that Ahangari et al. (2015) did not imply the role of dentists in their study affected the conclusions of the researcher regarding this subject.
Factors Affecting Dental Quality
Quality in dental offices affects patients’ satisfaction and depends on factors, such as: communication, responsiveness, reliability, waiting time, admission process, satisfaction, and technical competence (Bahadori, Raadabadi, Ravangard, & Baldacchino, 2015). The study of total dental quality management received the least attention among the other professions and fluctuation of quality lead to the dissatisfaction among the dental patient (Bahadori et al., 2015). Responsiveness was one of the major factors that influence to customer satisfaction when a patient needed multiple treatments, but staff unwillingness to provide the best the services led to the wasting patients’ time, money, and energy (Bahadori et al., 2015). Reliability is another essential factor that the researchers mentioned that impacts the customer satisfaction and helps to improve the quality of work by reducing the waiting time and cost of operation (Bahadori et al., 2015). The researchers emphasized the role of poor communication that impacts the quality issues in dental business and causes customers’ dissatisfaction (Bahadori et al., 2015). The study suggested that the quality of work depends on many factors, especially poor communication, are associated to the quality of work in dental offices (Bahadori et al., 2015). The researchers suggested that improving the quality in dental offices requires the attention of staff to every patient’s need responsiveness is the key to improve customer satisfaction (Bahadori et al., 2015).
Bahadori et al. (2015) are one of the few researchers that have investigated the significance of communication between the dentist and other professionals in the dental office and revealed the mechanism of involvement. When the author performed an advanced search strategy on Google Scholar, no other study was retrieved concerning the importance of interprofessional communication in the dental office. However, studies examining interprofessional communication between dentists and other healthcare professionals such as medical doctors, nurses, and pharmacists have been published in the past. For instance, Lutfiyya et al. (2019) investigated the impact of healthcare collaborative practice in various patient outcomes such as satisfaction and cost of care. The findings of the systematic review of the literature discovered that collaborative practice, which is characteristic of interprofessional communication, reduces the cost of care and improves patient satisfaction. This finding insinuated that communication between dentists and dental technicians could improve various patient outcomes in the dental office. Overall, although many scholars like Lutfiyya et al. (2019) advocate that collaborative practice is part of healthcare reform in countries like the United States, many others have also acknowledged that there is limited research in this area. For instance, in their study, Sippli, Rieger and Huettig (2017) indicated that there is limited research on the interprofessional collaboration expectations between dentists and general practitioners. Similarly, the researcher of the present study discovered that there is limited research on how communication between the dentist and the dental technician could influence the quality of zirconium crowns and the overall quality of service delivery at the dental office. Therefore, the current study aims to fill this literature gap by exploiting the correlation between the quality of zirconium crowns, the effectiveness of communication between the dentists and dental technicians, and adherence to prep guide.
Quality Assurance Practices
Total Quality Management in Dental Practices
Dental laboratory managers implement total quality management (TQM) by determining the goal and objectives, control the cost, availability of the documents and instructor in the practice, and determining lack of the standards (Harr, 2001). The TQM in dental business subdivided to three sections of “structural quality” (quality for services, infrastructure, and training), “process quality” (quality of treatment process), and “outcome quality” (quality of the treatment outcome) (Harr, 2001, p.4). The outcome quality is the aim of this study by exploring the correlation between a dentist’s compliance with the prep-guide and the quality issues listed in the questionnaire. The treatment process is vital for the study because dentists must follow the guideline and provide necessary means that a technician can use to produce the zirconium crown.
Additionally, many studies have investigated TQM in various contexts of dental practice with significant implications in the context of communication between the dentist and dental technician. For example, Khoshnevisan et al. (2019) emphasized that interprofessional communication and other professional issues in dental practice could be solved through continuous professional development by means of mentorship. Khoshnevisan et al. (2019) made this recommendation in the context of clinical governance as a prime strategy for continuous improvement through the best standards of dental care. Nevertheless, in their systematic review of the literature, Snowdent et al. (2017) discovered that the application of clinical governance into dental practice is limited in the United Kingdom due to lack of knowledge and confidence by practitioners in its application and evaluation. The study concluded that there is a need to conduct more research in the future to instill confidence in practitioners because clinical governance is a viable framework for improving the quality of care in dental practice as a vital component of TQM. Since communication is one of the determinants of patient satisfaction in any clinical setting, it is imperative to examine its correlation with adherence to prep-guide and quality of zirconium crowns. This observation is reaffirmed by another UK study which discovered that there is a strong connection between TQM and patient satisfaction (Schakaki and Watson, 2017). Therefore, patient satisfaction is the moderating factor in the connection between TQM and interprofessional communication. However, this connection has not been explored in the literature. Thus, future research should also focus on testing this hypothesis because it is a significant gap in the literature that could help in advancing the findings of the present study. Therefore, one of the avenues of implementing TQM to a dental office to enhance communication between the dentist and dental technician among other professionals is introduction of clinical governance. Since it is currently challenging to execute clinical governance into dental practice, it is also prudent to evaluate the history of TQM and other strategies from the outset to lay a firm groundwork for future research.
History of TQM, Six-Sigma, and Just in Time (JIT)
Quality managers use Total Quality Management (TQM) since the 1980s and six-sigma came later as a new tool to improve the quality at workplaces such as GE and Motorola (Schmidt, Sousa-Zomer, Andrietta, & Cauchick-Miguel, 2018). TQM uses part per million defectives (ppm) and yield to measure the rate of defects and assess the quality then react to the problem (Jung-Lang, 2008). TQM used by quality managers through the plan, do check, and action to reduce the rate of the defect (Jung-Lang, 2008). Six-sigma used by quality managers to reduce the frequency of the deficiency by using DMAIC methodology to tackle undesirable activities that cause a defect. For example, quality managers of the factors that make steel wire rods used Six Sigma methodology to improve the quality towards the target of 3.4 failures per million opportunities (DPMO) (Ridwan, Ekawati, and Novitasari, 2018). Just in time is another TQM methodology that reduces the waste in an organization. Toyota used JIT to manage supply, production, and performance for many years in which made the customers happy and satisfied (Danese, Romano, and Bortolotti, 2012). JIT used to reduce the production time and eliminate practices that cost money and produces no value for the customers (Danese et al., 2012). JIT is a useful method to reduce the defect rate of products because managers improve the quality of inventory by lowering the cost of overstock. Managers use JIT by measuring factors such as unit cost of manufacturing, inventory turnover, on-time delivery, and fast delivery (Danese et al., 2012).
Presently, Six Sigma is widely used in various fields of practice including dentistry. However, there is limited research on how the Six Sigma methodology could be used to improve the communication between the dentist and other professionals like dental technicians. However, some studies have implied that the use of Six Sigma could help in improving the overall quality of care in dental settings. For instance, Akifuddin (2015) discovered that the utilization of Six Sigma Methodology helps in a significant reduction of complications of local anesthesia in dental healthcare setups thus demonstrating improved quality of care and patient satisfaction. In other healthcare settings, the Six Sigma methodology has shown remarkable effectiveness in reducing care related costs (Sunder and Kunnath, 2019). It has also been associated with improved handoff communication (Mistry et al., 2019). Overall, the findings of this literature review have revealed that the application of Six Sigma methodology in dentistry is currently limited due to lack of knowledge. However, the findings of the few studies that have been cited have indicated that Six Sigma could be a potential quality management approach in dental settings due to improved communication between professionals, reduction of cost, and ultimate improvement of patient satisfaction.
Nevertheless, the JIT industry is widely used in the manufacturing industry (von Scheel et al., 2015). It could also be used in manufacturing high-quality zirconium crowns. However, when the researcher performed an advanced search on Google Scholar to identify studies that have examined its effectiveness in dentistry, none was retrieved. This observation insinuates limited literature on this topic hence the need for future studies to examine the potential application of JIT in dental care. Overall, TQM is the commonly used approach followed by Six Sigma. JIT has little or no application in the present time. Therefore, it is imperative to examine the communication dimensions related to TQM since it is the most commonly utilized in dental care settings.
Communication Dimension Related of TQM
TQM philosophy focuses on fulfillment of customer requirement for every single time with no exception and improving the quality of work continuously (Serdar Pirtini, 2003). Quality should build in the process of production rather than inspecting the process regularly to ensure that quality meets the customer requirements (Serdar Pirtini, 2003). TQM benefits from communication process by creating two-way communication wherein customer requirement is identified in a systematic way (Serdar Pirtini, 2003). The implementation of TQM in an organization depends on the team able to communicate proactively instead of reactive communication (Serdar Pirtini, 2003). In TQM, communication means interaction for a common goal and sharing encoded knowledge, feeling, and thoughts that promote quality vision in an organization (Serdar Pirtini, 2003).
