Nairn Wilson

An Overview of Reasons for the Placement and Replacement of Restorations

Aim Surveys on reasons for the placement and replacement of restorations have been conducted in various countries. The purpose of this paper is to bring together and review the data of 10 such surveys with similar methodology. Method The studies reviewed are all based on the protocol described by Mjör in 1981. Results The surveys reviewed provide data on the reasons for the placement and replacement of a total of 32,777 restorations. Notwithstanding differences between countries, different groups of practitioners and minor variations in methodology, the data included in the selected surveys indicate that everyday clinical practice in Scandinavia, UK and USA during the 1980s and 1990s has involved more replacement than initial restorations, with the ratio of initial to replacement restorations ranging from 1:1.1 to 1:2.4 for amalgam and 1:1.1 to 1:3.8 for composite materials. Primary caries has been consistently found to be the principal reason for the provision of initial restorations of amalgam and composite. The principal reason for the replacement of restorations of amalgam and composite has remained secondary caries as diagnosed clinically. Material failures (marginal degradation, discoloration, bulk fracture and loss of anatomic form) accounted for the replacement of more restorations of composite than amalgam. Recent surveys have reported secondary caries as the principal cause of failure of restorations of glass-ionomer cements and related materials. Conclusions The clinical diagnoses of caries may continue to be found to account for the placement and replacement of most intracoronal restorations. Surveys of the type reviewed provide valuable insight into patterns of provision of dental care and highlight research priorities in relation to direct restorations.

Glass-ionomer Restoratives: A Systematic Review of a Secondary Caries Treatment Effect

It is generally accepted that glass ionomers inhibit secondary caries in vivo, and data from in vitro studies support this effect. The aim of this review was a systematic assessment, from the literature, of clinical evidence for the ability of glass-ionomer restoratives to inhibit secondary caries the restoration margin. Inclusion and exclusion criteria for selection of the review papers were established prior to commencement of the literature search. Papers which conformed to these criteria, and reported on secondary caries as an outcome, were selected (N = 52). Primary and secondary of systematic for use in the assessment of the papers were drawn up. The primary list of 14 criteria was applied to each paper. No paper fulfilled all these criteria, necessitating the use of the secondary measures: (i) a prospective study and (ii) use of an appropriate control. This yielded 28 papers. Tabulation of these papers by occurrence of secondary caries in the glass-ionomer or control groups demonstrated an even distribution between positive and negative outcomes. Valid evidence is to be best obtained from randomized, controlled of sufficient sample size. No conclusive evidence for or against a treatment effect of inhibition of secondary caries by the glass-ionomer restoratives was obtained from the systematic review. There is a need for appraisal of the methods currently adopted for the clinical of glass-ionomer restorative materials, for further development of the methodology to support future systematic reviews.

Clinical evaluation of a posterior composite 10-year report

OBJECTIVE The 10-year findings of one of the studies which comprised the multicentre clinical evaluation of a light-cured posterior composite restorative are reported, with special emphasis on the reasons and timing of failure of restorations included in the study. Effects of the use of rubber dam or cotton rolls and aspiration for isolation at the time of placement are considered. METHOD One hundred Class I and II restorations of the resin composite investigated were placed by a single operator in a group of selected, predominantly young-adult patients under highly controlled conditions, with the use of rubber dam or cotton rolls and aspiration for isolation being determined according to a scheme of randomisation. The restorations were reviewed clinically after 1 week and within 1 month of placement (baseline) and, thereafter, at 6 months, 1, 2, 3, 4, 5, 6 and 10 years using modified USPHS codes and criteria. Epoxy models and photographs were obtained for retrospective analysis. RESULTS After 10 years, 37 restorations were reviewed and 32 restorations were known to have failed. Regarding the reasons for failure, loss of occlusal anatomic form during the first 5 years and loss of approximal contacts near the end of the study accounted for most of the failures. Only two failures were attributed to recurrent caries. Few of the restorations found to be clinically satisfactory at 10 years had retained ideal functional characteristics. Location, Class and size of restoration and the method of isolation were not found to significantly influence 10-year performance and survival. CONCLUSION The actual 10-year failure rate, estimated to have been between 40 and 50% is considered to have been high, notably given the limited incidence of recurrent caries and bulk fracture. However, the findings indicate that certain restorations of the material investigated, despite the use of outdated operative techniques, may be found to perform satisfactorily over periods in excess of 10 years.

