|Year : 2021 | Volume
| Issue : 2 | Page : 156-163
Dentists’ restorative treatment decisions: A south african study
Razia Z Adam
Restorative Dentistry, Faculty of Dentistry, University of the Western Cape, Tygerberg, Cape Town, South Africa
|Date of Submission||17-Sep-2020|
|Date of Decision||02-Dec-2020|
|Date of Acceptance||23-Dec-2020|
|Date of Web Publication||17-Apr-2021|
Dr. Razia Z Adam
Restorative Dentistry, Faculty of Dentistry, University of the Western Cape, Private Bag X1, Tygerberg, 7505 Cape Town.
Source of Support: None, Conflict of Interest: None
Aim: To focus on clinical decision-making by dentists for defective restorations in the context of an overburdened healthcare system and a high caries rate. Materials and Methods: A cross-sectional study was conducted using mixed-methods. An online survey was administered to all members of the South African Dental Association followed by in-depth interviews of 15 purposefully selected dentists in the Western Cape. The online data included demographic data, education level, knowledge, attitudes, and practises related to dental amalgam use. The interviews consisted of two patient cases where dentist were asked to explain their treatment decisions. Quantitative data was analysed using statistical software SAS (SAS Institute Inc., Cary, NC, USA) and a Chi-square test and Spearman’s correlation was used with P < 0.05. The interviews were coded, transcribed, and analysed using the Atlas.ti ® software. Responses were analysed using the framework method. Results: A significant relationship was found between dentists with more than 21 years of experience and the repair of defective restorations (P = 0.0027*). Remaining tooth structure and the presence of pain were the most important clinical factors influencing treatment decisions. Non-clinical factors such as fear, ethical conscience, cost to patient and dental school had an influence on their decisions. Conclusion: Clinical factors and non-clinical factors influence dentists’ treatment decisions. There was a lack of translation of evidence-based information to everyday general practice dentistry in South Africa. These results have implications in changing current continuing professional education activities and motivating policy makers to incentivize preventive and minimally invasive dentistry.
Keywords: Dental amalgam, dental restoration failure, dentistry, operative, repair
|How to cite this article:|
Adam RZ. Dentists’ restorative treatment decisions: A south african study. J Int Oral Health 2021;13:156-63
| Introduction|| |
Decision-making is an important component of the clinical activities of a dentist, whether deciding to extract a tooth or to replace a defective restoration. Dental restorations are often described as “permanent” but in reality, do not last a lifetime. There is documented evidence that each time a restoration is replaced, the size of the cavity increases and the tooth structure is further compromised with an increased possibility of pulpal involvement.
It is widely accepted that dental caries is an “initially reversible, chronic, disease process with a known multi-factorial aetiology.” However, in recent years, there has been a trend in caries management to move away from the operative model towards a more preventive approach—minimum intervention dentistry., This includes strategies that curb the disease process and conserve tooth structure. Approximately 72% of amalgam restorative treatment is performed to replace existing restorations and dentists are frequently faced with a clinical decision either to replace or repair a defective amalgam restoration. Costly, advanced dental procedures such as root canal treatment and indirect restorations, or extractions may be avoided if the dentist has the knowledge and skills to recommend and perform repairs of defective restorations.
Current management options for the management of defective amalgam restorations include repair, refurbishing, and sealing of the restoration.,,, The clinical decision-making process for determining the treatment approach in the management of defective dental restorations is naturally complex. The decision to intervene is influenced by patient factors, tooth factors, material factors, and dentist factors. Studies conducted around the world confirm that there is much variation in clinicians’ decisions to intervene and although the repair and refurbish approach has been included in teaching curricula, there is a slow translation to the dental practice.,,
In order to understand the clinical decision-making process regarding the management of defective dental amalgam restorations, the present study used Bader and Shugars’ conceptual model on caries-related treatment decisions. Three types of patient factors are included in this conceptual model on caries-related treatment decisions: (i) those involving a specific tooth or tooth surface; (ii) those describing intra-oral conditions; and (iii) those related to patient history, behavior preferences, and socioeconomic status. In addition, dentist factors such as biases, including dentists’ beliefs of treatment preferences, utilities, and preferred diagnostic methods are also included in the model.