Overall, many studies on quality control and management in dental care have implied that communication is one of the most crucial aspects that affect the quality of dental services, which also comprises the quality of zirconium crowns. For example, in their systematic review that examined various quality management measures in primary dental care, Byrne et al. (2018) mentioned the theme of communication repeatedly. For instance, they indicated that the quality of communication between dentists and patients affects patient satisfaction. However, Byrne et al. (2018) did not examine TQM as they focused on other quality control measures such as the use of patient questionnaires to survey the quality of communication and information provided. The essence of quality communication between patients and dentists was also implied in another study that was conducted by Timofe and Albu (2016). Most studies have focused on the communication between the dentist and the patient with little emphasis on interprofessional communication such as between dentists and dental lab technicians. However, in whichever way, numerous scholars have indicated that effective communication and care coordination leads to improved quality care in the dental office. For instance, Dental Quality Alliance (2019) indicated that effective communication among other elements of quality dental care affects customer experience leading to either improved customer satisfaction. The observations of the Dental Quality Alliance (DQA) (2019) are in alignment with the objectives of this study considering that TQM was mentioned as the commonly used quality management strategy in dental practice. Similarly, in another study, it was discovered that TQM is positively correlated with teamwork in healthcare settings including dentistry (Hamed Khawka, 2016). Also, Waylen (2017) indicated that one of the benefits of effective communication in dental practice is the enhancement of teamwork. Therefore, the main point of connection between communication dimensions and TQM is teamwork, which has also been associated with improved quality care in healthcare settings including dentistry. The findings of these studies have, therefore, hinted that communication is an important aspect of quality management in dental practice, especially in the production of high-quality zirconium crowns. However, the main observation made from these studies is that there is no study has examined this phenomenon directly in dentistry, especially in the context of effective communication between the dentist and the dental lab technician. Thus, the present study is the first one to fill this literature gap. Also, since Six Sigma is the second most commonly used quality management in dental care, it is also important to examine it further to determine how it reduces the cost of poor quality in dental practice.
Application of Six Sigma Tools and Reduction of Cost of Poor Quality (COPQ)
Managers used the Six-Sigma (DMAIC) methodology in companies such as helicopter component manufacturing to reduce the rate of the defect (Anupama, 2014). Helicopter cooling components are critical because if something goes wrong, the pilot may not survive. Managers used the primary statistical tools to examine the failure of cooling fan assembly at repair division of a company for the helicopter components. Combination of technique that reduces the cost of repair and rework is another practical approach that help the managers not only to reduce the defect rate of products, but also minimize the cost of poor quality and (COPQ) (Anupama, 2014). The goal to use the Six-Sigma is to stop the defects before they appear and reduce the COPQ by adopting a predictive rather a reactive approach toward rejection and rework (Anupama, 2014).
Moreover, in the previous section, it was determined that the use of Six Sigma in healthcare, especially in dentistry is rare but it has been approved to be effective. This observation was affirmed by numerous prior studies. For instance, Antony et al. (2018) discovered that Lean Six Sigma is effective in healthcare, but its focus has been the whole hospital rather than specific departments such as dentistry. This conclusion aligns with how Ahmed (2019) and Tadlaoui, Chafi and Ennadi (2018) approached their research study that was investigating how Six Sigma methodology could be applied in healthcare. Both Ahmed (2019) and Tadlaoui et al. (2018) particularly focused on the whole healthcare system (hospital) with little emphasis on specific departments. The findings of the two studies revealed that Six Sigma methodology could help in improving quality towards patient satisfaction by reducing costs, errors, and defects. Additionally, Salem et al. (2017) implied that in addition to these benefits, the application of Six Sigma in healthcare also improves the work performance of healthcare professionals thus improving the efficiency of healthcare delivery. Applied directly into the context of the present study, these findings imply that if the Six Sigma Methodology is applied in dental practice, especially in the communication between the dentist and dental lab technicians, it could help in reducing costs and errors of producing zirconium crowns. In the previous sections, it was also determined that, for instance, poor communication between the dentist and the dental lab technician can lead to increased costs related to replacing poorly produced or defective crowns that do not meet customer preferences. However, the most crucial aspect is its applicability in specific departments of the healthcare system. If possible, the application of Six Sigma in hospitals can be modelled into smaller settings such as in departments without cost increment. Therefore, the main observation regarding the applicability of Six Sigma in healthcare settings is that no study has examined how it could be used in specific contexts such as dentistry. Future research should aim to fill this gap in the literature to advance research on this area towards achieving better patient satisfaction in healthcare. Therefore, it is important to evaluate the other various methodologies of Six Sigma such as SIPOC and DPMO other than DMAIC to determine the one that could best apply in dentistry.
Application of LQMS, SIPOC, MSA, FMEA, Pareto Chart, DPMO, DPU, and PPM
Managers use six-sigma SIPOC to define the problem, which stands for suppliers, input, process, output, and customers (Sharma, Malik, Gupta, & Jha, 2018). Indian managers used DMAIC to reduce the process variation in the anodizing stage of the amplifier (Sharma et al., 2018). SIPOC is an analysis tool that helps to examine the process of production from suppliers to customers. In the context of overall healthcare whereby dental care is encompassed, DMAIC is the commonly used type of Six Sigma methodology than SIPOC (Al-Qatawneh, Abdallah and Zalloum, 2019). When the researcher performed both a basic and advanced search on Google Scholar using keywords such as Six Sigma, SIPOC, dental care, and zirconium production, no single relevant result was produced, an indication of insufficient literature in this area of interest. However, a hand search for articles that used Six Sigma to improve quality in various healthcare contexts yielded some articles that demonstrated how SIPOC could be used in healthcare. For instance, in their study, Alkinaidri and Alsulami (2018) demonstrated that SIPOC could be used in improving the quality of a referral system in a hospital. Particularly, the scholars indicated that SIPOC helps ensure seamless referral request processing: the process involves receiving a referral request, a consultation process, and finally returning the referral to the requester. Since the dental room is a specialized unit, it receives referral requests from other units of the healthcare system. The quality of processing the referral request matters in healthcare because, according to Li et al. (2017), an effective referral system helps in optimizing resource utilization and distribution in healthcare.
In the context of dental care, SIPOC could be used in improving the effectiveness and efficiency of referral processing thus leading to optimal healthcare delivery with limited resource availability. However, since no study has tested the effectiveness of SIPOC in the setting of dental care, future research should focus on this subject to provide adequate evidence. It is also worth noting that SIPOC cannot be used independently but rather in combination with DMAIC. For example, in their study, Alkinaidri and Alsulami (2018) indicated that SIPOC can be used to achieve the above objectives during the “Define Phase” of DMAIC. This observation was also reiterated in another study that was conducted by Improta et al. (2017) investigating how to improve the quality of infection control measures in hospitals. Improta et al. (2017) indicated that the SIPOC analysis is crucial in the Define Phase of DMAIC. Nevertheless, none of these studies has implied any communication dimensions in this type of Six Sigma methodology. Therefore, future research should also focus on how SIPOC could be applied in the context of improving communication between the dentist and the dental lab technician since it affects the overall quality of dental care including the production of high-quality zirconium crowns. In other words, if DMAIC could be applied in the control and management of the quality of zirconium crowns, scholars should investigate how SIPOC could be integrated into the Define Phase of DMAIC to improve the communication between the dentist and the dental technician.
Pareto chart is another analysis tool that allows the researcher to priorities the defects from the least to the most that happens in the production line. For example, the Pareto analysis produced Pareto chart for the anodizing stage of amplifier and defects classified as pitting (69.45%) and the rest of the errors were due to the total of (33.55%) streaking and crazing defects (Sharma et al., 2018). In healthcare, Pareto analysis has also been widely adopted. For instance, Harel et al. (2016) used Pareto analysis to identify problems that contribute to reduced quality of care. The graph shown in Figure 1 below presents a histogram of the most significant causes of the quality of care problem. The identified causes might be less relevant to the topic under investigation, but the graph has simplified the application of Pareto analysis in the healthcare system. In the United States, the application of Pareto analysis in healthcare was proposed by the Institute for Healthcare Improvement (IHI) whereby it was indicated that it is useful in helping practitioners to concentrate their efforts on the most significant factors thus leading to appropriate addressing of a particular problem (IHI, 2019). In the United Kingdom, the Pareto chart is also commonly used in NHS. For instance, in the East London NHS Foundation Trust, the Pareto chart is used in determining how often particular events or incidents take place in healthcare delivery (East London NHS Foundation Trust, 2019). The Trust follows the 80 ⁄ 20 principle whereby it is assumed that in most cases, roughly 80% of the effects come from 20% of the causes. Therefore, the focus of the improvement efforts should be diverted towards solving the 20% causes to alleviate the 80% effects.
In the production of zirconium crowns, the Pareto chart can help in analyzing the most significant factors influencing the quality of zirconia crowns and the overall quality of dental care. Many factors have been mentioned among them improper handling of the materials, the effectiveness of communication between the dentist and the dental lab technician, among others (Cionca, Hashim and Mombelli, 2016). Little is known about the most significant causes of poor-quality zirconium crowns hence the need for Pareto analysis. Despite the wide application of Pareto analysis in healthcare, little to no research has been conducted to evaluate its effectiveness in dental care, hence a significant literature gap that needs to be filled in future research. For instance, the current study might indicate that the effectiveness of communication between the dentist and the dental lab technician might affect the quality of zirconium crowns and adherence to pre-guide in a statistically significant manner. However, within the limitations of this study, it does not expose the significance level of ineffective communication as a problem affecting the quality of zirconium crowns in a given dental care setting. Nevertheless, it is also apparent that in a specific dental care setting, ineffective communication between the dentist and the dental lab technician is not the only problem facing the production of quality zirconium crowns. Therefore, in the overall improvement in the production line, all these problems need to be listed and their significance levels are determined by the use of Pareto analysis. If the analysis determines that ineffective communication and lack of adherence to prep guide are the most significant problems facing the production of high-quality, then the dental room needs to unleash corresponding efforts to eliminate or reduce them.
Figure 3: A histogram indicating the most significant causes of the quality of care problem as discovered in the study of Harel et al. (2016).
