Teaching of composite restoration repair in Brazilian dental schools

OBJECTIVES

The aim was to investigate aspects of the teaching of restoration repair as a minimally invasive alternative to replacing defective direct composite restorations in undergraduate curricula teaching programs in Brazilian dental schools.

METHODS

A 14-item validated survey questionnaire was mailed to directors/coordinators of operative/restorative dentistry teachers of Brazilian Dental Schools. Data were collected on demographic characteristics of the teachers and institutions, together with questions on the teaching of the repair of defective resin-based composite restorations as part of the school curriculum; the rationale behind the teaching; the nature of the teaching (preclinical and/or clinical); how techniques were taught, indications for repair, operative techniques, materials used, patient acceptability and expected longevity of completed repairs.

RESULTS

Two hundred and twenty-two (94%) directors/ coordinators of dental curricula in Brazil were contacted. One hundred and thirty-one directors/coordinators (59%) replied, providing the e-mail address from the teacher responsible for the operative/restorative dentistry program in their school. Of these, 104 responded to the questionnaire (79% response rate). Ninety-three (89%) of the participating schools reported teaching composite repairs as an alternative to replacing restorations. Of the theoretical content, 43% was taught at preclinical and clinical levels, whereas most practical experience (53%) was acquired at clinical levels. Eighty-eight schools (95%) reported tooth substance preservation being the main reason for teaching repair techniques. All schools that taught repairs reported high patient acceptability.

CONCLUSIONS

The teaching of composite restoration repair as an alternative to restoration replacement is established in undergraduate programs in most of the Brazilian dental schools surveyed.

CLINICAL SIGNIFICANCE

The reasons for teaching restoration repair in Brazil were found to be quite unanimous among teachers, especially regarding the preservation of tooth structure. Variations were found in the clinical indications for repair, suggesting the need for further investigations. Monitoring repaired restorations should be encouraged and could contribute to future studies.

Teaching of the repair of defective composite restorations in Middle Eastern and North African Dental Schools

OBJECTIVES

To evaluate the status of teaching of repair of defective resin-based composite restorations in dental schools in the Middle Eastern and North African (MENA) countries.

METHODS

A validated 14-item questionnaire was mailed to the directors of the operative/restorative dentistry department in 40 MENA dental schools. Data were collected on teaching, including whether the repair of resin-based composite restorations was part of the dental school curriculum; the rationale behind the teaching; how techniques were taught, indications for repair, operative techniques, materials used, patient acceptability and expected longevity of the repair procedure.

RESULTS

Thirty-two schools responded to the survey (response rate of 80%). Twenty-two (69%) schools reported the teaching of resin-based composite repairs as an alternative to the replacement of restorations. Of the schools not teaching repairs, 80% indicated that they plan to include this topic in the curriculum within the next five years. Most schools taught theoretical and practical aspects of repair at a clinical level only. Two-thirds of schools reported tooth substance preservation being the main reason for teaching repair techniques. The main indications for repair treatment were marginal defects (59%), followed by partial loss of restoration (56%). Most schools that performed repairs reported high patient acceptability. Considerable variation was noted in relation to expected longevity of resin- based composite repairs.

CONCLUSIONS

The repair of defective resin-based composite restorations is actively taught within most of the surveyed schools. Advantages of repair, compared to replacement include minimum intervention, preservation of tooth structure, and savings of time and cost.

CLINICAL SIGNIFICANCE

The decision between replacing or repairing a defective resin-based composite restoration in the MENA region tends to be based on clinicians' subjective experience and judgement. However, to further enhance the teaching of resin-based composite repair standardised guidelines need to be developed based on existing evidence.

Fluorescence-aided selective removal of resin-based composite restorative materials: An in vitro comparative study

AIM

During removal of resin-based composite (RBC) restorations, removal of adjacent sound tooth structure can easily occur. The aim of the study was to compare the fluorescence-aided identification of restorations (FAIR) method with the conventional method (CM) using white light illumination for the selective removal of tooth-colored RBC restorations.