There has been a limited number of studies focusing on clinical decision-making and the management of defective amalgam restorations.,,,, Little research has reported on the factors influencing clinical decision-making, specifically in the context of South Africa where “generations of heavy metal patients have multiple restorations that are likely to need replacement or maintenance throughout their lifetime.”, In addition, most of the research is conducted in countries with well-run health care systems and where caries risk levels are low. This gap in the knowledge provides a unique opportunity to understand the influence dentists have on treatment choices.
The null hypothesis of the study was that South African dentists’ practises do not vary with respect to the management of defective dental amalgam restorations by personal and dental practice characteristics. The purpose of this study was to determine which factors affect South African dentists’ decisions to retreat defective dental amalgam restorations and to understand the influence of dentists’ knowledge age and practice profile.
| Materials and Methods|| |
Setting and design
A mixed methods approach with an explanatory sequential design with parallel sampling was used in this study over a period of 6 months. In the first phase, all participants provided informed written consent. An online survey was administered to all 3076 general practice members of the South African Dental Association in 2015. Dentists employed in the public sector and at an academic institution were excluded. After that, in-depth interviews of purposefully selected sample of dentists in the Western Cape were conducted. These 15 dentists were selected based on age, gender, and fee structure of the practice.
The questionnaire was adapted from the literature and included demographic data and knowledge on the management of defective dental amalgam restorations.,, The questionnaire was piloted to ensure validity and reliability.
The in-depth interviews comprised two patient vignettes in which dentists were asked to explain their treatment decisions with regards to the management of defective dental amalgam restorations. The think aloud technique was used to provide insight into their decision-making behavior. No new generation of knowledge was used as data saturation. The interviews were audio recorded and then transcribed and coded using the Atlas More Details.ti® software package. Responses were analyzed using the Framework Method. Peer review was used to ensure validity.
The Survey Monkey® program collected responses and automatically converted data into an Excel spreadsheet. Data analyses was performed using the statistical software SAS (SAS Institute Inc., Cary, NC, USA). Different statistical tests were performed to examine the relationships between the various factors in the categories: dentists’ individual characteristics, practice profiles, and biases.
A Chi-square test was used when both variables were categorical. When both variables were ordinal, the Spearman’s correlation was used. Cross-tabulations were only completed for the pairs that were significant at the 0.05 and 0.005 levels.
| Results|| |
A final sample of 324 general dental practitioners participated in the online survey with a response rate of 10.7%. The majority of the respondents were male and had more than 21 years of experience in dental practice [Table 1]. Data saturation with the in-depth interviews reached after 15 dentists. The majority of these respondents had more than 10 years of experience as dentists. In this research, repair was defined as the removal of only the defective part of the restoration and/or adjacent tooth tissue followed by placement of a new partial restoration. Replacement defined as the removal of the entire restoration followed by the placement of a new restoration. Refurbishment defined as the refinishing and polishing of a restoration to improve the surface and appearance.
Tooth factors such as remaining tooth structure, the size and depth of the restoration, and the presence of caries [Table 2] ranked as the most important factors when deciding on how to retreat a defective dental amalgam restoration. There was a statistically significant difference in the factors taken into consideration when replacing a defective dental amalgam restoration depending on the selection, X²(2) = 282.71, P < 0.0001*. Pairwise comparisons, “cost to the patient” and “future plans for the tooth” were chosen significantly less often than pain, visible caries, and remaining tooth structure (P < 0.0001*) [Table 3]. Similarly, the “cost to the patient” was chosen significantly more often than all the other options when deciding to repair or refurbish a defective dental amalgam restoration (P = 0.0048*) [Table 4]. Material factors ranked as the least important consideration.