Lean quality management system (LQMS) approaches to problems by reducing the waste, just-in-time (elimination of unnecessary work in process), continuous improvement, perfect quality, optimization, visual management, and human resource engagement (Bacoup, Michel, Habchi & Pralus, 2018). Using LQMS helps companies to obtain certificates if the companies receive no complaint about over two years (Bacoup et al., 2018). Lean management originated in Toyota to eliminate the wastes and cut the steps with no values for the customers. Lean tools are simple in comparison to the six-sigma tool that managers use them with statistical methods (Bacoup et al., 2018).
Moreover, Lean tools are also used in healthcare organizations. Though, there is limited literature on how Lean tools can be used successfully to improve the overall quality of service delivery in healthcare. A few studies have been published indicating how the Lean process might be useful in reducing waste in healthcare organizations. For instance, Tortorella et al. (2019) formulated an evaluation process for ensuring successful implementation of the Lean process to healthcare organizations. The researchers were motivated by the fact that most healthcare organizations experience significant challenges in implementing Lean processes hence the need for a validated evaluation process during the implementation phase.
Indeed, no study has investigated how the Lean process could be helpful in dental care. Probably, ineffective communication between the dentist and dental lab technician carries elements of replication of processes leading to resource wastage and overall customer dissatisfaction. In such a case, the Lean process can help in removing unnecessary steps in the communication between dentist and dental technician thus leading to improved effectiveness. Due to lacking scientific evidence, this is also a significant literature gap. Besides, Carey et al. (2018) indicated that Lean tools are also used in microbiology laboratories to eliminate waste or remove processes that do not add value to the product. It begins with an evaluation process to identify repeat works, high inventory, delays, and so on. If it has been effectively applied in microbiology labs, its application can also be replicated in dental labs with a little bit contextualization to align with the specific operations of the dental lab. Also, Fagerlind Ståhl et al. (2015) discovered that the effective use of Lean tools in organizations adds their competitive value and promotes optimal utilization of limited resources. In most healthcare systems around the world, optimal utilization of limited resources without compromising patient satisfaction and quality of care is highly encouraged. Even in dental care, according to Tulbah et al. (2017), the use of limited resources to produce high-quality zirconium crowns is highly encouraged. Therefore, Lean tools can be useful in enhancing the communication between the dentist and the dental lab technicians as well as improving the quality of zirconium crowns. However, due to missing scientific evidence, this is a significant literature gap. Future studies should focus to fill it by formulating conceptual frameworks that permit the successful application of Lean into dental care settings.
Also, the Six-sigma is a measuring tool and measuring system analysis (MSA) and analysis tools such as Pareto analysis that is a useful tool to help to detect quality issues. In healthcare, the MSA system has been implemented in a wide variety of contexts. In their study, Mgbere, Singh and Arafat (2015) discovered that successful implementation of MSA in HIV preventive care services leads to a reduction in measurement variations thus resulting in improved work performance output and eventual improvement in the quality of preventive care services and overall patient outcomes. Also, Furterer and Hernandez (2019) indicated that MSA has been widely used in healthcare to assess the accuracy and use of equipment and devices. The researchers further observed that MSA could be used in assessing the accuracy of a human element in a healthcare diagnosis service process. Since diagnosis service processes take place nearly in all healthcare departments including dentistry, it can be said that MSA can successfully be used to improve the accuracy of human elements as well as equipment and devices. Particularly, in the context of dental care and specifically the communication between the dentist and dental technicians, human elements, as well as devices and equipment, are involved frequently. MSA could help in assessing their accuracy to deliberate the need for improvement using other quality control and management tools such as Lean and Six Sigma. Up to this point, it is also apparent that quality management tools are unique in the quality improvement process. Thus, to yield optimal results for quality, a combination of these tools is mandatory thus demonstrating further the complexities involved in quality management in healthcare organizations. These complications make it extremely challenging to implement these tools in specific departments like dentistry perhaps due to cost of implementation and the high levels of expertise needed. The next paragraph presents how another tool process called FMEA can be combined with these other tools to improve the overall quality of care in healthcare organizations.
Improving quality is the final goal and using process failure mode, and effects analysis (FMEA) focuses on factors such as men, methods, material, machinery, measurement, and environment. Controlling is another step that managers use a control chart to suggest changes that monitor the changes that improve the quality of products. FMEA is one of the most extensively used Six Sigma tool in health care. In a systematic review, it was discovered that most scholars recommend the use of FMEA in healthcare by considering it a useful and effective tool (Dastjerdi et al., 2016). Indeed, many studies like Liu et al. (2018) have evaluated its application in various contexts of healthcare. For instance, Li, He and Wang (2017) evaluated how FMEA can be used to improve the management of catheter-related bloodstream infection in ICU. The authors concluded that FMEA can reduce incidences of a blood infection in this setting, improve the quality of nursing, reduce medical expenses, and improve the security of central nervous catheterization (Li et al., 2017). Xue et al. (2016) also discovered that FMEA can help in improving pain management and improve the quality of nursing care in the anesthesia recovery period.
Also, unlike most of Six Sigma methodologies that have been discussed before, FMEA is the only methodology that has been applied in dental contexts in multiple times in prior research. For instance, Kirkire, Rane and Jadhav (2015) proposed a model for risk mitigation during dental product manufacturing to minimize failures using the FMEA methodology. The findings of the study concluded that FMEA is effective in avoiding the duplication of processes and improves the conversion of expert cognition into information to get values of risk factors. This conversion involves improved effectiveness of interprofessional communication. For example, dentists possess the expertise of how zirconium crowns should be designed to meet customer demands whereas dental technicians possess the expertise of executing the plan of the dentist. Therefore, FMEA methodology could also be narrowed down and be applied in the context of improving the effectiveness of communication between the dentist and the dental technician. However, the significance of a future study that replicates the methodology that was used by Kirkire et al. (2018) to determine of FMEA could be used to improve communication will rely upon the findings of the present study. Particularly, if the current research discovers that there is a strong correlation between the quality of zirconium crowns and the effectiveness of communication between the dentist and the dental technician, then future research will hold a lot of significance in dental practice.
Likewise, other studies have proved that FMEA´s application in dental practice is diverse. For instance, Akifuddin (2015) discovered that FMEA is effective in reducing complications of local anesthesia in dental healthcare setups through improved quality of management. Reduction in health complications is generally associated with lower medical costs. Also, the United States´ Institute for Healthcare Improvement (IHI) (n.d.) indicated that this methodology can be used by government policy formulators to improve access to prosthetic dental services. Overall, FMEA holds potential in improving the quality of zirconium crowns. Hence, future studies should focus on drafting a conceptual framework through which it can be used effectively in this context.
Nonetheless, the Six-Sigma concept aims to keep the defect levels below 3.4 defectives per million opportunities (DPMO) (Raju and Sowdaminit, 2015). Quality control managers use six-sigma to reduce defects, and the goal is to increase the sigma value from toward Six Sigma, which is an indication of the lowest possible error (3.4 per million) (Raju and Sowdaminit, 2015). In the context of manufacturing zirconium crowns, it was highlighted in the previous sections that the occurrence of defects during the different procedures of manufacturing affects the chipping of veneering porcelain on zirconia-based ceramic frameworks. Therefore, controlling the number of defect occurrences per million opportunities during the manufacturing of zirconium crowns is crucial to maintaining high-quality standards (Kontonasaki et al., 2019). The main advantage of DPMO is that it can be converted into sigma metric and vice versa thus making the overall Six Sigma methodology highly effective both in industry and business (Coskun, Serteser and Ünsal, 2018). If the manufacturing of zirconium crowns utilizes the Six Sigma methodology, all data need to be converted into DPMO and then focus on the phase where more defectives occur. In this way, occasioning risk mitigation becomes less challenging resulting in the overall improvement of the quality of zirconium products. Additionally, other defect indicators are defects part per million (PPM) and defect per units (DPU) used by the lean managers to calculate the defect rate of manufacturing products.
Current DMAIC Approach to Quality Improvement
General Electric (GE) used the six-sigma program in Brazil to improve issues such as a market share on a global scale (Schmidt et al., 2018). Using six-sigma is not limited to any business, and quality managers use it to improve the quality of produces. The Indian company that provides anodized amplifiers is one of the companies that took the initiative by using DMAIC process of six-sigma to enhance the quality of their products and reduce process variation (Sharma, Malik, Gupta, & Jha, 2018).
Conceptual Framework Literature
A conceptual framework comprised of ideas that provides structure to a theory in a research to guide the study and find connections between different concepts (Dziak, 2018). Interpersonal communication (two-way communication) is the conceptual foundation for the study (Serdar PİRTİNİ, 2003). Germinal studies of interpersonal communication and TQM find in studies of the Serdar PİRTİNİ (2003) that included the concept of interpersonal communication with the total quality management (TQM). The process of interpersonal communication studied by Shannon and Weaver’s model of communication (1949) which in the basic format that comprised of sender, the message, the channel, the receiver, and the noise as an additional component (Min, Koo, & DeLong, 2015). The most important part of the Shannon and Weaver’s models is the feedback that comes from the customers and help to improve the quality of services and products with a two-way communication (Min et al., 2015). The correlational study of quality and communication depend on the feedback that comes from dentists about the quality of work.
The study of interpersonal communication will be based on factors such numerical, feedback, privacy, goal, and mutual influence (Long & Vaughan, 2007). Interpersonal communication depends on the number of people, medium used for the communication, interaction in privacy or public, and tasks that influences others (Long & Vaughan, 2007). The major dimensions of communication vary from human-human, human-machine, and human-society (Serdar PİRTİNİ, 2003). Human-to-human communication is the focus of the study and conceptual framework provides guidance to analyze the relationship between quality and communication in dental offices.
