Igor R. Blum

Teaching of the repair of defective composite restorations in Scandinavian dental schools

Given increased tooth retention into later years of life, dentists face increasing challenges in maintaining teeth with extensive composite restorations. Accompanying the increase in placement of composite restorations in general practice, there has also been increased evidence that repair, rather than replacement, of composite restorations is being increasingly considered as a treatment option. Previous work has demonstrated that such techniques are often underutilised in practice. The aim of this study was to examine contemporary teaching of composite repair techniques in Scandinavian dental schools. A questionnaire was distributed by email to each of the 12 Scandinavian dental schools in late 2010/early 2011. This questionnaire sought information on the undergraduate teaching of composite repair techniques as well as indications and materials utilised for this technique. A 100% response rate was achieved (12 schools). Eleven of the 12 respondent schools indicated that they included the teaching of composite repair techniques within their dental school programme. The most commonly reported indications for the teaching of the repair of direct composite restorations were tooth substance preservation (11 schools) and reduced risk of harmful effects on the pulp (10 schools). The most commonly taught surface treatment was mechanical roughening of the existing composite restoration, including the removal of the surface layer of material, prior to application of fresh composite (11 schools). Overall, the results of this study showed that the teaching of composite repair techniques is established within Scandinavian dental schools. This may influence the practising habits of dentists graduating from these schools when considering treatment options for defective composite restorations.

An in vitro comparison of four intra-oral ceramic repair systems

OBJECTIVES This study evaluated the effect of different surface conditioning methods on the tensile bond strength (TBS) and integrity of the leucite-reinforced glass ceramic (Cerana(®) inserts)-resin composite interface, using four commercially available ceramic repair systems. METHODS Two hundred extra-large Cerana(®) inserts were mechanically treated and stored in artificial saliva for 3 weeks and subsequently randomly assigned to one of the following ceramic repair systems (n=40/group): Group 1, Ceramic Repair(®) (Ivoclar Vivadent, Liechtenstein); Group 2, Cimara(®) (Voco, Germany); Group 3, Clearfil Repair(®) (Kuraray, Japan); Group 4, CoJet system(®) (3M ESPE, Germany); and Group 5, no surface conditioning and no adhesive system applied: the control group. Subsequently, resin composite material was added to the substrate surfaces and the ceramic-resin composite specimens were subjected to TBS testing. Representative samples from the test groups were subjected to scanning electron microscopy (SEM) to determine the mode of failure. The data were analysed statistically using a one-way multivariate analysis of variance and Kruskal-Wallis test at a 95% confidence interval level. RESULTS Surface conditioning with the CoJet(®) system resulted in significantly higher bond strength values (5.2 ± 1.1 MPa) than surface conditioning with the other repair systems (p=0.03). The SEM examination of the failed interfaces revealed that all the specimens examined failed adhesively. SIGNIFICANCE Whilst highest bond strength values were observed with the CoJet(®) system all tested repair systems resulted in relatively weak TBS values and, as a consequence, these repair systems may be indicated only as interim measures.

Factors influencing repair of dental restorations with resin composite

The presentation of patients with dental restorations that exhibit minor defects is one of the commonest clinical situations in the practice of general dentistry. The repair of such restorations, rather than replacement, is increasingly considered to be a viable alternative to replacement of the defective restoration. This paper considers factors influencing the repair of direct restorations, including indications and details of relevant techniques, based on the best available knowledge and understanding of this important aspect of minimal intervention dentistry. Practitioners who do not consider repair before deciding to replace restorations that present with limited defects are encouraged to consider including repair in the treatment options in such situations. The effective repair of direct restorations can greatly influence the rate of descent down the “restorative death spiral”.

The Management of Defective Resin Composite Restorations: Current Trends in Dental School Teaching in Japan

AIM The aim of this article is to investigate the contemporary teaching of the management of defective direct resin composite restorations in dental schools in Japan. METHODS A questionnaire relating to the teaching of the management of defective resin composite restorations was developed and e-mailed to 29 dental schools in Japan in 2010. RESULTS Completed responses were received from 19 of the 29 invited schools (response rate = 66%). Eighteen schools (95%) report that they included the teaching of repair of direct defective resin composite restorations in their dental school programs. Thirteen schools reported that they included both clinical and didactic instruction on the repair of direct resin composite restorations. Fourteen schools did not teach any mechanical roughening of the exposed resin composite restoration surface before undertaking a repair. The most commonly reported treatment was acid etching with phosphoric acid (12 schools). The most commonly taught material for completing repairs was a flowable resin composite (16 schools). CONCLUSION The teaching of repair of defective resin composite restorations is well established within many Japanese dental schools, to a greater extent than in some other regions of the world. The impact of this teaching on subsequent clinical practices in Japan should be investigated. Furthermore, it is concluded that there is a need for much stronger leadership in operative and conservative dentistry, ideally at the global level, to resolve differences in key aspects of operative procedures such as repairs.

The opinions of manufacturers of resin-based composite materials towards the repair of failing composite restorations

Aim To investigate the opinions of manufacturers of resin-based composite (RBC) towards the repair of their materials. Methods Representatives of 20 manufacturers of RBC were electronically mailed a questionnaire seeking information on aspects of the repair of direct composite restorations. Results The response rate was 100%. The findings indicated that although the majority of respondents regarded repair as a viable option for managing failing direct RBC restorations, marked variations were found to exist regarding recommendations for and contra-indications to performing repairs of RBC restorations. Conclusions Within the limitations of the current study, the following conclusions can be drawn: (1) the majority of manufacturers of RBC materials are aware and in favour of repair as opposed to replacement of defective composite restorations; (2) there is a need for manufacturers to produce guidelines for repair of their materials; and (3) there is a need for robust randomised controlled dental practice-based clinical studies in the field of repair of composite restorations.