One participant confirmed that funding influenced treatments, while two others remained cognizant about the financial well-being of their patients and “work according to their budget” (Dr LE).
You know, treatments are influenced by funding (Dr K).
I normally work according to their budget (Dr LE).
One participant expressed concern that if they were not competitive in the pricing of their treatment, the patients would consult another colleague.
In our practice, because we are working with people who want economical dentistry, what tends to happens if I tell a patient that I am going to charge her R650, they rather go somewhere and have it done for whatever the cheapest price is (Dr A).
Dentist factors: dentists’ knowledge
Eight percent of the participants agreed that there is no correlation between marginal gap and secondary caries. Sixty percent agreed that the size of the marginal gap present is directly related to the risk of secondary caries [Table 4]. The majority of the participants were in favor of repairing defective dental amalgam restorations as a treatment.
Interestingly, some participants felt that repairing a defective dental amalgam restoration was not the “right” thing to do as a health professional. The appropriateness of the treatment was questioned.
I don’t think that it [repairing a defective dental amalgam restoration] is the best you can do (Dr LE).
Participants also questioned the science behind using two different materials.
Well, I find that if I do that then the filling mostly, it could fail. I don’t want anybody really to come back with problems and tell me, ‘But you could have told me, or you could have done something more expensive for me, and why didn’t you do that in the first place?’ (Dr LE).
There was a statistically significant relationship and a trend that dentists who were contracted to third-party funders were more likely to repair defective dental amalgam restorations than to replace them (P = 0.0024*). No significant relationship was found between age and the decision to repair or not [Table 5].
|Table 5: Relationship between dentists characteristics and the decision to repair or not|
Click here to view
Patient factors: patient preference of dental material
Approximately one-half of the respondents (57%) indicated that the choice of dental material is discussed with the patient, while only 11% (n = 33) seldom did.
Participants of the interviews were acutely aware of the concern some patients expressed regarding the safety of dental amalgam as a restorative material:
[A] lot of our patients that come in ... you know patients are becoming very knowledgeable now, and they have Internet now and smart phones so when they walk through the door, they can tell you exactly what they want or what they need, and you are like okay. In the past as well, there was a whole fear of amalgams and mercury (Dr J).
| Discussion|| |
A worldwide trend towards minimally invasive dentistry and a dearth of information on the restorative treatment practices and clinical decision-making of South African dentists, specifically on how defective dental amalgam restorations are managed by dentists in private practice, motivated the present study. This study was conducted to explore South African (SA) dentists’ restorative treatment decisions. The present study identified clinical and non-clinical factors that acted as predictors for decision-making by SA dentists to repair or replace defective dental amalgam restorations. The literature reports on several factors that are responsible for the variations in clinical decision-making by dentists and these include dental training, knowledge of the disease, dentists’ preferences, and specific factors relating to the tooth or restorative material.,,,,,
Using the Bader and Shugars conceptual model as a framework, this research suggests that the current models regarding clinical decision-making in restorative dentistry can be implemented in countries affected by resource-strapped health systems and high caries settings. In addition, the interviews conducted in this project found that non-clinical factors such as fear, ethical conscience, and dental school training also exerted an influence on the decision process as depicted in [Figure 1].
Tooth factors such as remaining tooth structure, size, and depth of the restoration and the presence of caries were ranked higher than patient factors (viz. occlusion, finances, and presence of pain) and material factors. This finding was supported by previously published research in which technical factors dominated patient-related factors., The literature has identified an emphasis in teaching of the technical aspects without creating an awareness of the importance of patient outcome as a possible reason for this.