Methodology Literature
The research methodology used in the different articles and documents included in this review are either qualitative or quantitative. In most cases, the reports about the different qualitative assurance practices, such as TQM, Six Sigma are mostly used for general references. Therefore, no specific quantitative procedure was used to present the information in the different document sources. For the discussion of the importance of communication and the different quality aspects of dental crowns, most studies are quantitative in nature. For this study, the methodology will be quantitative because the focus of the purpose, research questions, and hypotheses of the study is the relationship between independent variables (e.g., efficiency of technician-dentist communication, adherence to prep-guide) and dependent variable (e.g., overall quality of zirconium crowns).
Dentist, Hygienist, and Dental Treatment Outcome
Cooperation between dentist band the team within the dental office is an essential fact that impacts the quality of treatment (Hamasaki, Kato, Kumagai, & Hagihara, 2017). Dental hygienists are a critical team player in dental office and quality of service and products depend on their technical ability (Hamasaki et al., 2017). Dentist and hygienist must work together to serve the patients, but miscommunication between them can cause serious problem for the office. The correlational study of communication between hygienist suggested that there is a significant correlation between interprofessional communication and patients’ satisfaction (Hamasaki et al., 2017). The method used to determine the association between communication and patient satisfaction by giving questionnaires to the patients (total 250), and dentists and hygienist complete the rest of the survey separately (Hamasaki et al., 2017). A five-point Likert scale implemented to measure the satisfaction from very insufficient to very sufficient (Hamasaki et al., 2017). One-way analysis of variance (ANOVA) used to examine the patients’ satisfaction based on the dentist and hygienist perceptions (Hamasaki et al., 2017). A multiple regression analysis used to evaluate the factors affecting the patient satisfaction (patient, hygienist, and dentist), and PASW® Version 18 used for statistical analysis (Hamasaki et al., 2017). Using a quantitative method with correlational orientation helps to examine communication and quality issues in dental offices, which depend on secure communication between the team members.
Research Design Literature
The literature in this section provides scholarly knowledge about the research design the help to obtain the proper plan for the study. The primary goal of the literature is to provide insight into the correlational research design that helps to determine the relationship between compliances of the prep-guide by dentists and quality improvement in dental laboratories. The research design is quantitative non-experimental correlational. Questionnaire is the instrument to collect the data.
A non-experimental approach involves an uncontrolled setting wherein variables are measured as they occur (Johnson & Christensen, 2019). For this study, the researcher will use a non-experimental design because it is more appropriate to address the research questions of the study. An experimental design was not appropriate for this study as the focus was to identify the relationships of the variables without manipulating the data. Moreover, a correlational design is used in researches when the researcher needs to explore the extent or the strength of the relationship between the independent and dependent variables. Based on the purpose of the study, the independent variables (e.g., efficiency of technician-dentist communication, adherence to prep-guide) and dependent variable (e.g., overall quality of zirconium crowns).
Conclusions
The literature review contributes knowledge about the interconnectivity of the communication and quality improvement in which dentists and technicians must communicate continuously and mutually. Methodology and history of quality control in different companies, especially dental laboratories reveal that managers need to work the team members and keep everyone up to date to improve the overall customer satisfaction. Researcher explores articles that concentrate on TQM and techniques such as the Six-Sigma methodology and DMAIC process to explore possible solution to improve the quality of products in dental office. The purpose of this quantitative correlational study is to identify the significance of the relationships between the efficiency of technician-dentist communication, adherence to prep-guide, and the different quality indicators of zirconium crowns. The literatures presented information about the users of Six-Sigma that aimed to reduce the defect rate in the production line. The researcher explores the literature that presents quality control issues and possible solutions that help to improve the quality of the products.
Chapter Summary
The literature review related to studies that already covered the importance of the dental technicians’ compliances of dentists written guidelines on the prescriptions. The literature review provided insight into the TQM and techniques such as six-sigma and DMAIC methodology and SIPOC process used by major companies such as GE, Motorola, and Toyota. The previous studies introduced TQM techniques to improve quality in manufacturing sectors. The previous studies used methodologies such as cost of poor quality (COPQ) and just in time (JIT) techniques to reduce the waste and activities that increase operational cost. These studies help the researcher define the problem and help the dental business to consider prep-guide and protocols that help to improve the quality of dental products. In conclusion, researcher goal is to explore the TQM and using Pareto chart to classify the issues in dental business and examine the relationship between communication and the quality issues listed in the questionnaire.
Concepts that introduced in the literature review includes lean quality management system (LQMS) that managers use to reducing the waste with continuous improvement (Bacoup, Michel, Habchi & Pralus, 2018). Using DMAIC is a process of Six-Sigma to enhance the quality of products that reduce waste (Sharma, Malik, Gupta, & Jha, 2018). SIPOC is another concept used among managers in TQM to define the problem, which stands for suppliers, input, process, output, and customers (Sharma, Malik, Gupta, & Jha, 2018). TQM philosophy focuses on customer satisfaction for every single time with no exception, and quality should build in the process of production (Serdar PİRTİNİ, 2003). Communication is the center of study in this study that impacts the quality issues in a dental office, so considering the hygienist ability to perceive effective communication and barriers examined in the literature review (Walker, Jackson, & Maxwell, 2016). The literature review covered the subject of patients’ satisfaction and factors such as responsiveness, waiting time, and admission process (Bahadori, Raadabadi, Ravangard, & Baldacchino, 2015). Communication methods such as web content management system (WCMS) and paper communication methods addressed in the study due to the advancement of technology. Finally, the researcher explored reasons such as quality, excellent communication, and reasonable pricing that improves the relationship between dentists and technicians (Burns, 2013).
Chapter 3
Methodology
The purpose of the study is to find relationship between the efficiency of technician-dentist communication, adherence to prep-guide as a communication tool, and quality of zirconium crowns. The goal is to find the relationship between adherence to prep-guide and quality issues such as shade, shape, fit, overall quality, contacts, and seating time. A quantitative methodology and correlational research design applied to the study to examine the effectiveness of dentist-technician communication and the relationship between quality of zirconium crowns and understanding between technicians and dentists.
The discussion in previous chapter explored the scholarly articles related to communication and quality issues in dental filed and manufacturing. Articles provides data about the relationship between the adherence to prep-guide and quality of zirconium crowns and efficiency of technician-dentist communication. The chapter 3 provides methodology that implemented to examine the relationship between the adherent to prep-guide, efficiency of technician-dentist communication, and quality of zirconium crowns. The chapter provide data about the population, sampling, consent information, validity and reliability. Data collection procedure and instrumentation are the focus of the study which follows with the data analysis and summary of the chapter.
Research Methodology and Design Appropriateness
A quantitative method introduced in chapter 1 to examine the association between dentist adherence to prep-guide, technician-dentist efficiency of communication, and quality of zirconium crowns. The quantitative method suggested to collect and analyze data to answer the research question. Three hypotheses presented in chapter 1 that suggests relationship between adherence to prep-guide, efficiency of technician-dentist communication with the quality of zirconium crowns. The correlation design suggested to examine the relationship between adherence to prep-guide, efficiency of technician-dentist communication and zirconium quality issues.
Research Method Appropriateness
A quantitative method talks in terms of change in variables (mathematics) or relationships among sets of variables (regression). In quantitative research, we want our theories and findings to have verisimilitude, and the extent to which we can make a case that our theories and findings have verisimilitude is the bottom line in quantitative communication science BAILEY, K. (2007).
Quantitative research involves variables. Variables are symbols to which numerals or numbers are assigned. Variables are also observable things that vary or that can take on different values. In this sense, variables are contrasted with both constants and constructs. Constants are things whose values are fixed; they do not vary (Levine, 2009).
Variables can be related to each other in a variety of different ways. Given that the goal of quantitative communication research is usually to document and explain how variables are related, knowing about different types of relationships between variables is essential.
One possibility is that no relationship exists. That is, the variables are completely unrelated, and there is no covari-ance. (Levine, 2009).
Levine, T. (2009). Quantitative approaches to communication research. In W. F. Eadie 21st century communication: A reference handbook (Vol. 2, pp. 57-64). Thousand Oaks, CA: SAGE Publications, Inc. doi: 10.4135/9781412964005.n
BAILEY, K. (2007). Quantitative methodology. In C. D. Bryant & D. L. Peck 21st century sociology (Vol. 2, pp. I-108-I-117). Thousand Oaks, CA: SAGE Publications, Inc. doi: 10.4135/9781412939645.n10
Design Appropriateness
In statistics, correlation is more specifically defined as a measure of the strength, or consistency, of the linear relationship between two variables in a population. Graphically, this statistic indicates how well the scatterplot obtained by representing the observations on a Cartesian plane with the two variables as dimensions fits along a straight line. Correlation is most commonly measured—or estimated, when only a sample is available—with the Pearson product-moment coefficient (ρ or r in statistical notation, respectively, for populations and samples), a standardized indicator whose value ranges between -1 (perfect negative correlation) and 1 (perfect positive correlation), and where 0 denotes the absence of correlation. correlation can be positive if the variables move in the same direction (they both increase or decrease at the same time), or negative if they move in opposite directions (when one variable increases, the other decreases). (Kurian, 2011).
A set of statistical techniques for measuring the extent to which two variables are related. For interval-scale data, the strength of relationships can be expressed quantitatively by using a correlation coefficient such as the Pearson product-momentcorrelation coefficient (r) which varies between –1.0 and +1.0. A value of the coefficient of +1.0 indicates perfect positive correlation (in the sense that increases in one variable accompany increases in the other) whilst a value of –1.0 indicates a perfect negative correlation (increases in one variable accompany decreases in the other; they are negatively related). A correlation coefficient of zero indicates no correlation. The degree of similarity does not allow one to infer that variations in one quantity actually cause variations in the other. Multiple correlation measures the extent to which more than one variable are related. Partial correlation measures the extent to which variables are related while holding constant the statistical effects of one or more variables. (Saich, 2014).
