Survey on the teaching and use in dental schools of resin-based materials for restoring posterior teeth

Teaching of posterior composites for the restoration of permanent teeth in undergraduate dental training programmes: Systematic review and meta-analysis

OBJECTIVES

To systematically assess aspects of teaching of posterior composite restorations (PCRs) in permanent teeth in dental schools.

STUDY SELECTION

Quantitative studies reporting on dental schools' teaching regarding the placement of PCRs in permanent teeth. Random-effects meta-analyses and meta-regressions were performed. Risk of bias was assessed based on the Medical Education Research Study Quality Instrument (MERSQI).

SOURCES

Electronic databases (MEDLINE via PubMed, EMBASE via Ovid, Web of Science, and Scopus) were searched in January 2023.

DATA

Forty sources reporting on 34 studies having surveyed 1,286 dental schools were included. Overall, 92.7% (95%-CI: 88.2-95.5) of dental schools reported to teach PCRs. PCRs in three-surface Class II cavities are taught by 82.0% (95%-CI: 70.4-89.7). The mandatory use of liners in deep cavities is taught by 78.3% (95%-CI: 68.9-85.5), and 44.0% (95%-CI: 34.3-54.2) reported to teach bulk-fill composites. While most posterior restorations placed by students were composites (56.1%; 95%-CI: 46.0-65.8), 94.7% (95%-CI: 86.6-98.0) of dental schools (still) teach posterior amalgam restorations. The proportion of dental schools teaching PCRs in three-surface Class II cavities increased and the mean proportion of PCRs among all posterior restorations increased over time (padj.≤0.003).

CONCLUSIONS

The teaching of PCRs in dental schools around the world reflects the increased use of resin composite in clinical practice, with students in countries where dental amalgam continues to be used, placing more posterior composites than restorations of dental amalgam. The teaching of PCRs, which is anticipated to increase, will continue to be refined with further developments in adhesive materials, devices, instrumentation, and techniques.

CLINICAL SIGNIFICANCE

Graduating dentists can be expected to be familiar with the use of resin composites for the restoration of posterior teeth.

Choice of Restorative Materials for Direct Posterior Restorations among Undergraduate Saudi College Students

Background:

The most common restorative materials used in dentistry are amalgam and composite. Amalgam is a controversial material owing to its mercury toxicity. With recent advances in the properties of composite materials, there has been a shift towards its use.

Objectives:

The aim of this study was to understand the perceptions of undergraduate dental students in a northern Saudi Arabian dental school about the choice of restorative materials for restoring posterior teeth.

Methodology:

The study included undergraduate students studying in 4th and 5th year dental program in College of Dentistry, Jouf University. A four-item questionnaire with 18 close-ended questions was developed by the investigators, which were hand delivered to all the students. Data analysis is presented through tables and descriptive methods.

Results:

A total of 98 (out of 131) undergraduate students participated in this study. Overall, the students reported a significantly strong influence of the type of restorative materials in relation to the cavity size and margin of the restorations along with the esthetics factor(p<0.05). There was slight influence on the student’s choice because of the instructor's influence, whereas the students felt they were knowledgeable and had appropriate training to use either amalgam or composite. The study also found that patient’s preference had a strong influence on choosing composite material. The students were mostly not influenced while choosing the material as far as the safety of it was concerned. However, the patient’s influence was slight when it came to the choice of the material. A significant difference was noted among the students when it came to pregnancy-related safety concerns where the choice of material was not influenced by either amalgam or composite (p=.002).

Conclusion:

The undergraduate dental students at College of Dentistry, Jouf University are comfortable in using both amalgam and composite as a posterior restorative material. They are knowledgeable about both the materials and are adequately trained to use either one.

What German dentists choose for their teeth: A Web-based survey of molar restorations and their longevity

STATEMENT OF PROBLEM

Which restorative material is best suited for treating the posterior molar region is unclear. As dentists presumably choose the most appropriate restoration, German dentists were asked how their own molars were treated.

PURPOSE

The purpose of this survey study was to examine molar restorations and their durability in German dentists.