In this research, visible caries was the most important consideration when replacing a restoration. In contrast to Gordan et al., there was only a 25% probability that dentists would repair a restoration with a diagnosis of secondary caries. This could mean that dentists were not confident that a repair would yield a positive treatment outcome in the presence of caries and that caries could recur. Similarly, participating dentists were less likely to repair in the presence of a marginal gap.
In South Africa, only 14% of the population are members of a medical/health insurance scheme. Health insurance only provides limited cover for dental health-related services. This means that individuals visiting dental health facilities, private or public, may have to pay for the service. In this study, dentists only recommended repairing a defective dental amalgam restoration if patients were unable to afford an indirect restoration or a complete replacement of the restoration. Data from the interviews illustrated how dentists considered the cost and benefits to themselves as operators (i.e. How long it will take?), to the patient (i.e. Will the patient “benefit” from the treatment?), and to the profession (i.e. Will the patient perceive dentistry as beneficial?). Recent studies on repairing restorations have reported positive patient outcomes, and the technique may also be capable of improving the patient’s perception of dentistry.
Dentists participating in this project ranked “cost to patient” as the most important consideration in their decision to repair or refurbish a defective dental amalgam restoration. These findings corroborated those reported by Brennan and Spencer. Dentists who were interviewed were cognizant of the financial difficulties that patients experienced and “worked according to their [patient’s] budget” (Dr LE). The dentists provided different levels of restorative care based on their perception of the patient’s ability to pay. This demonstrated their willingness to provide the best level of care within the financial constraints set by the patient. However, if patients did not experience any symptoms, dentists were reluctant to suggest treatment, especially if there was concern about the patient’s ability to pay and treatment was delayed until absolutely necessary when the patient reported a symptom such as pain. Insight from the interviews also suggested that dentists felt uneasy with recommending a treatment such as a repair when they were unsure about the clinical effectiveness.
Gordan et al. found that dentists who did not determine the caries risk of patients were more likely to choose a more invasive intervention than a preventative treatment. Interestingly in this study, the caries risk of a patient was only considered important when refurbishing a restoration. The lack of use of preventive dentistry concepts in treatment decisions of dentists in the present study may be related to the dentists’ knowledge, patient demand, dental training, or the health system. In addition, given that the majority of dentists in this study had more than 15 years of experience, they may not be familiar or comfortable with the incorporation of preventive strategies in their practices, strategies that may be more time-consuming but not necessarily more financially rewarding. In South Africa, health systems do not reward dentists for adopting a more preventive approach in caries management. It is also possible that South African dental schools may not specifically and actively incorporate preventive methods in the comprehensive management of adult patients. This could be researched further.
A significant relationship was found between the age of the dentist and the repair of dental amalgam restorations. In contrast to previous studies, older dentists were more inclined to repair than replace defective dental amalgam restorations as they may have more clinical experience.,,
Gender did not have any influence on treatment decisions although previous studies noted a difference in treatment approaches., Riley et al. found that female dentists were more conservative and more inclined to use caries-preventive measures. The small number of female dentists participating in this study could account for not detecting a difference in treatment approaches.
The only factor found to have a significant relationship with repair of defective dental amalgam restorations was “contracted to third party funders.” Surprisingly, dentists who were contracted to medical aids were more likely to repair defective dental amalgam restorations. Data from the interviews and the online survey reported concern among participating dentists in placing an additional financial burden on patients when a defective dental restoration required treatment. The repair of a defective restoration could be classified as a restoration, and no additional authorization or payment would be necessary from the medical aid. However, if the patient presented with pain, dentists were reluctant to repair restorations. In this instance, a root canal or crown would be more appropriate, which could incur additional costs that may need to be paid by the patient.