Mechanical properties of direct core build-up materials

OBJECTIVE This work was undertaken to measure mechanical properties of a diverse group of materials used for direct core build-ups, including a high copper amalgam, a silver cermet cement, a VLC resin composite and two composites specifically developed for this application. METHODS Compressive strength, elastic modulus, diametral tensile strength and flexural strength and modulus were measured for each material as a function of time up to 3 months, using standard specification tests designed for the materials. RESULTS All the materials were found to meet the minimum specification requirements except in terms of flexural strength for the amalgam after 1 h and the silver cermet at all time intervals. SIGNIFICANCE There proved to be no obvious superior material in all respects for core build-ups, and the need exists for a specification to be established specifically for this application.

The teaching of Class I and Class II direct composite restorations in European dental schools

OBJECTIVES The purpose of this descriptive study was to provide updated data on the teaching of Class I and Class II direct composite restorations in Europe as part of a survey of this aspect of the primary dental curriculum in Europe and North America. METHODS Data on the teaching of posterior composite restorations and related matters were collected by means of a postal questionnaire sent to 185 dental schools known to exist in Europe. Non-respondents were sent a second questionnaire after two months. Further information pertaining to student requirements was sought after six months from all respondents. RESULTS The response ranged from 92% for dental schools in Scandinavia to 40% from dental schools in Southern Europe with an overall response of 56%. All but four of the 104 participating schools were found to teach the use of composites in Class I and Class II, two-surface situations in at least premolar teeth. Contraindications and techniques taught for posterior composites varied within and between the country groupings of Northern and Central Europe. Scandinavia, Southern Europe and Eastern Europe. However, certain consensus views were identified. The experience of adverse biological reactions to the use of resin-based restoratives in European dental schools was found to be limited. CONCLUSIONS Notwithstanding the variation in the response from the four geographic regions investigated and the relatively low overall response to the questionnaire, it is concluded that the data reported indicates that most dental schools in Europe teach the use of composites in selected Class I and Class II situations. However, considerable variation exists both within and between the regions investigated in relation to this teaching. Further research and consensus conferences should be planned to reduce variability across Europe in relation to the contraindications and techniques taught for posterior composites.

Contemporary dental practice in the UK: aspects of direct restorations, endodontics and bleaching.

Objective To investigate, by postal questionnaire, aspects of the selection and use of direct restorative materials, endodontic techniques and approaches to bleaching by general dental practitioners in the UK, and to compare and contrast the findings with those of a related study reported in 2004.Methods A questionnaire comprising 18 questions, each of a number of elements, was sent to 1,000 general dental practitioners in the UK, selected at random from the Dentists Register. Non-responders were sent a second copy of the questionnaire after a period of four weeks had elapsed.Results A total of 662 useable responses were returned, giving a response rate of 66%. Key findings included: dental amalgam was found to be the most commonly used material in the restoration of occlusoproximal cavities in premolar (59% of respondents) and molar teeth (75% of respondents); glass-ionomer cements and related materials were applied extensively in the restoration of deciduous molars (81% of respondents) and for the luting of indirect restorations (67% of respondents); the use of rubber dam was limited, in particular as an adjunct to procedures in operative dentistry (18% of respondents); relatively few respondents used preformed stainless steel crowns, and among the users only occasionally in the restoration of deciduous molars (23%); and bleaching, predominantly home-based (nightguard) vital bleaching (81% of respondents) was widely practised.Conclusion It is concluded that, for the practitioners surveyed, factors other than best available evidence influenced various aspects of the use of direct restorative materials and the clinical practice of endodontics. As a consequence, many of the features of general dental practice revealed in the process of the investigation were at variance with teaching in dental schools. Bleaching, in particular home-based (nightguard), vital bleaching, was provided by >80% of respondents, indicating widespread interest among patients in enhanced dental attractiveness.