MATERIAL AND METHODS

In the official journal of the Federal Dental Association, German dentists were asked to participate in an online survey that gathered demographic data and information on the type and durability of their molar restorations. To reduce selection bias, the data were weighted for region, sex, and age of the dentist.

RESULTS

The data set consisted of 1719 molars from 288 dentists. Restorations included gold inlays (25%), composite resin (24.3%), amalgam (11.8%), ceramic inlays (5.4%), glass ionomer cement or compomer (0.8%), gold crowns (21.8%), ceramic crowns (6.6%), and metal-ceramic crowns (4.3%). Notable differences were identified based on the sex, age, and region of the dentist. Women selected increased esthetic options, as did young dentists. Restorations made of gold, amalgam, and base metal had the highest longevity, at more than 20 years CONCLUSIONS: Among German dentists, restorations with metallic materials dominated in molars, with gold accounting for the largest share. In recent years, the proportion of tooth-colored restorations has increased, and in particular, young dentists use composite resin and ceramics.

Dental educators' attitudes towards the teaching of dental amalgam

OBJECTIVE

To ascertain dental educators' attitudes towards the teaching of dental amalgam at dental schools in Australia and identify preferred curricular approaches in a potentially "amalgamless" profession.

METHODS

A mixed methods analysis was employed based on an open-ended response survey followed by a closed-ended questionnaire. Identification of key issues from the survey helped frame the questionnaire. Participants included those with expertise in operative and restorative dentistry, with direct involvement in curriculum development or delivery, at Australian dental schools.

RESULTS

Participants numbered fifteen and represented seven of the nine dental schools in Australia. Key themes identified and explored included the following: (in)consistency of approach to teaching restorative dentistry; a perceived disconnect between undergraduate study and the "real world"; a need for a focus on teaching of alternatives to dental amalgam (80 per cent (strongly) agreeing); the contradictory nature of the evidence base and literature that is not readily understood; the need for more post-graduate education relating to adhesive restorative materials (86 per cent (strongly) agreeing); the need for dental amalgam to continue to be available; formal understandings (guidelines) as to the use of dental amalgam; dental schools in Australia being heard on these issues; and the relevance of this issue (100 per cent (strongly) agreeing the issue is topical and important).

CONCLUSION

There is a broad consensus of dental educators at Australian dental schools as how best to approach the teaching of amalgam if a phase-down is to occur and the issues any such approach may face.

The Dental Amalgam Phasedown in New Zealand: A 20-year Trend

BACKGROUND AND OBJECTIVES

Information on the choice of material and performance of restorations placed in a dental practice annually is limited. The Minamata Convention on Mercury is likely to affect the use of amalgam worldwide. The objective of this research was to investigate the use of restorative materials at the University of Otago Faculty of Dentistry in New Zealand from 1998 to 2017.

METHODS

Data from the Faculty of Dentistry's database from the years of interest were compiled. These data included information on the characteristics of restorations, including information on the material used and number of surfaces involved for each restoration. The tooth in which each restoration was placed was categorized by arch, tooth type, and deciduous or permanent dentition.

RESULTS

Records identified 227,514 permanent restorations placed from January 1998 to December 2017, of which 91.7% were direct restorations. Among direct restorations, composite resin was the most commonly used material, followed by amalgam, glass ionomer, and compomer. The use of amalgam for direct restorations decreased from 52.3% of direct restorations in 1998 to 7.1% in 2017. A corresponding increase was observed in the use of tooth-colored direct restorations, particularly composites. Among indirect restorations, porcelain fused to metal, gold, and stainless steel (in pediatric applications) were the materials most frequently used.

CONCLUSIONS

Despite having no official policy on reducing the use of dental amalgam, the Faculty of Dentistry is following the global trend in reducing its use, with composite resin now well established as the predominant restorative material used. If the current rate of decline persists unchecked, the Faculty of Dentistry could transition to being amalgam free by 2020, although it seems likely that the characteristics and principles of use of the material (and its removal) will be taught for some time to come. This knowledge is important to planning curriculum changes needed to prepare graduates for clinical practice.