Similar to the qualitative investigation into factors affecting treatment decisions by Kay and Blinkhorn, participating dentists in the present study expressed concern over the ethics, cost, and benefits of the repair procedure. Some dentists felt that repairing a restoration was “not the best treatment a dentist could offer” (Dr LE). Other participants regarded the repair of defective restorations as “patchwork” and “not the right thing to do” (Dr LE). This supports the findings of Sharif et al. and could largely be attributed to a lack of knowledge of alternative therapies to replacement and outdated beliefs regarding the relationship between marginal gaps and secondary caries and research has shown that dentists are more likely to replace a restoration that they did not originally place.,,,
It is also possible that dentists are drawing from their experience as dental students and how they managed similar cases. Most dental schools in South Africa use the quota system in teaching restorative dentistry, and students are sometimes asked to replace restorations to gain more experience with a technique or a restorative material. While this may improve technical ability, the dental student has also learnt not to trust the work of colleagues by indiscriminately replacing restorations. Attitudes, preferences, and beliefs are co-curricular activities that students learn consciously and unconsciously. This behavior shapes the behavior of the future dentist and affects practice patterns.
Another factor that may influence dentists’ clinical decision making is fear. The literature has described dentists’ fears to include fear of litigation, fear of consequences of clinical decisions, fear of cost to patients, and fear of cost to practice/dentists. Dentists who were interviewed expressed fear of facing patients as a consequence of an unsuccessful clinical decision and the possibility of incurring additional costs for the patient when a treatment was unsuccessful. This may conflict with their decision to prioritize the patient’s well-being or to benefit financially from their professional recommendation, which may result in overtreatment. All of these relate to trust between a dentist and a patient and the belief that the dentist will always act in the patient’s best interest. The concern is that dentists would only recommend repairing a defective dental amalgam restoration if patients were not able to afford an indirect restoration or a complete replacement of the restoration. This is an example of Maryniuk’s explanatory model of practice pattern variation in which the dentist’s practice patterns are driven by a desire always to act in their patient’s best interest. Another fear dentists expressed was losing clientele to colleagues if they were not competitive enough with their costs for treatment. The dentist has to reach a compromise between providing the best appropriate treatment and cost effectiveness for the patient and for the practice.
| Conclusion|| |
In conclusion, the findings suggest that South African dentists face similar challenges to dentists in more well-developed countries where the caries levels are lower. A limitation to this study is the low response rate and the small sample group who participated in the interviews. This study also confirms that South African dentists’ treatment patterns and clinical decision-making processes are shaped by the teaching in dental schools. Their experiences as dental students create the initial caries scripts that will later mature into their individual practice beliefs and identity as a clinician. This implies that dental students should be exposed to a greater variety of cases to develop more scripts that they may draw on during the clinical decision-making process. In addition, the influence of non-clinical factors on clinical decision-making should remind clinical teachers and creators of curricula that both the social aspect of patient management and the focus on patient outcomes are equally important as developing technical competences in the discipline. Comprehensive management of patient cases should be investigated in preference over the quota system that is used in South African dental schools.
Ethical policy and institutional review board statement
Ethics approval was received from the Senate Research Committee (Project registration: 11/1/46). Research was ethically conducted according to the Helsinki Declaration.
Patient declaration of consent: (If in-vivo Study/Case reports)
Prof. R. Madsen from the University of Missouri is acknowledged for the statistical analyses.
Financial support and sponsorship
This study was completed as part of a doctoral degree and the sabbatical was funded by the office of the DVC Academic: Prof. Lawack.
Conflicts of interest
There are no conflicts of interest.
Data availability statement
The author may be contacted directly on corresponding mail.
| References|| |
Schwendicke F Tailored dentistry: From “one size fits all” to precision dental medicine? Oper Dent 2018;43:451-9.
Estay J, Martín J, Viera V, Valdivieso J, Bersezio C, Vildosola P, et al
. 12 years of repair of amalgam and composite resins: A clinical study. Oper Dent 2018;43:12-21.
Pitts NB Are we ready to move from operative to non-operative/preventive treatment of dental caries in clinical practice? Caries Res 2016;38:294-304.
Petersen PE. Future Use of Materials for Dental Restoration. Geneva: World Health Organisation; 2009.