Kurian, G. T. (2011). Correlation. In The Encyclopedia of Political Science (pp. 341-341). Washington, DC: CQ Press doi: 10.4135/9781608712434.n330
Saich, P. (2014). Correlation analysis. In J. Matthews (Ed.), Encyclopedia of environmental change (pp. 226-226). Thousand Oaks,, CA: SAGE Publications, Ltd. doi: 10.4135/9781446247501.n863
Research Questions and Hypotheses
A hypothesis is defined as a proposition designed to be tested in the research project. To achieve testability, all variables in the hypothesis must be clearly stated and must be capable of empirical measurement. Research hypotheses may be univariate, bivariate, or multivariate ,,,,,,,,,,,,,,,,, formulate hypotheses using the available variables
(BAILEY, 2007).
quantitative concepts are ubiquitous
Population and Sample
a population is the entire collection of entities one seeks to understand or, more formally, about which one seeks to draw an inference. Consequently, defining clearly the population of interest is a fundamental component of research design because the way in which the population is defined dictates the scope of the inferences resulting from the research effort. (Huck, Beavers, & Esquivel, 2010).
simple random samples, each member of the population must have an equal probability of being included in the sample. It follows that each possible sample of size n has an equal probability of being selected from the population. After a list of the population’s members (i.e., the sampling frame) is created, a random number generator, a random numbers table, or some other unbiased method is used to generate the sample. (Huck, Beavers, & Esquivel, 2010).
Huck, S., Beavers, A. & Esquivel, S. (2010). Sample. In N. J. Salkind (Ed.), Encyclopedia of research design (pp. 1395-1299). Thousand Oaks, CA: SAGE Publications, Inc. doi: 10.4135/9781412961288.n395
Informed Consent and Confidentiality
Geographic Location and Data Collection
Instrumentation
Questionnaire construction, as a middle component of the research sequence, is subject to a number of constraints that are not always well recognized. First and foremost is the necessity for the questionnaire to faithfully measure the concepts in the hypotheses. But other constraints are also imposed after questionnaire construction, chiefly sampling constraints, data-collection constraints, and quantitative data-analysis constraints. The questionnaire constrains the sampling design. If the questionnaire is very short and easily administered, this facilitates the use of a complicated sample design. However, if the questionnaire is complex, then sample size may need to be reduced. The construction of a large and complex questionnaire means that it is difficult and time-consuming to conduct a large number of interviews.
the questionnaire must be designed to collect data that meet the statistical assumptions of the quantitative techniques to be used. Questionnaires can quickly become long and complicated. Furthermore, there is a tendency to construct closed-ended questions with not more than seven answer categories. While such nominal or ordinal data are often used in regression analyses, they are marginally inappropriate for ordinary least squares (OLS) regression and other quantitative techniques that assume interval or ratio data. (BAILEY, 2007).
Indicator variables …
Dependent variables Definition
Overall quality Overall quality determines the quality if the quality of crowns is acceptable, excellent, or unacceptable. (Appendix A)
Seating time Seating time is the time that dentists spend to fit the crown in the mouth (Appendix A)
Rx followed Rx is the written structure (paper commination) that explains the dentist’s expectations (prescription) (Appendix A)
Fit Adapting the prosthetic edge to the abutment which is
the (prepped tooth) (Appendix A)
Occlusion Relationship between upper and lower jaws (Appendix A)
Contacts Contacts surface between adjacent teeth (Appendix A)
Contour Overall shape of the crown (Appendix A)
Shade Color of the crown that matches the natural tooth (Appendix A)
Anatomy Detailed feature of natural tooth (Appendix A)
Emergence profile Blending the crown from the side with the rest of the crowns
Margin Edge of the prosthesis crown (Appendix A)
Due date Appointment date that patient comes back to dental office
(Appendix A)
Predictor variables …
Predictor variables Definition
Adherence to Prep-Guide A communication and training tool for the dentist to
prepare the tooth for the crown (Appendix A)
Effectiveness of Dentist-Technician Communication The level of proper understanding between technicians and dentists (Appendix A)
Field Test or Pilot Testing
Validity and Reliability
Measurement is the assignment of numbers to attributes or properties of people, objects, or events based on a set of rules (Stevens, 1968).( Aguinis, Henle, & Ostroff, 2001).
Reliability refers to the extent that a measure is dependable, stable, and consistent over time. If a measure is reliable, there is consistency between two sets of scores on a measure( Aguinis, Henle, & Ostroff, 2001).
The concept of reliability assumes that scores obtained from a measure include a ‘true’ score or accurate representation of an individual’s level of the attribute being measured. For example, if we give a typing test to job applicants, we assume that the test is assessing their true ability to type( Aguinis, Henle, & Ostroff, 2001).
In order to increase the reliability of a measure, errors of measurement must be minimized. Ideally, they should be completely eliminated. By decreasing error and subsequently increasing reliability, it is more likely the measure will reflect an individual’s true possession of the attribute measured. ( Aguinis, Henle, & Ostroff, 2001).
Methods for estimating the reliability of a measure use the correlation coefficient to assess the relationship or degree of consistency between two sets of scores. The reliability coefficient can range from 0 to 1, with numbers closer to one indicating high reliability and little measurement error, and values closer to zero indicating low reliability and a large amount of measurement error. ( Aguinis, Henle, & Ostroff, 2001).
The quality of a research design is typically assessed in terms of internal and external validity. Internal validity refers to how much confidence we have that variation in the dependent variable is really attributable to the independent variable and not some spurious, nuisance variable. External validity refers to the extent to which findings can be generalized to other people, situations, and times. (Levine, 2009).
Nominal Scales or any other
A nominal scale is the most basic and it involves assigning numbers as labels to individual objects (e.g., telephone numbers) or categories of objects (e.g., sex, organizational unit). Nominal scales determine whether objects belong in the same or different categories (e.g., male or female) based on a given attribute (e.g., sex). Thus, nominal scales classify people or objects. ( Aguinis, Henle, & Ostroff, 2001).
Ordinal scales involve assigning numbers to people or objects so that their rank order can be determined. That is, ordinal scales help decide if one person is equal to, greater than, or less than another based on a given attribute. For example, a supervisor believes María is a better performer than Bob, thus María is given a 2 while Bob is assigned a 1 to show María has a higher performance ranking than Bob. However, this does not indicate the magnitude of the difference between María’s and Bob’s performance levels, we just know that María is better than Bob. ( Aguinis, Henle, & Ostroff, 2001).
Interval Scales
Interval, like ordinal scales, assign numbers to reflect whether individuals or objects are greater than, less than, or equal to each other. However, interval scales also indicate the difference between objects on a particular attribute. ( Aguinis, Henle, & Ostroff, 2001).
Ratio Scales
Ratio scales have a true zero point. The true zero point is the point at which no amount of the attribute is present. Because a zero point can be determined, the ratio between actual scores of an attribute can be examined. ( Aguinis, Henle, & Ostroff, 2001).
Aguinis, H., Henle, C. & Ostroff, C. (2001). Measurement in work and organizational psychology. In N. AndersonD. S. Ones & H. K. Sinangil Handbook of industrial, work & organizational psychology – volume 1: Personnel psychology (Vol. 2, pp. 27-50). London: SAGE Publications Ltd doi: 10.4135/9781848608320.n3
Internal Validity
Internal validity is an evaluation of a special type of “internal relationship” that can occur between variables in a study. Specifically, internal validity evaluates whether a cause-and-effect relationship between variables can be determined (Barron, K., Brown, A., Egan, T., Gesualdi, C. & Marchuk, 2008).
A concern with whether the variation in the independent variable(s) caused or influenced observed variation in the dependent variable(s). Threats to internal validity (e.g., selection effects, history, mortality, etc.) should be identified before making any conclusions. Furthermore, a research study can only be internally valid if it measures what it is intended to measure. (Sullivan, 2009).
Barron, K., Brown, A., Egan, T., Gesualdi, C. & Marchuk, K. (2008). Validity. In S. F. Davis & W. Buskist 21st century psychology: A reference handbook (Vol. 2, pp. I-55-I-64). Thousand Oaks, CA: SAGE Publications, Inc. doi: 10.4135/9781412956321.n7
Sullivan, L. E. (2009). Internal validity. In The SAGE glossary of the social and behavioral sciences (pp. 265-266). Thousand Oaks, CA: SAGE Publications, Inc. doi: 10.4135/9781412972024.n1344
External Validity
new external validity terms have been coined to capture unique generalizability issues in particular field
Specifically, population validity entails the extent to which findings can be generalized beyond the participants of a study to the population at large (Barron, K., Brown, A., Egan, T., Gesualdi, C. & Marchuk, 2008).
The degree to which research findings can be generalized. External validity includes the extent to which research findings can be applied to the population of interest. External validity also includes the extent to which research findings can be extended to different people, places, settings, times, outcomes, and treatment variations. (Sullivan, 2009).
Data Analysis
Correlation is a statistical measure of the relationship, or association, between two or more variables. There are many different types of correlations, each of which measures particular statistical relationships among and between quantitative variables. (Shapiro, 2008).
The value of the correlation between any two variables is typically given by a correlation coefficient, which can take on any value between and including − 1.00 (indicating a perfect negative relationship) up to and including +1.00 (indicating a perfect positive relationship). (Shapiro, 2008).