Co-Blend Application Mode of Bulk Fill Composite Resin

Objective: To evaluate the effect of a new application method of bulk-fill flowable composite resin material on bond-strength, nanoleakage, and mechanical properties of dentine bonding agents. Materials and methods: Sound extracted human molars were randomly divided into: manufacturer’s instructions (MI), manual blend 2 mm (MB2), and manual blend 4 mm (MB4). Occlusal enamel was removed and flattened, dentin surfaces were bonded by Prime & Bond universal (Dentsply and Optibond FL, Kerr). For the MI group, adhesives were applied following the manufacturer’s instructions then light-cured. For MB groups, SDR flow+ bulk-fill flowable composite resin was applied in 2- or 4-mm increment then manually rubbed by a micro brush for 15 s with uncured dentine bonding agents and the mixture was light-cured. Composite buildup was fabricated incrementally using Ceram.X One, Dentsply nanohybrid composite resin restorative material. After 24-h water storage, the teeth were sectioned to obtain beams of about 0.8 mm² for 24-h and thermocycled micro-tensile bond strength at 0.5 mm/min crosshead speed. Degree of conversion was evaluated with micro-Raman spectroscopy. Contraction gaps at 24 h after polymerization were evaluated and atomic force microscopy (AFM) nano-indentation processes were undertaken for measuring the hardness across the interface. Depth of resin penetration was studied using a scanning electron microscope (SEM). Bond strength data was expressed using two-way ANOVA followed by Tukey’s test. Nanoindentation hardness was separately analyzed using one-way ANOVA. Results: Factors “storage F = 6.3” and “application F = 30.11” significantly affected the bond strength to dentine. For Optibond FL, no significant difference in nanoleakage was found in MI/MB4 groups between baseline and aged specimens; significant difference in nanoleakage score was observed in MB2 groups. Confocal microscopy analysis showed MB2 Optibond FL and Prime & Bond universal specimens diffusing within the dentine. Contraction gap was significantly reduced in MB2 specimens in both adhesive systems. Degree of conversion (DC) of the MB2 specimens were numerically more compared to MS1 in both adhesive systems. Conclusion: Present study suggests that the new co-blend technique might have a positive effect on bond strengths of etch-and-rinse adhesives to dentine.

Dental cavity liners for Class I and Class II resin-based composite restorations

BACKGROUND

Resin-based composite (RBC) is currently accepted as a viable material for the restoration of caries for posterior permanent teeth requiring surgical treatment. Despite the fact that the thermal conductivity of the RBC restorative material closely approximates that of natural tooth structure, postoperative hypersensitivity is sometimes still an issue. Dental cavity liners have historically been used to protect the pulp from the toxic effects of some dental restorative materials and to prevent the pain of thermal conductivity by placing an insulating layer between restorative material and the remaining tooth structure. This is an update of the Cochrane Review first published in 2016.

OBJECTIVES

The objective of this review was to assess the effects of using dental cavity liners in the placement of Class I and Class II resin-based composite posterior restorations in permanent teeth in children and adults.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 12 November 2018), the Cochrane Central Register of Controlled Trials (CENTRAL; 2018, Issue 10) in the Cochrane Library (searched 12 November 2018), MEDLINE Ovid (1946 to 12 November 2018), Embase Ovid (1980 to 12 November 2018) and LILACS BIREME Virtual Health Library (Latin American and Caribbean Health Science Information database; 1982 to 12 November 2018). We searched ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases.

SELECTION CRITERIA

We included randomized controlled trials assessing the effects of the use of liners under Class I and Class II posterior resin-based composite restorations in permanent teeth (in both adults and children). We included both parallel and split-mouth designs.

DATA COLLECTION AND ANALYSIS

We utilized standard methodological procedures prescribed by Cochrane for data collection and analysis. Two review authors screened the search results and assessed the eligibility of studies for inclusion against the review inclusion criteria. We conducted risk of bias assessments and data extraction independently and in duplicate. Where information was unclear we contacted study authors for clarification.