Petersen PE The world oral health report 2003: Continuous improvement of oral health in the 21st
century—the approach of the WHO global oral health programme. Commun Dent Oral Epidemiol 2003;31:3-23.
Gordan VV, Riley JL III, Blaser PK, Mondragon E, Garvan CW, Mjör IA Alternative treatments to replacement of defective amalgam restorations: Results of a seven-year clinical study. J Am Dent Assoc 2011;142:842-9.
Gordan VV, Riley JL III, Rindal DB, Qvist V, Fellows JL, Dilbone DA, et al
; National Dental Practice-Based Research Network Collaborative Group. Repair or replacement of restorations: A prospective cohort study by dentists in the national dental practice-based research network. J Am Dent Assoc 2015;146:895-903.
Moncada G, Vildósola P, Fernández E, Estay J, de Oliveira Júnior OB, de Andrade MF, et al
. Longitudinal results of a 10-year clinical trial of repair of amalgam restorations. Oper Dent 2015;40:34-43.
Moncada G, Fernández E, Mena K, Martin J, Vildósola P, De Oliveira Junior OB, et al
. Seal, replacement or monitoring amalgam restorations with occlusal marginal defects? Results of a 10-year clinical trial. J Dent 2015;43:1371-8.
Kanzow P, Wiegand A, Wilson NHF, Lynch CD, Blum IR Contemporary teaching of restoration repair at dental schools in Germany—close to universality and consistency. J Dent 2018;75:121-4.
Kanzow P, Wiegand A, Göstemeyer G, Schwendicke F Understanding the management and teaching of dental restoration repair: Systematic review and meta-analysis of surveys. J Dent 2018;75:121-4.
Hatipoğlu O, Arıcıoğlu B Repair versus replacement: A questionnaire examining the repair preferences of Turkish dentists in dental restorations. Int J Oral Dent Health2019;5:077.
Bader JD, Shugars DA What do we know about how dentists make caries-related treatment decisions? Commun Dent Oral Epidemiol 1997;25:97-103.
Gordan VV, Garvan CW, Richman JS, Fellows JL, Rindal DB, Qvist V, et al
; DPBRN Collaborative Group. How dentists diagnose and treat defective restorations: Evidence from the dental practice-based research network. Oper Dent 2009;34:664-73.
Gordan VV, Riley JL III, Geraldeli S, Rindal DB, Qvist V, Fellows JL, et al
; Dental Practice-Based Research Network Collaborative Group. Repair or replacement of defective restorations by dentists in the dental practice-based research network. J Am Dent Assoc 2012;143:593-601.
de Carvalho Martins BM, Nogueira Leal da Silva EJ, Masterson Tavares Pereira Ferreira D, Rodrigues Reis K, da Silva Fidalgo TK Longevity of defective direct restorations treated by minimally invasive techniques or complete replacement in permanent teeth: A systematic review. J Dent 2018;78:22-30.
Zafar MS, Ullah R, Qamar Z, Fareed MA, Amin F, Khurshid Z, et al
. Properties of dental biomaterials. In: Khurshid Z, Najeeb S, Zafar MS, Sefat F, editors. Advanced Dental Biomaterials. Cambridge: Woodhead Publishing; 2019. pp. 7-35.
Rekow ED, Bayne SC, Carvalho RM, Steele JG What constitutes an ideal dental restorative material? Adv Dent Res 2013;25:18-23.
Moncada G, Fernández E, Martín J, Arancibia C, Mjör IA, Gordan VV Increasing the longevity of restorations by minimal intervention: A two-year clinical trial. Oper Dent 2008;33:258-64.
Palotie U, Vehkalahti MM Reasons for replacement of restorations: Dentists’ perceptions. Acta Odontol Scand 2012;70:485-90.
Payne J Thinking aloud: Insights into information processing. Psychol Sci 1994;5:245-8.