Influence of the isolation method on the 10-year clinical behaviour of posterior resin composite restorations.

Abstract The aims of this prospective randomised clinical study were to clinically evaluate a radiopaque, highly filled, hybrid, light-activated resin-based composite for posterior teeth (Occlusin, ICI Dental, Macclesfield, UK and GC Dental, Tokyo, Japan) and compare the performance of restorations placed using rubber dam or cotton roll isolation. One clinician placed 100 (42 Class I and 58 Class II) restorations of the material under investigation. The isolation mode for each restoration was determined randomly: 52 preparations were protected from contamination with cotton rolls and aspiration, and 48 preparations were isolated under rubber dam. At baseline and periodically thereafter (0.5, 1, 2, 3, 4, 5, 6, and 10 years), each composite was evaluated by two practitioners using a modified (USPHS) rating system. After 10 years, 37 restorations were reviewed. The results showed satisfactory clinical performance with and without rubber dam after 10 years. A concern was the number of failures at 10 years due to unsatisfactory proximal contact. The evaluations for the surviving restorations were acceptable but with a large reduction in the percentage with ideal occlusal and proximal anatomy. The 10-year comparison of isolation modes showed no statistically significant differences (Kruskal-Wallis test) for each of the evaluation criteria. Furthermore, survival analysis showed no significant difference between the groups (Mantel-Haenszel method). It was concluded that the 10-year clinical behaviour of the restorations of a posterior composite placed under well-controlled, effective isolation with cotton rolls and aspiration, was not significantly different from the behaviour of restorations placed using rubber dam isolation.

Endodontics in the adult patient: the role of antibiotics.

OBJECTIVES The aim of this study was to review the published work on the indications and efficacy for antibiotics in endodontic therapy. DATA SOURCES Published works in the medical and dental literature. STUDY SELECTION Evaluation of published clinical trials in endodontic and other pertinent literature. CONCLUSIONS Antibiotics are not routinely indicated in the practice of endodontics. Therapeutic antibiotics may be required as an adjunct to operative treatment when there is pyrexia and/or gross local swelling; they are only rarely indicated in the absence of operative intervention. Prophylactic antibiotics may be required for certain patients who are susceptible to serious infective sequaelae.

Current status and rationale for composite inlays and onlays.

Composite inlay systems, now available to the dental profession, are classified and evaluated. Principle motives for their deployment are the aviodance or reduction of in situ polymerisation shrinkage and the optimisation of restoration contour and adaptation. The criteria for placement of direct or indirect composite inlay restorations are critically reviewed in relation to alternative materials and operative procedures. Dimensions of typical molar and premolar inlay cavities are presented and interim guidelines for inlay cavity design are discussed

Age of failed restorations: A deceptive longevity parameter.

UNLABELLED There is pressing need to enhance evidence base in respect of longevity of restorations. Currently, there is lack of appreciation of differences between survival data based on the age of failed restorations as compared to gold standard Kaplan-Meier statistics. OBJECTIVES This study was undertaken to compare and contrast longevity data for a number of data sets. It investigated if restoration longevity, as calculated by the Kaplan-Meier method, is different from longevity according to the median survival time of failed restorations. METHODS Existing clinical datasets of dental restorations and an artificial dataset were used to calculate longevity according to Kaplan-Meier statistics and by means of calculation of median age of failed restorations. RESULTS The findings indicate that median age of failed restorations may be considered as a deceptive measure of restoration longevity. Specially extending the duration of longitudinal studies of restorations apparently leads to higher values for median age of failed restorations. Restorations of materials that tend to exhibit early failures may have lower values for median age of failed restorations, compared to restorations of different materials which tend to exhibit failures later in clinical service, and thereby not giving a true measure of overall restoration longevity. CONCLUSION In absence of all dates of placement and failure for a series of restorations a reliable measure of restoration longevity is not yet available. Kaplan-Meier statistics remains the preferred method of calculating longevity of a group of dental restorations.