MAIN RESULTS

Eight studies, recruiting over 700 participants, compared the use of dental cavity liners to no liners for Class I and Class II resin-based composite restorations.Seven studies evaluated postoperative hypersensitivity measured by various methods. All studies were at unclear or high risk of bias. There was inconsistent evidence regarding postoperative hypersensitivity (either measured using cold response or patient-reported), with a benefit shown at some, but not all, time points (low-quality evidence).Four trials measured restoration longevity. Two of the studies were judged to be at high risk and two at unclear risk of bias. No difference in restoration failure rates were shown at 1 year follow-up, with no failures reported in either group for three of the four studies; the fourth study had a risk ratio (RR) 1.00 (95% confidence interval (CI) 0.07 to 15.00) (low-quality evidence). Three studies evaluated restoration longevity at 2 years follow-up and, again, no failures were shown in either group.No adverse events were reported in any of the included studies.

AUTHORS' CONCLUSIONS

There is inconsistent, low-quality evidence regarding the difference in postoperative hypersensitivity subsequent to placing a dental cavity liner under Class I and Class II posterior resin-based composite restorations in permanent posterior teeth in adults or children 15 years or older. Furthermore, no evidence was found to demonstrate a difference in the longevity of restorations placed with or without dental cavity liners.

Reparative Dentistry: Possibilities and Limitations

Purpose of Review

Defective dental restorations are amongst the most common encounters in general dental practice. Replacement of defective restorations is often costly and commonly results in the sacrifice of sound tooth structure, thereby compromising the vitality of the dental pulp, potentially resulting in the acceleration of the restoration cycle and premature loss of the restored tooth. With advances in adhesive dentistry, ‘reparative dentistry’ is becoming an important area of minimally invasive dentistry. This article highlights the detrimental biological effects of restoration replacement and provides an overview of current knowledge and understanding of restoration repair as a safe and effective alternative approach to replacement.

Recent Findings

The literature reviewed showed that a growing body of evidence from clinical studies indicates that repaired restorations have similar survival outcomes in patients with low and medium caries risk compared to replaced restorations and are clinically acceptable over a 12-year follow-up of clinical service. Teeth with repaired restorations are less likely to require aggressive interventions such as endodontic treatment or extraction compared to those with replaced restorations.

Summary

Repair options should be carried out wherever possible as minimally interventional procedures in order to increase the longevity of the remaining part of the restoration and the restored tooth unit. Restoration replacement should be considered as the last resort when there are no other viable alternatives.

Dental cavity liners for Class I and Class II resin-based composite restorations

BACKGROUND

Resin-based composite (RBC) is currently accepted as a viable material for the restoration of caries for posterior permanent teeth requiring surgical treatment. Despite the fact that the thermal conductivity of the RBC restorative material closely approximates that of natural tooth structure, postoperative hypersensitivity is sometimes still an issue. Dental cavity liners have historically been used to protect the pulp from the toxic effects of some dental restorative materials and to prevent the pain of thermal conductivity by placing an insulating layer between restorative material and the remaining tooth structure.

OBJECTIVES

The objective of this review was to assess the effects of using dental cavity liners in the placement of Class I and Class II resin-based composite posterior restorations in permanent teeth in children and adults.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 25 May 2016), the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 4) in the Cochrane Library (searched 25 May 2016), MEDLINE Ovid (1946 to 25 May 2016), Embase Ovid (1980 to 25 May 2016) and LILACS BIREME Virtual Health Library (Latin American and Caribbean Health Science Information database; 1982 to 25 May 2016). We searched ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases.

SELECTION CRITERIA

We included randomized controlled trials assessing the effects of the use of liners under Class I and Class II posterior resin-based composite restorations in permanent teeth (in both adults and children). We included both parallel and split-mouth designs.

DATA COLLECTION AND ANALYSIS

We utilized standard methodological procedures prescribed by Cochrane for data collection and analysis. Two review authors screened the search results and assessed the eligibility of studies for inclusion against the review inclusion criteria. We conducted risk of bias assessments and data extraction independently and in duplicate. Where information was unclear we contacted study authors for clarification.