Bader JD, Shugars DA Understanding dentists’ restorative treatment decisions. J Public Health Dent 1992;52:102-10.
Riley JL III, Gordan VV, Rouisse KM, McClelland J, Gilbert GH; Dental Practice-Based Research Network Collaborative Group. Differences in male and female dentists’ practice patterns regarding diagnosis and treatment of dental caries: Findings from the dental practice-based research network. J Am Dent Assoc 2011;142:429-40.
Signori C, Laske M, Mendes FM, Huysmans MDNJM, Cenci MS, Opdam NJM Decision-making of general practitioners on interventions at restorations based on bitewing radiographs. J Dent 2018;76:109-16.
Laske M, Opdam NJM, Bronkhorst EM, Braspenning JCC, Huysmans MCDNJM Risk factors for dental restoration survival: A practice-based study. J Dent Res 2019;98:414-22.
Patel N, Patel S, Cotti E, Bardini G, Mannocci F Unconscious racial bias may affect dentists’ clinical decisions on tooth restorability: A randomized clinical trial. JDR Clin Trans Res 2019;4: 19-28.
Eltahlah D, Lynch CD, Chadwick BL, Blum IR, Wilson NHF An update on the reasons for placement and replacement of direct restorations. J Dent 2018;72:1-7.
Signori C, Laske M, Bronkhorst EM, Huysmans MDNJM, Cenci MS, Opdam NJM Impact of individual-risk factors on caries treatment performed by general dental practitioners. J Dent 2019;81:85-90.
Gordan VV, Riley JL III, Worley DC, Gilbert GH; DPBRN Collaborative Group. Restorative material and other tooth-specific variables associated with the decision to repair or replace defective restorations: Findings from the dental PBRN. J Dent 2012;40:397-405.
Gray A, Vawda Y Health policy and legislation.S Afr Health Rev2017:13-24.
Blum IR, Özcan M, Blum IR Reparative dentistry: Possibilities and limitations. Curr Oral Heal Reports 2018;5:264-9.
Brennan DS, Spencer AJ Longitudinal comparison of factors influencing choice of dental treatment by private general practitioners. Aust Dent J 2006;51:117-23.
Maryniuk GA Practice variation: Learned and socio-economic factors. Adv Dent Res 1990;4:19-24.
Brennan DS, Spencer AJ The role of dentist, practice and patient factors in the provision of dental services. Commun Dent Oral Epidemiol 2005;33:181-95.
Kay EJ, Blinkhorn AS A qualitative investigation of factors governing dentists’ treatment philosophies. Br Dent J 1996;180: 171-6.
Sharif MO, Fedorowicz Z, Tickle M, Brunton PA Repair or replacement of restorations: Do we accept built in obsolescence or do we improve the evidence? Br Dent J2010;209:171-4.
Sharif MO, Merry A, Catleugh M, Tickle M, Brunton P, Dunne SM, et al
. Replacement versus repair of defective restorations in adults: Amalgam. Cochrane database Syst Rev 2014:CD005970.
Burke FJT, Lucarotti PSK The ultimate guide to restoration longevity in England and Wales. Part 10: Key findings from a ten million restoration dataset. Br Dent J 2018;225:1011-8.
Boyd MA Amalgam replacement: Are decisions based on fact or tradition? In: Anasuvice K, editor. Quality Evaluation of Dental Restorations: Criteria for Placement and Replacement. Chicago: Quintessence Publishing Company Inc; 1989. pp. 73-80.
Brennan DS, Spencer AJ Practice belief scales among private general dental practitioners. Aust Dent J 2001;46:186-93.
Fox C Evidence summary: Does dentists’ fear have an adverse effect on clinical decision-making? Br Dent J 2010;209:181-2.
Drake CW, Maryniuk GA, Bentley C Reasons for restoration replacement: Differences in practice patterns. Quintessence Int 1990;21:125-30.
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]