A survey of undergraduate education in dental implantology in UK dental schools

The aim of this study was to ascertain knowledge on current teaching of implant dentistry in the undergraduate curriculum of Dental Schools in the UK. Information on the teaching modalities, including year of introduction of implant dentistry into undergraduate curriculum, departments involved in teaching, format of teaching, use of adjunctive teaching aids, and types of implant systems used in undergraduate teaching was collected by means of a questionnaire, which was sent to all undergraduate dental schools in the UK. Based on a 100% response rate, the findings indicate that all dental schools in the UK reported that they included dental implantology in their undergraduate curriculum; however there were marked variations in the content and delivery of the teaching.

Repair versus replacement of defective direct dental restorations in posterior teeth of adults.

62 Introduction Direct restorations, in common with all restorations, suffer deterioration (“wear and tear”) in clinical service. The presence of defective restorations or restorations with the clinical diagnosis of secondary caries is one of the most frequent situations encountered by general practitioners. The replacement of restorations constitutes around half of the work performed by general dental practitioners in their practices.1 However, this approach may be regarded as over-treatment, since in most cases large portions of the restorations may clinically and radiographically be considered free of failures.2 Furthermore, restoration replacement invariably results in the acceleration of the ‘restoration cycle,’3 with weakening of the tooth through the unnecessary removal of intact tooth structure in locations often distant from the site of restoration deterioration, and the potential for repeated insults to the pulp. Consequently, the diagnostic finding of an existing restoration as defective is a critical step in treatment planning, and it invariably affects the longevity of the restoration and the restored tooth.

An end to linings under posterior composites

BACKGROUND AND OVERVIEW There is an uncertainty among dentists as to whether to place a lining under a direct posterior composite restoration and, if so, what material or combination of materials to use. In this article, the authors consider the evidence for the placement of a lining under posterior composites of different depths, including indications and contraindications for different lining materials. CONCLUSIONS The available evidence does not support the use of linings under direct, bonded posterior composites, unless being placed in deep cavities for therapeutic reasons. PRACTICAL IMPLICATIONS The best available evidence indicates that dentists can place posterior composites without linings, except for therapeutic purposes, with no adverse effect on postoperative complications, with possible improvements in performance in clinical service, and with efficiency savings in chairside time.

An update on the reasons for placement and replacement of direct restorations

AIM The aim of this study was to review patterns of restoration placement and replacement. A previous study had been carried out in the late 1990s and this study sought to update the literature in this important aspect of dental practice. METHOD Studies based on the protocol of Mjör (1981) were selected. Such studies involved participating dentists completing a proforma each time a patient presented for a new or replacement restoration. RESULTS Twenty-five papers were included in this study, of which 12 were included in the original review. The pre-1998 review reported on the placement of 32,697 restorations, of which 14,391 (44%) were initial placements and 18,306 (56%) were replacements. The new studies included in the post-1998 review reported on an additional 54,023 restorations, of which 22,625 (41.9%) were initial placements and 31,398 (58.1%) were replacements. Therefore, across all studies considered, information is available on 86,720 restorations, of which 37,016 (42.7%) were new placements and 49,704 (57.3%) were replacements. Comparing review periods, there was a reduction in the placement of amalgam restorations from 56.7% (pre-1998 review) to 31.2% (post-1998 review), with a corresponding increase in the placement of resin composites from 36.7% to 48.5%. The most common use of amalgam was seen in Nigeria (71% of restorations), Jordan (59% of restorations) and the UK (47% of restorations). The most frequent use of resin composite was seen in Australia (55% of restorations), Iceland (53% of restorations) and Scandinavia (52% of restorations). Secondary caries was the most common reason for replacing restorations (up to 59% of replacement restorations). CONCLUSION In the years subsequent to the initial review, replacement of restorations still accounts for more than half of restorations placed by dentists, and the proportion of replacement restorations continues to increase. Trends towards the increased use of resin composites is noted in recent years. CLINICAL SIGNIFICANCE Further research is required in this area to investigate changes in the approaches to the restoration of teeth, especially with increased understanding of the concept of restoration repair as an alternate to replacement.

Use of lining materials under posterior resin composite restorations in the UK

OBJECTIVES To investigate opinions on, and current use of lining materials prior to the placement of posterior resin composite restorations by general dental practitioners (GDPs) in the UK. A further objective was to investigate aspects of posterior resin composite restoration placement techniques employed by UK GDPs. METHODS A questionnaire was devised to gain the information sought. It was sent to 500 UK dentists, chosen at random from the register of the General Dental Council. RESULTS Three hundred and fifty four replies were received, which gave a response rate of 71%. Eighty two percent of respondents reported placing lining materials in deep cavities to be restored with resin composite. Regarding moderately deep cavities, half of the respondents indicated a preference to place a lining material, whilst 44% were not sure if a lining was required. The remaining 6% did not respond to the question. Of the respondents, 39% reported that they did not place lining materials in shallow cavities. Regarding techniques for posterior resin composite placement, two-step etch and rinse systems were the most common adhesive bonding systems used (60%). The majority of respondents (80%) reported not using rubber dam when restoring posterior teeth with resin composite. CONCLUSIONS There was considerable confusion about the need to place a lining prior to resin composite restorations placement in moderate depth and shallow cavities, whilst most favoured the placement of a lining in deep posterior cavities. The majority of GDPs may not routinely use rubber dam for the placement of posterior resin composite restorations. CLINICAL SIGNIFICANCE Decision making and operative techniques for cavity linings under posterior composite restorations in moderately deep and deep cavities is contentious among dentists, resulting in a need to generate more convincing, practice-relevant data on the use of lining materials to inform the dental profession.