MATERIALS AND METHODS

Sixty extracted teeth were used to prepare 15 sets of models, each with four teeth. Cavities were prepared in each tooth and a digital three-dimensional scan of each model was taken in STL format. The teeth were then restored with either Admira Fusion, GRADIA DIRECT X, or TPH Spectra LV (20 teeth for each). Five dentists removed the restorations from sets of 12 teeth (six each using FAIR, and six using CM). From a postoperative scan, changes in intercuspal cavity width were measured using the 3D tool CAD software.

RESULTS

Using FAIR, changes in cavity width were not significant (P = .17), and there was no significant interoperator variance (P = .3). In contrast, when using CM, there was a significant increase in cavity width (P = .0025), and considerable interoperator variance (P = .03). FAIR allowed faster completion of the task of restoration removal (average time 100.23 seconds, vs 165.13 seconds from CM).

CONCLUSION

The FAIR method facilitates the selective removal of tooth-colored RBC restorations, with reduced time and less inadvertent removal of sound tooth structure.

CLINICAL SIGNIFICANCE

By enhancing the differentiation between the restorative material and adjacent tooth structure, the FAIR method facilitates removal of tooth-colored restorations, while concurrently prevents unnecessary removal of healthy tooth structure. The same approach may have applications for removal of resin-based materials such as resin cements under restorations, resin fissure sealants, and orthodontic brackets bonding resins.

A randomised controlled study on the effects of different surface treatments and adhesive self-etch functional monomers on the immediate repair bond strength and integrity of the repaired resin composite interface

OBJECTIVES

To evaluate the effects of different surface conditioning methods on the immediate repair bond strength and integrity of the repaired composite interface.

METHODS

One hundred and five resin composite blocks made of a nanohybrid resin composite were randomly assigned to one of the following surface conditioning groups (n = 15/group): Group 1: Gluma Self Etch™ adhesive system, Group 2: Tokuyama Bond Force II™ adhesive system, Group 3: non-roughened and non-conditioned surfaces, Group 4: sandblasting and Gluma Self Etch™, Group 5: sandblasting and Tokuyama Bond Force II™, Group 6: sandblasting only. A positive control group was also used. Resin composite identical to the substrate was applied and the repaired specimens were subjected to shear bond strength (SBS) testing. Representative samples from all groups were subjected to scanning electron microscopy and surface profilometry to determine their mode of failure. The data were analysed statistically using Analysis of Variance (ANOVA) and two independent sample t-test (α = 0.05).

RESULTS

The mean SBS of all test groups ranged between 1.92 and 5.40 MPa and varied with the degree of composite surface roughness and the type of adhesive system employed. Significantly highest SBS values (5.40 ± 0.36 MPa) were obtained in Group 5 (p = 0.017) which were comparable to the coherent strength of the resin composite in the positive control group (p > 0.05).

CONCLUSIONS

Under the tested conditions, significantly greater SBS of repaired resin composite was achieved when the substrate surface was conditioned by sandblasting followed by the application of the Tokuyama Bond Force II™ adhesive system.

CLINICAL SIGNIFICANCE

Effecting a repair of a nanohybrid composite restoration with sandblasting and the application of TBF II would seem to enhance the interfacial bond strength and integrity of the repaired resin composite interface. Clinical trials are necessary to determine the usefulness of this technique.

Restoration Repair as a Contemporary Approach to Tooth Preservation: Criteria for Decision Making and Clinical Recommendations

Despite the growing body of evidence-based knowledge, evidence-based restoration repair is not always applied in the clinical setting. This article is intended to give an evidence-based insight into the indications, importance, benefits and long-term success of resin composite restoration repair, together with details of relevant operative techniques aimed at conserving as much sound tooth structure as possible.

Repair increases the survival of failed primary teeth restorations in high-caries risk children: a university-based retrospective study

OBJECTIVES

We investigated factors associated with failure of adhesive restorations in primary teeth and whether repair may increase the survival of failed restorations placed in high-caries risk children.