Probability
Statistical significance testing may be used when working with a random sample from a population, or a sample that is believed to approximate a random, representative sample. Statistical significance testing calls for subjective judgment in establishing a predetermined probability (ranges between 0 and 1.0) of making an inferential error caused by the sampling error. When using statistical significance testing, it requires the use of two forms of probability (P): calculated and critical. Statistical significance is met when P(CALCULATED) is less than P(CRITICAL); when this is the case, the null hypothesis can be “rejected.” Only when the null hypothesis is rejected are the results called “statistically significant.” This simply implies that the sample results are relatively unlikely, given the assumption that the null hypothesis is exactly true. (Salkind, 2008).
P(Critical)
One of the probabilities, P(CRITICAL), is also referred to as “alpha.” P(CRITICAL) is the probability of making a Type I error when testing a null hypothesis. A Type I error occurs when rejecting a null hypothesis that is true. Another possible type of error that can occur is a Type II error, which occurs when the null hypothesis is not rejected and it is false. The P(CRITICAL) is usually set before collecting the data and tends to be a small number. The most frequent alpha levels used are .05 and .01; by using a small number, the probability of error is minimized. (Salkind, 2008).
Phi and Crame ´r’s V Coefficients
The phi and Crame´r’s V coefficients are used to evaluate the strength of relationship between two nominal-level variables when the chi-square statistic has been found to be significant. The phi is used when the two nominal-level variables are dichotomous; the Crame´r’s V coefficient is used with nominal-level variables with more than two levels.
Spearman Rank-Order Correlation
The Spearman rank-order correlation coefficient (also known as Spearman’s rho or rs)isoneofthe best-known and most frequently used nonparametric statistics. It is used to examine the relationship between two continuous variables (e.g., age and level of depression). Its parametric alternative is the Pearson product-moment correlation coefficient. (Pett, 2008).
Like the point biserial correlation, Spearman’s rho is a special case of the Pearson r but is based on the ranking of observations, not their actual values. This test statistic can range in value between −1.0 and +1.0 with higher absolute values indicating a stronger relationship. The squared values of Spearman’s rho offer a reasonable estimate of the strength of the relationship between the two continuous variables of interest. (Pett, 2008).
Pett, M. (2008). Nonparametric statistics. In S. Boslaugh (Ed.), Encyclopedia of epidemiology (Vol. 1, pp. 737-743). Thousand Oaks, CA: SAGE Publications, Inc. doi: 10.4135/9781412953948.n321
Salkind, N. J. (2008). Statistical significance. In Encyclopedia of educational psychology (Vol. 1, pp. 944-945). Thousand Oaks, CA: SAGE Publications, Inc. doi: 10.4135/9781412963848.n261
Shapiro, J. (2008). Correlation. In P. J. Lavrakas (Ed.), Encyclopedia of survey research methods (pp. 155-156). Thousand Oaks, CA: SAGE Publications, Inc. doi: 10.4135/9781412963947.n110
Decision Rule
Securing the Data
Summary
References
Aboras, M. M., Muchtar, A., Azhari, C. H., & Yahaya, N. (2014). Type of failure of zirconia-based ceramics in dental laboratory in Misurata, Libya. Applied mechanics and materials, 575, 22-25. doi: http://dx.doi.org.contentproxy.phoenix.edu/10.4028/www.scientific.net/AMM.575.22
Ahangari, A., Ardakan, K., Mahdavi, F. and Ardakani, M. (2015). The Effect of two Shading Techniques on Value of Zirconia-Based Crowns. 16(2), pp.129-133.
Ahmed, S. (2019). Integrating DMAIC approach of Lean Six Sigma and theory of constraints toward quality improvement in healthcare. Reviews on Environmental Health, 0(0).
Akifuddin, S. (2015). Reduction of Complications of Local Anaesthesia in Dental Healthcare Setups by Application of the Six Sigma Methodology: A Statistical Quality Improvement Technique. JOURNAL OF CLINICAL AND DIAGNOSTIC RESEARCH.
Akifuddin, S. (2015). Reduction of Complications of Local Anaesthesia in Dental Healthcare Setups by Application of the Six Sigma Methodology: A Statistical Quality Improvement Technique. JOURNAL OF CLINICAL AND DIAGNOSTIC RESEARCH.
Alammari, M. and Albagar, R. (2018). Assessment of the perceived communication competence of senior undergraduate dental students: A study of the quality of data and orders written in prosthodontics’ laboratory forms. Journal of International Oral Health, 10(1), pp.16-20.
Alkinaidri, A. and Alsulami, H. (2018). Improving Healthcare Referral System Using Lean Six Sigma. American Journal of Industrial and Business Management, 08(02), pp.193-206.
Alomari, M., & Chadwick, R. G. (2011). Factors influencing the shade matching performance of dentists and dental technicians when using two different shade guides. British dental journal, 211(11), 7. doi: http://dx.doi.org/10.1038/sj.bdj.2011.1006
Al-Qatawneh, L., Abdallah, A. and Zalloum, S. (2019). Six Sigma Application in Healthcare Logistics: A Framework and A Case Study. Journal of Healthcare Engineering, 2019, pp.1-12.
Alshiddi, I. F. (2014). Communication between dental office and dental laboratory: From Paper-based to web-based. Pakistan oral & dental journal, 34(3) Retrieved from https://search.proquest.com/docview/1695990809?accountid=35812
Antony, J., Palsuk, P., Gupta, S., Mishra, D. and Barach, P. (2018). Six Sigma in healthcare: a systematic review of the literature. International Journal of Quality & Reliability Management, 35(5), pp.1075-1092.
Anupama, P. (2014). Adoption of Six Sigma DMAIC to reduce cost of poor quality. International journal of productivity and performance management, Vol. 63 Issue: 1, pp.103-126, https://doi.org/10.1108/IJPPM-01-2013-0018
Apsari, A. (2017). The Importance of Abutment Teeth Preparation Guide for Telescopic Double Crown Restorations with Friction Element. DENTA, 11(1), 69.
Arbab Ali, S., Khalifa, N. and Nasser Alhajj, M. (2018). Communication Between Dentists and Dental Technicians During the Fabrication of Removable Partial Dentures in Khartoum State, Sudan. Acta Stomatologica Croatica, 52(3), pp.246-253.
Avgousti, K. (2013). Research Philosophy, methodology, quantitative, and qualitative methods. The Cyprus journal of sciences, 11, 33-43. Retrieved from https://search.proquest.com/docview/1516144410?accountid=35812
Ayse, B. C., & Schou, L. (2014). Interrelation between patient satisfaction and patient-provider communication in diabetes management. The scientific world journal, 2014 doi: http://dx.doi.org/10.1155/2014/372671
Bacoup, P., Michel, C., Habchi, G., & Pralus, M. (2018). From a quality management system (QMS) to a lean quality management system (LQMS). TQM Journal, 30(1), 20-42. Retrieved from https://search-proquest-com.contentproxy.phoenix.edu/docview/1977763704?accountid=35812
Bahadori, M., Raadabadi, M., Ravangard, R., & Baldacchino, D. (2015). Factors affecting dental service quality. International journal of health care quality assurance, 28(7), 678-689. doi: http://dx.doi.org/10.1108/IJHCQA-12-2014-0112
Bin-Shuwaish, M. (2017). Compliance of dental laboratory technicians with dentists’ instructions for fabrication of a PFM crown. The Saudi Journal for Dental Research, 8(1-2), pp.35-41.
Bin-Shuwaish, M. S. (2017). Compliance of dental laboratory technicians with dentists’ instructions for fabrication of a PFM crown. The Saudi journal for dental research, 8(1–2), 35–41. https://doi-org.contentproxy.phoenix.edu/10.1016/j.sjdr.2016.06.001
Brown, J. S., Collins, A., & Duguid, P. (1989). Situated cognition and the culture of learning. Educational Researcher, (1), 32. https://doi.org/10.2307/1176008
Burns, L. (2013). Why Dentists Are Changing Laboratories. Proofs, 96(4), 32–36. Retrieved from http://search.ebscohost.com/login.aspx?direct=true&AuthType=shib&db=bth&AN=87510537&site=eds-live&scope=site
Byrne, M., Tickle, M., Glenny, A., Campbell, S., Goodwin, T. and O’Malley, L. (2018). A systematic review of quality measures used in primary care dentistry. International Dental Journal, 69(4), pp.252-264.
Carey, R., Bhattacharyya, S., Kehl, S., Matukas, L., Pentella, M., Salfinger, M. and Schuetz, A. (2018). Implementing a quality management system in the medical microbiology laboratory. Clinical Microbiology Reviews, 31(3).
Cionca, N., Hashim, D. and Mombelli, A. (2016). Zirconia dental implants: where are we now, and where are we heading? Periodontology 2000, 73(1), pp.241-258.
Cohen, J. (1988). Statistical power analyses for the social sciences. Hillsdale, NJ: Lawrence Erlbauni Associates.
Coskun, A., Serteser, M. and Ünsal, I. (2018). Sigma metric revisited: True known mistakes. Biochemia medica, 29(1), pp.142-148.
Danese, P., Romano, P., & Bortolotti, T. (2012). JIT production, JIT supply and performance: Investigating the moderating effects. Industrial Management & Data Systems, 112(3), 441-465. doi:10.1108/02635571211210068
Dastjerdi, H., Khorasani, E., Yarmohammadian, M. and Ahmadzade, M. (2016). Evaluating the application of failure mode and effects analysis technique in hospital wards: a systematic review. Journal of Injury and Violence Research, 9(1), pp.51-60.