MAIN RESULTS

Eight studies, recruiting over 700 participants, compared the use of dental cavity liners to no liners for Class I and Class II resin-based composite restorations.Seven studies evaluated postoperative hypersensitivity measured by various methods. All studies were at unclear or high risk of bias. There was inconsistent evidence regarding postoperative hypersensitivity (either measured using cold response or patient-reported), with a benefit shown at some, but not all, time points (low-quality evidence).Four trials measured restoration longevity. Two of the studies were judged to be at high risk and two at unclear risk of bias. No difference in restoration failure rates were shown at one year follow-up, with no failures reported in either group for three of the four studies; the fourth study had a risk ratio (RR) 1.00 (95% confidence interval (CI) 0.07 to 15.00) (low-quality evidence). Three studies evaluated restoration longevity at two years follow-up and, again, no failures were shown in either group.No adverse events were reported in any of the included studies.

AUTHORS' CONCLUSIONS

There is inconsistent, low-quality evidence regarding the difference in postoperative hypersensitivity subsequent to placing a dental cavity liner under Class I and Class II posterior resin-based composite restorations in permanent posterior teeth in adults or children 15 years or older. Furthermore, no evidence was found to demonstrate a difference in the longevity of restorations placed with or without dental cavity liners.

Does the adhesive strategy influence the post-operative sensitivity in adult patients with posterior resin composite restorations?: A systematic review and meta-analysis

OBJECTIVES

A systematic review and meta-analysis were performed on the risk and intensity of postoperative sensitivity (POS) in posterior resin composite restorations bonded with self-etch (SE) and etch-and-rinse (ER) adhesives.

SOURCE

A comprehensive search was performed in the MEDLINE via PubMeb, Scopus, Web of Science, LILACS, BBO and Cochrane Library and SIGLE without restrictions. The abstracts of the annual conference of the IADR (1990-2014), unpublished and ongoing trials registry were also searched. Dissertations and theses were searched using the ProQuest Dissertations and Periodicos Capes Theses databases.

STUDY SELECTION

We included randomized clinical trials that compared the clinical effectiveness of SE and ER used for direct resin composite restorations in permanent dentition of adult patients. The risk/intensity of POS was the primary outcome. The risk of bias tool of the Cochrane Collaboration was used. The meta-analysis was performed on the studies considered 'low' risk of bias.

DATA

After duplicates removal, 2600 articles were identified but only 29 remained in the qualitative synthesis. Five were considered to be 'high' risk of bias and eleven were considered to be 'unclear' in the key domains, yielding 13 studies for meta-analysis. The overall relative risk of the spontaneous POS was 0.63 (95% CI 0.35 to 1.15), while the stimuli-induced POS was 0.99 (95% CI 0.63 to 1.56). The overall standardized mean difference was 0.08 (95%CI -0.19 to 0.35). No overall effect was revealed in the meta-analyses, meaning that no influence of the ER or SE strategy on POS.

SIGNIFICANCE

The type of adhesive strategy (ER or SE) for posterior resin composite restorations does not influence the risk and intensity of POS. CRD42014006617.

Dentists' restorative decision-making and implications for an 'amalgamless' profession. Part 1: a review

The Minamata Convention has agreed to a worldwide reduction and ultimate elimination in the production and use of mercury containing products. This will have implications for the practice of dentistry. Australian organizations' pronouncements on the issue are limited and research examining the Australian context dated. The restoration of teeth with direct materials has changed significantly since the 1980s. Up to this time amalgam was the material of choice for direct posterior restorations. Its properties and guidelines for placement were, and remain, well established. Resin composite has replaced amalgam as the material of choice in many clinical situations. Despite inherent clinical disadvantages compared to amalgam, there continues to be a shift toward greater use of resin composite. There is consensus worldwide that the restoration of posterior teeth using resin composite now exceeds that of amalgam. The reasons for this are reviewed in this article along with current evidence and commentary relating to direct restorative and evidence-based decision-making, minimally invasive approaches, and approaches to education. The implications for these in an 'amalgamless' profession are identified.