MATERIALS AND METHODS

The sample comprised children who attended a university dental service to perform restorative treatment in primary teeth. Data were collected retrospectively from clinical records to assess the longevity of restorations. The outcomes were calculated in two levels: "Success" (Level 1)-when any re-intervention was considered as failure; "Survival" (Level 2)-when repaired restorations were considered clinically acceptable. The Kaplan-Meier survival test was used to analyze the longevity of restorations. Multivariate Cox regression with shared frailty was used to assess factors associated with failures (p < 0.05).

RESULTS

A total of 584 primary teeth restorations (178 patients) were included in the analysis. The longevity of restorations up to 36 months (Level 1) was 34.8% (AFR 29.6%). Multi-surface restorations showed significantly more failures than single-surface ones (HR 1.69; 95% CI 1.18, 2.41), and endodontically treated teeth presented more failures compared to vital teeth (HR 2.22; 95% CI 1.35, 3.65). There was an increase in restoration survival when repair was not considered as failure (p < 0.001). The survival of repaired restorations (Level 2) reached 43.7% (AFR 24.1%).

CONCLUSIONS

Adhesive restorations placed in primary teeth of high-caries risk children showed restricted longevity; however, the repair of failed restorations has increased its survival over time.

CLINICAL RELEVANCE

Repair is a more conservative and technically simple procedure that increases the survival of failed restorations in primary teeth.

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.

Shrinkage vectors of a flowable composite in artificial cavity models with different boundary conditions: Ceramic and Teflon

Polymerization shrinkage of dental resin composites leads to stress build-up at the tooth-restoration interface that predisposes the restoration to debonding. In contrast to the heterogeneity of enamel and dentin, this study investigated the effect of boundary conditions in artificial cavity models such as ceramic and Teflon. Ceramic serves as a homogenous substrate that provides optimal bonding conditions, which we presented in the form of etched and silanized ceramic in addition to an etched, silanized and bonded ceramic cavity. In contrast, the Teflon cavity presented a non-adhesive boundary condition that provided an exaggerated condition of poor bonding as in the case of contamination during the application procedure or a poor bonding substrate such as sclerotic or deep dentin. The greatest 3D shrinkage vectors and movement in the axial direction were observed in the ceramic cavity with the bonding agent followed by the silanized ceramic cavity, and smallest shrinkage vectors and axial movements were observed in the Teflon cavity. The shrinkage vectors in the ceramic cavities exhibited downward movement toward the cavity bottom with great downward shrinkage of the free surface. The shrinkage vectors in the Teflon cavity pointed towards the center of the restoration with lateral movement greater at one side denoting the site of first detachment from the cavity walls. These results proved that the boundary conditions, in terms of bonding substrates, significantly influenced the shrinkage direction.

Understanding the management and teaching of dental restoration repair: Systematic review and meta-analysis of surveys

OBJECTIVES

Repair instead of complete replacement is recommended to manage partially defective restorations. It is unclear if and why such treatment is taught at dental schools or practiced by dentists. We aimed to identify barriers and facilitators for repairs using a systematic review and meta- and qualitative analysis.

SOURCES

Electronic databases (PubMed, CENTRAL, Embase, PsycINFO) were searched.

STUDY SELECTION

Quantitative studies reporting on the proportion of (1) dentists stating to perform repairs, (2) dental schools teaching repairs, (3) failed restorations having been repaired were included. We also included qualitative studies on barriers/facilitators for repairs. Random-effects meta-analyses, meta-regression and a thematic analysis using the theoretical domains framework were conducted.

DATA

401 articles were assessed and 29, mainly quantitative, studies included. 7228 dentists and 276 dental schools had been surveyed, and treatment data of 30,172 restorations evaluated. The mean (95% CI) proportion of dentists stating to perform repairs was 71.5% (49.7-86.4%). 83.3% (73.6-90.0%) of dental schools taught repairs. 31.3% (26.3-36.7%) of failed restorations had been repaired. More recent studies reported significantly more dentists to repair restorations (p=0.004). Employment in public health practices and being the dentist who placed the original restoration were facilitators for repairs. Amalgam restorations were repaired less often, and financial aspects and regulations came as barriers.