Dental Quality Alliance (2019). Quality measurement in dentistry: A Guidebook. Improving Oral Health through Measurement. [online] pp.1-68. Available at: https://www.ada.org/~/media/ADA/DQA/2019_Guidebook.pdf?la=en [Accessed 28 Nov. 2019].
Eakle, W. and Hatrick, C. (2015). Dental Materials: Clinical Applications for Dental Assistants and Dental Hygienists. 3rd ed. Elsevier.
East London NHS Foundation Trust (2019). Pareto Chart: Quality Improvement. [online] Qi.elft.nhs.uk. Available at: https://qi.elft.nhs.uk/resource/pareto-charts/ [Accessed 29 Nov. 2019].
El-Sayed, A. and Ahmed Mousa, M. (2015). The impact of cooperative learning in teaching communication skills for psychiatric nursing Students. The Eurasia Proceedings of Educational & Social Sciences (EPESS), 3, pp.74-77.
Etikan, I., Musa, S. A., & Alkassim, R. S. (2016). Comparison of convenience sampling and purposive sampling. American journal of theoretical and applied statistics, 5(1), 1-4.
Fagerlind Ståhl, A., Gustavsson, M., Karlsson, N., Johansson, G. and Ekberg, K. (2015). Lean production tools and decision latitude enable conditions for innovative learning in organizations: A multilevel analysis. Applied Ergonomics, 47, pp.285-291.
Fowler, S. B., & Lapp, V. (2019). Sample size in quantitative research: Sample size will affect the significance of your research. American nurse today, 14(5), 61–62. Retrieved from http://search.ebscohost.com/login.aspx?direct=true&AuthType=shib&db=ccm&AN=136584614&site=eds-live&scope=site
Furterer, S. and Hernandez, E. (2019). Improving the Healthcare Quality Measurement System Using Attribute Agreement Analysis Assessing the Presence and Stage of Pressure Ulcers. International Journal of Statistics and Probability, [online] 8(4), pp.47-59. Available at: https://pdfs.semanticscholar.org/2a4e/66add4941557c0ddbc3aae57d887d6bd123a.pdf [Accessed 29 Nov. 2019].
Gaylor, L. (2016). The Administrative Dental Assistant. Elsevier Health Sciences.
Gignac, G. E., & Szodorai, E. T. (2016). Effect size guidelines for individual differences researchers. Personality and individual differences, 102, 74-78.
Gupta, V., Jain, R., Meena, M. L., & Dangayach, G. S. (2018). Six-sigma application in tire-manufacturing company: A case study. Journal of industrial engineering international, 14(3), 511-520. doi: http://dx.doi.org.contentproxy.phoenix.edu/10.1007/s40092-017-0234-6
Hamasaki, T., Kato, H., Kumagai, T., & Hagihara, A. (2017). Association between dentist-dental hygienist communication and dental treatment outcomes. Health communication, 32(3), 288–297. https://doi.org/10.1080/10410236.2016.1138376
Hamasaki, T., Kato, H., Kumagai, T., & Hagihara, A. (2017). Association between dentist-dental hygienist communication and dental treatment outcomes. Health communication, 32(3), 288–297. https://doi.org/10.1080/10410236.2016.1138376
Hamed Khawka, Z. (2016). Detecting Total Quality Management Status and Teamwork Orientation in Al-Yarmouk Teaching Hospital. American Journal of Industrial and Business Management, 06(03), pp.232-248.
Harel, Z., Silver, S., McQuillan, R., Weizman, A., Thomas, A., Chertow, G., Nesrallah, G., Chan, C. and Bell, C. (2016). How to Diagnose Solutions to a Quality of Care Problem. Clinical Journal of the American Society of Nephrology, 11(5), pp.901-907.
Harr, R. (2001). TQM in dental practice. International journal of health care quality assurance, 14(2), 69-81. doi: http://dx.doi.org/10.1108/09526860110386528
Improta, G., Cesarelli, M., Montuori, P., Santillo, L. and Triassi, M. (2017). Reducing the risk of healthcare-associated infections through Lean Six Sigma: The case of the medicine areas at the Federico II University Hospital in Naples (Italy). Journal of Evaluation in Clinical Practice, 24(2), pp.338-346.
Institute for Healthcare Improvement (2019). Pareto Chart. [online] Ihi.org. Available at: http://www.ihi.org/resources/Pages/Tools/ParetoDiagram.aspx [Accessed 29 Nov. 2019].
Institute for Healthcare Improvement (n.d.). Failure Modes and Effects Analysis (FMEA) Tool: Copy (2) of Access to Prosthetic Dental Services. [online] Available at: https://app.ihi.org/Workspace/tools/fmea/ProcessDetailDataReport.aspx?ToolId=6597&ScenarioId=7774&Type=1 [Accessed 29 Nov. 2019].
Johnson, R. (2015). Improving productivity and quality of a transformer production line by applying lean manufacturing principles (Order No. 1590110). Available from ProQuest Dissertations & Theses Global. (1693995703). Retrieved from https://search-proquest-com.contentproxy.phoenix.edu/docview/1693995703?accountid=35812
Johnson, R. B., & Christensen, L. (2019). Educational research: Quantitative, qualitative, and mixed approaches. Thousand Oaks, CA: Sage.
Jung-Lang, C. (2008). Implementing six-sigma via TQM improvement: An empirical study in Taiwan. TQM Journal, 20(3), 182-195. doi: http://dx.doi.org.contentproxy.phoenix.edu/10.1108/17542730810867218
Khoshnevisan, M., Dehghanian, D., Heydarpoor, P. and Attaran, N. (2019). Clinical governance in general dental practice. Journal of International Oral Health, 11(3), p.107.
Kirkire, M., Rane, S. and Jadhav, J. (2015). Risk management in medical product development process using traditional FMEA and fuzzy linguistic approach: a case study. Journal of Industrial Engineering International, 11(4), pp.595-611.
Kontonasaki, E., Rigos, A., Ilia, C. and Istantsos, T. (2019). Monolithic Zirconia: An Update to Current Knowledge. Optical Properties, Wear, and Clinical Performance. Dentistry Journal, 7(3), p.90.
Kourtis, S., Bachlava, E. and Roussou, V. (2016). Esthetic rehabilitation with zirconia-based shell crowns: a case report. International Journal of Dentistry and Oral Health, 2(4), pp.102-106.
Lameira, D., Silva, W., Silva, F. and De Souza, G. (2015). Fracture Strength of Aged Monolithic and Bilayer Zirconia-Based Crowns. BioMed Research International, 2015, pp.1-7.
Li, M., Huang, Z., Dong, T., Tang, C., Lyu, B. and Yuan, J. (2018). Surface quality of Zirconia (ZrO2) Parts in shear-thickening high-efficiency polishing. Procedia CIRP, 77, pp.143-146.
Li, M., Zhang, Y., Lu, Y., Yu, W., Nong, X. and Zhang, L. (2017). Factors influencing two-way referral between hospitals and the community in China: A system dynamics simulation model. SIMULATION, 94(9), pp.765-782.
Li, X., He, M. and Wang, H. (2017). Application of failure mode and effect analysis in managing catheter-related blood stream infection in intensive care unit. Medicine, 96(51), p.e9339.
Li, Z. Y., Bai, H. F., Wang, Y., & Sun, Y. C. (2018). Research status of tooth preparation quantitative guide technique. Zhonghua kou qiang yi xue za zhi= Zhonghua kouqiang yixue zazhi= Chinese journal of stomatology, 53(2), 137-140.
Liu, H., You, X., Tsung, F. and Ji, P. (2018). An improved approach for failure mode and effect analysis involving large group of experts: An application to the healthcare field. Quality Engineering, 30(4), pp.762-775.
Lutfiyya, M., Chang, L., McGrath, C., Dana, C. and Lipsky, M. (2019). The state of the science of interprofessional collaborative practice: A scoping review of the patient health-related outcomes-based literature published between 2010 and 2018. PLOS ONE, 14(6), p.e0218578.
Mark, M. & Reichardt, C. (2008). Quasi-experimental and correlational designs: methods for the real world when random assignment isn’t feasible. In C. SansoneC. Morf & A. Panter The SAGE handbook of methods in social psychology (pp. 265-286). Thousand Oaks, CA: SAGE Publications, Inc. doi: 10.4135/9781412976190.n12
Martín‐Ares, M., Barona‐Dorado, C., Guisado‐Moya, B., Martínez‐Rodríguez, N., Cortés‐Bretón‐Brinkmann, J., & Martínez‐González, J. M. (2016). Prosthetic hygiene and functional efficacy in completely edentulous patients: satisfaction and quality of life during a 5‐year follow‐up. Clinical oral implants research, 27(12), 1500-1505.
Meirowitz, A., Bitterman, Y., Levy, S., Mijiritsky, E., & Dolev, E. (2019). An in vitro evaluation of marginal fit zirconia crowns fabricated by a CAD-CAM dental laboratory and a milling center. BMC Oral Health, 19 doi: http://dx.doi.org/10.1186/s12903-019-0810-9
Mgbere, O., Singh, M. and Arafat, R. (2015). Measurement system analysis (MSA) of empirically derived composite measure of preventive care counseling practices of HIV medical care providers. International Journal of Medical Science and Public Health, 4(12), p.1640.
Mistry, K., Jaggers, J., Lodge, A., Alton, M., Mericle, J., Frush, K. and Meliones, J. (2019). Using Six Sigma® Methodology to Improve Handoff Communication in High-Risk Patients. [online] pp.1-11. Available at: https://www.ncbi.nlm.nih.gov/books/NBK43658/pdf/Bookshelf_NBK43658.pdf [Accessed 26 Nov. 2019].