CONCLUSIONS

While most dentists state to perform repairs and the vast majority of dental schools teach repairs, the proportion of truly repaired restorations was low. A number of interventions to implement repair in dental practice can be deduced from our findings.

CLINICAL SIGNIFICANCE

Partially defective restorations are common in dental practice. While repairs are taught and dentists are aware of the recommendation towards repairs, the actually performed proportion of repairs seems low.

Attitudes of Greek dentists towards repair of conservative restorations. An online survey

OBJECTIVES

Repair versus replacement of a defective direct restoration is one important step for conserving tooth structure. This study was designed to collect information on the attitudes of Greek dentists towards repairing direct restorations.

METHODS

An electronic questionnaire with 16 multiple-choice and rank-ordering questions was created online and its URL address was randomly emailed to 800 dentists in the area of Athens, Greece. The questionnaire remained open for 3 months, and after two reminder emails the data collected were analysed statistically to identify differences between clinician's sex or years of practicing dentistry, using the chi-square and Kruskal-Wallis tests at α = 0.05.

RESULTS

Three-hundred and twenty dentists completed and submitted the questionnaire (response rate = 40%). A high proportion (86.8%) of the respondents reported that they routinely repair defective restorations, ranking the order of their frequency as 2.47 for amalgam and 2.41 for resin restorations. The reasons, with the highest ranks, for repairing amalgams were the restoration of bulk fractures (4.10) and restoration of marginal fractures (3.69). For repair of resin restorations, the reasons with the highest ranks were improving their colour (4.04) and removing marginal discoloration (3.99). Moreover, 94.1% of the respondents stated that they were enough, much and very much satisfied with the repair, 1 year after it was performed.

CONCLUSIONS

A high percentage of Greek dentists are repairing defective direct restorations. There are discrepancies in the indications, techniques and materials used for repairs, such as bulk fractures and marginal restorations. Further studies on the efficacy of repairs, the criteria and procedure protocols are needed. Further, additional clinical education should be offered at the undergraduate or continuing education levels.

A Conservative Technique for Repairing Class IV Composite Restorations

Composite resin may make a restoration noticeable as time passes, on account of its color instability. The repair technique is a minimally invasive treatment for class IV composite resin restorations that show unsatisfactory coloration. Thus, the objective of the present article was to report a clinical case involving a conservative technique used for repairing a class IV composite resin restoration in the left maxillary central incisor and the replacement of a class IV restoration in the right maxillary central incisor.

Criteria for the Replacement of Restorations: Academy of Operative Dentistry European Section

The replacement of a restoration is one of the most common procedures in dentistry. However, the criteria for such intervention, excluding catastrophic failure and persistent discomfort and pain, continue to be the subject of considerable debate. The decision-making process remains subjective on the part of the treating clinician, while the evidence base for refurbishment and repair rather than replacement for the management of defective and failing restorations continues to grow and strengthen. This article, prepared as an Academy of Operative Dentistry European Section consensus publication, reviews existing criteria for the replacement of restorations and encourages practitioners to shift, if not already doing so, to considering the replacement of a restoration as a last resort rather than as a prudent action to be taken if in any doubt about clinical acceptability. Further research in the area, spanning the risk assessment of defective and failing restorations and new diagnostic tools and processes, together with work to enhance the evidence base of restoration repair vs replacement, would be of immense value.

Managing the phase-down of amalgam: Part I. Educational and training issues

Following the recently agreed Minamata Convention, a phase-down in the use of dental amalgam will become a priority for the profession. With a lead-in period of a number of years, important changes in the mind-set of the profession are required to ensure that patient safety is not compromised. Posterior composites have been a viable, and in many cases preferable, alternative to amalgam for many years. However, notwithstanding considerable developments in dental school teaching on the application and placement of posterior composites, growing evidence to support the use of composites in the restoration of posterior teeth and advances in composite systems, many practitioners remain reluctant to place composite rather than amalgam. This paper considers the present and future use of posterior composites and highlights ways in which dental school teaching and continuing professional development (CPD) may contribute to the successful phase-down, and now inevitable discontinuation, in the use of dental amalgam.

Managing the phase-down of amalgam: part II. Implications for practising arrangements and lessons from Norway

The announcement of the Minamata Convention has triggered the lead into a phase-down in the use of dental amalgam. This paper considers aspects of this development in the context of the experience of banning the use of dental amalgam in Norway. It is suggested that strong top-down leadership and joined-up working by all relevant stakeholders, including patients, may be one of the most important keys to an effective, seamless transition to the provision of preventatively orientated, patient-centred, minimally interventive operative dentistry, based on state-of-the-art selection and application of tooth-coloured restorative materials. The benefits of such a transition are considered to be an important goal for dentistry in the UK.

Failure Strengths of Composite Additions and Repairs

Purpose

When adding composite to a cured composite restoration, the intent is to achieve the same failure strength as the original restorative material. This study evaluated the failure strengths of added or repaired composite using various chemical and/or mechanical surface treatments.

Methods

Failure strengths were determined using a four-point bending test. Beam-shaped specimens were fabricated by adding new composite to cured composite (Filtek Supreme Ultra). The cured composites were either fresh or aged seven days (N=10-14). The composite surfaces were left unground or were ground before treatment with various combinations of roughening, acid etching, silane, and dental adhesives (conventional Adper SingleBond Plus or new multimode Scotchbond Universal) and/or tribochemistry (CoJet system). Monolithic composite specimens were the control. Failure strengths were statistically analyzed using one-way analysis of variance and the Fisher protected least significant difference (α=0.05).

Results

Failure strengths (mean ± standard deviation) when composite was added to unground freshly cured composites (111±25 MPa) and aged composites using a new multimode adhesive with (102±22 MPa) or without (98±22 MPa) tribochemical treatment were not significantly lower than the monolithic specimens (122±23 MPa). Grinding the surfaces of freshly cured composite significantly reduced failure strength, either with (81±30 MPa) or without (86±31 MPa) use of conventional adhesive. Failure strengths of aged composites were also significantly lower (51±21 MPa with SingleBond Plus), even after tribochemical treatment (71±29 MPa with SingleBond Plus; 73±35 MPa with Silane-Visiobond).

Conclusions

Using a new multimode adhesive when adding composite to freshly cured or aged composite substrates recovered the failure strength to that of the original monolithic composite.

Can repair increase the longevity of composite resins? Results of a 10-year clinical trial

OBJECTIVES

The aim of this double-blind clinical trial was to assess the longevity of repairs to localized clinical defects in composite resin restorations that were initially planned to be treated with a restoration replacement.

METHODS

Twenty-eight patients aged 18-80 years old with 50 composite resin restorations (CR) were recruited. The restorations with localized, marginal, anatomical deficiencies and/or secondary caries adjacent to CR that were "clinically judged" to be suitable for repair or replacement according to the USPHS criteria were randomly assigned to Repair (n=25) or Replacement (n=25) groups, and the quality of the restorations was scored according to the modified USPHS criteria. The restorations were blind and two examiners scored them at baseline (Cohen Kappa agreement score 0.74) and at ten years (Cohen Kappa agreement score 0.87) restorations. Wilcoxon tests were performed for comparisons within the same group (95% CI), and Friedman tests were utilized for multiple comparisons between the different years within each group.

RESULTS

Over the decade, the two groups behaved similarly on the parameters of marginal adaptation (MA) (p>0.05), secondary caries (SC) (p>0.05), anatomy (A) (p<0.05), and colour (C) (p>0.05).

CONCLUSIONS

Given that the MA, SC, A and C parameters behaved similarly in both groups, the repair of composite resins should be elected when clinically indicated, because it is a minimally invasive treatment that can consistently increase the longevity of restorations.

CLINICAL SIGNIFICANCE

The repair of defective composite resins as an alternative treatment to increase their longevity proved to be a safe and effective treatment in the long term.