Moccelini, B. S., De Alencar, N. A., Bolan, M., Magno, M. B., Maia, L. C., & Cardoso, M. (2018). Pulp necrosis and crown discoloration: a systematic review and meta‐analysis. International journal of paediatric dentistry, 28(5), 432-442.
Occupational Employment and Wages. (May 2018). Retrieved August 13, 2019, from https://www.bls.gov/oes/current/oes291021.htm#st
Ohno, T. (1988), Toyota Production System: Beyond Large-Scale Production, Productivity Press, Portland, OR.
Øilo, M., Schriwer, C., Flinn, B. and Gjerdet, N. (2019). Monolithic zirconia crowns – wall thickness, surface treatment and load at fracture. Biomaterial Investigations in Dentistry, 6(1), pp.13-22.
Özyemişci Cebeci, N. (2018). Factors Associated with Insufficient Removable Partial Denture Design Instructions. Dental and Medical Problems, 55(2), pp.173-177.
Pankaj Kumar, J. Maiti, Angappa Gunasekaran, (2018) “Impact of quality management systems on firm performance”, International journal of quality & reliability management, Vol. 35 Issue: 5, pp.1034-1059, https://doi.org/10.1108/IJQRM-02-2017-0030
Parry, G., Evans, J. and Cameron, A. (2014). Communicating Prosthetic Prescriptions from Dental Students to the Dental Laboratory: Is the Message Getting Through? Journal of Dental Education, 78(2), pp.1636-1642.
Prep Guide. (2019). [Photograph]. Retrieved from http://glidewelldental.com/wp-content/uploads/2016/02/all-ceramic-prep-guide.pdf
Pruitt, D. (2009). Experimental research on social conflict. In J. BercovitchV. Kremenyuk & I. W. Zartman the SAGE handbook of conflict resolution (pp. 102-118). London: SAGE Publications Ltd doi: 10.4135/9780857024701.n7
Rahman, A., Shaju, S. U. C., & Sarkar, S. K. (2018). Application of six sigma using define measure analysis improve control (DMAIC) methodology in garment sector. Independent journal of management & production, 9(3), 810-826. doi: http://dx.doi.org.contentproxy.phoenix.edu/10.14807/ijmp.v9i3.732
Raju, S., & Sowdaminit, T. (2015). Six sigma approach for productivity enhancement. Productivity, 56(2), 197-203. Retrieved from https://search-proquest-com.contentproxy.phoenix.edu/docview/1779946832?accountid=35812
Ridwan, A., Ekawati, R., & Novitasari, A. (2018). Quality control of the steel wire rod product by integration lean six sigma and taguchi method. MATEC Web of Conferences, 218, 4013. doi:10.1051/matecconf/201821804013
Salem, S., Al-Dossari, D., Al-Zaagi, I. and Qureshi, N. (2017). Lean Six Sigma, Root Cause Analysis to Enhance Patient Safety in Healthcare Organizations: A Narrative Review, 2000-2016. Journal of Advances in Medical and Pharmaceutical Sciences, 12(1), pp.1-26.
Schakaki, O. and Watson, A. (2017). A Study on the Effectiveness of Total Quality Management in Dental Patient Satisfaction. EC Dental Science, [online] 14(3), pp.114-149. Available at: https://www.ecronicon.com/ecde/pdf/ECDE-14-00481.pdf [Accessed 26 Nov. 2019].
Schmidt, A., Sousa-Zomer, T. T., Andrietta, J. M., & Cauchick-Miguel, P. A. (2018). Deploying six sigma practices to general electric subsidiaries in a developing economy: An empirical analysis. International journal of quality & reliability management, 35(2), 446-462. doi:10.1108/IJQRM-09-2016-0155
Schneebeli, E., Brägger, U., Scherrer, S. S., Keller, A., Wittneben, J. G., & Hicklin, S. P. (2017). Quality evaluation of zirconium dioxide frameworks produced in five dental laboratories from different countries. Journal of Prosthodontics, 26(5), 399-409.
Schriwer, C., Skjold, A., Gjerdet, N. and Øilo, M. (2017). Monolithic zirconia dental crowns. Internal fit, margin quality, fracture mode and load at fracture. Dental Materials, 33(9), pp.1012-1020.
Serdar PİRTİNİ. (2003). Communication related dimensions of TQM from the point of marketing and customer satisfaction view. Sosyal ekonomik araştırmalar dergisi, (6), 180. Retrieved from http://search.ebscohost.com/login.aspx?direct=true&AuthType=shib&db=edsdoj&AN=edsdoj.7c3aa22e79240f5a015419280f0825e&site=eds-live&scope=site
Sharma, P., Malik, S. C., Gupta, A., & Jha, P. C. (2018). A DMAIC six sigma approach to quality improvement in the anodizing stage of the amplifier production process. International journal of quality & reliability management, 35(9), 1868-1880. doi:10.1108/IJQRM-08-2017-0155
Shi, J., Li, X., Ni, J. and Zhu, Z. (2015). Clinical Evaluation and Patient Satisfaction of Single Zirconia-Based and High-Noble Alloy Porcelain-Fused-to-Metal Crowns in the Esthetic Area: A Retrospective Cohort Study. Journal of Prosthodontics, 25(7), pp.526-530.
Sippli, K., Rieger, M. and Huettig, F. (2017). GPs’ and dentists’ experiences and expectations of interprofessional collaboration: findings from a qualitative study in Germany. BMC Health Services Research, 17(1).
Skjold, A., Schriwer, C. and Øilo, M. (2018). Effect of margin design on fracture load of zirconia crowns. European Journal of Oral Sciences, 127(1), pp.89-96.
Snowdent, M., Ellwood, F., McSherry, R., Halsall, J. and Hough, D. (2017). Clinical Governance: A Friend or Foe to Dental Care Practice in the UK?. International Journal of Perceptions in Public Health, [online] 1(2), pp.112-120. Available at: https://core.ac.uk/download/pdf/81670978.pdf [Accessed 26 Nov. 2019].
Sogunro, O. A. (2002). Selecting a quantitative or qualitative research methodology: An experience. Educational research quarterly, 26(1), 3. Retrieved from https://search.proquest.com/docview/216183188?accountid=35812
Sunder, V. and Kunnath, N. (2019). Six Sigma to reduce claims processing errors in a healthcare payer firm. Production Planning & Control, pp.1-16.
Tadlaoui, K., Chafi, A. and Ennadi, A. (2018). The lean six sigma in a public hospital. Istrazivanja i projektovanja za privredu, 16(1), pp.60-69.
Timofe, M. and Albu, S. (2016). Quality Management in Dental Care: Patients’ Perspectives on Communication. A Qualitative Study. Medicine and Pharmacy Reports, 89(2), pp.287-292.
Tortorella, G., Augusto, B., França, S. and Sawhney, R. (2019). Assessment methodology for Lean Practices in healthcare organizations: case study in a Brazilian public hospital. Production, 29(0).
Tulbah, H., Alhamdan, E., Alqahtani, A., Alshahrani, A., & Alshaye, M. (2017). Quality of communication between dentists and dental laboratory technicians for fixed prosthodontics in Riyadh, Saudi Arabia. The Saudi dental journal, 29(3), 111-116. doi: 10.1016/j.sdentj.2017.05.002
von Scheel, H., von Rosing, M., Hove, M., Fonseca, M. and Foldager, U. (2015). Phase 2: Process Concept Evolution. The Complete Business Process Handbook, pp.11-35.
Walker, K. K., PhD., Jackson, R. D., D.M.D., & Maxwell, Lisa, LDH, B.S., M.S.N. (2016). The importance of developing communication skills: Perceptions of dental hygiene students. Journal of Dental Hygiene (Online), 90(5), 306-312. Retrieved from https://search.proquest.com/docview/1869508951?accountid=35812
Wang, G., Wang, C., & Qin, M. (2017). Pulp prognosis following conservative pulp treatment in teeth with complicated crown fractures—A retrospective study. Dental Traumatology, 33(4), 255-260.
Waylen, A. (2017). The importance of communication in dentistry. Dental Update, 44(8), pp.774-780.
Wilkinson, H., Whittington, R., Perry, L., & Eames, C. (2017). Does formulation of service users’ difficulties improve empathy in forensic mental health services. Journal of Forensic Psychology Research and Practice, 1-22.
Xue, Z., Li, H., Guan, R. and Chen, S. (2016). Applying healthcare failure mode and effect analysis to patient pain management in the anesthesia recovery period. Chinese Nursing Research, 3(1), pp.34-36.
Zhang, Y. and Kelly, J. (2017). Dental Ceramics for Restoration and Metal Veneering. Dental Clinics of North America, 61(4), pp.797-819.
Appendix A
Closed-ended Questionnaire for the Dentists
1. How was the Quality of overall cases?
a. acceptable b. excellent c. unacceptable
2. How long was the seating time?
a. Ideal b. too long c. unacceptably long
3. Did technician follow the Rx (written structure)?
a. yes b. no
4. How was the fit?
a. good b. tight c. loose
5. How was the occlusion?
a. good b. high c. Low
6. How were the contacts?
a. Good b. light c. open
7. How was the contour?
a. good b. over, c. under
8. How was the hade?
a. good b. dark, c. light
9. How was the anatomy?
a. good b. poor
10. How was the emergence profile?
a. good b. bulky c. under-contoured
11. How was the margin?
a. good b. open c. short
12. Did laboratory meet the Due date?
a. yes b. no
Appendix B
Figure1: Prep Guide for Metal-Free Restorations
AUTHOR BIOGRAPHY
[start section text here]