Indirect resin-bonded fibre-reinforced composite anterior bridge: a case report.

In recent years fibre-reinforced resin composites (FRCs) have gained increasing acceptance in mainstream prosthodontics as viable alternatives to alloy-based restorations. A combination of good aesthetics and fracture toughness validates their use in a diverse range of clinical applications. In this case report an indirect resin-bonded fibre-reinforced composite anterior bridge incorporating a novel design is described. At 24-months recall the prosthesis was problem free and the patient was very happy with the treatment outcome. While definitive long-term data about their clinical performance is scarce, fibre-reinforced resin composite prostheses appear to have a worthwhile role in the conservative treatment of short edentulous spaces.

Predictions of resin-bonded bridge survivals, comparing two statistical models.

The purpose of this study was to compare the predictive accuracy of the standard Weibull distribution model with that of a modification, or mixture model, for resin-bonded etched-metal bridge survivals. A total of 189 bridges placed in adult patients treated by students and staff at a teaching hospital was evaluated over periods of up to 8 years. Survival predictions based on the actual survival data accumulated in 1989 were compared with the later survival data updated in 1992. Comparison of the two fitted Weibull predictive curves with the life table survival estimates from the 1992 updated data demonstrated clearly the improved accuracy of the mixture model for predicting survivals of the resin-bonded bridges in this study.

Post-insertion sensitivity with a bonded etched cast metal prosthesis. Case report.

An interesting case of post-insertion sensitivity in a patient who had an etched cast metal prosthesis (Maryland Bridge) cemented with a recently marketed resin luting agent is discussed. This case report draws attention to the fact that despite the relative conservatism and simplicity commonly associated with abutment tooth preparation for resin bonded prostheses, dentine exposure should be avoided if possible to reduce the potential for chemical irritation of the pulp by components of the resin luting system.

A retrospective clinical evaluation of resin-bonded bridges inserted at the Adelaide Dental Hospital.

The clinical performance of resin-bonded Rochette and Maryland bridges inserted by various operators at the Adelaide Dental Hospital is reported. Thirty-four Rochette bridges (30 anterior, 4 posterior) and 228 Maryland bridges (150 anterior, 78 posterior) were assessed. Clinical data were compiled on types of bridge failure, factors influencing bridge retention, and the effects of the prostheses on abutment teeth and supporting tissues. The failure rate for Rochette bridges over 6 years was 75 per cent with a median survival of 2.14 years. Debonding occurred in 70 per cent of bridge failures. The failure rate for Maryland bridges over 5 years was 42 per cent with a median survival of 2.60 years. Pontic fracture (29 per cent) and debonding (20 per cent) were the main failures observed. Porcelain pontics performed significantly better than the processed hybrid resin pontics (P < 0.01). The main reasons for debonding included occlusal stresses, non-retentive bridge designs and resin cement failure. A life-table analysis showed no significant difference in the overall cumulative survival rates between Rochette and Maryland bridges. Bridge design and the choice of pontic material and resin cement emerged as significant factors influencing the success rate of the bridges examined.

A microscopic examination of bond surfaces in failed electrolytically etched cast metal fixed prostheses.

The aims of this investigation were to examine the patterns of resin cement failure between debonded electrolytically etched (Maryland) bridge retainers and their respective abutment teeth and to determine if the clinical assessment of bond failure corresponded to the types of failure observed in the scanning electron microscope. Twenty-eight (18 anterior and 10 posterior), debonded bridges were examined. The results indicated that the classification of bond failures at the clinical level did not correspond to the SEM assessments of failure. It appeared from the specimens examined that loss of retention occurred as a result of resin failure within the cement layer close to the enamel-resin interface. Only one metal retainer specimen showed a small area of resin-metal failure. There appeared to be no differences in the patterns of resin failure between anterior and posterior bridges. The observations also indicated that the resin cements used for bridge cementation adhered well to electrolytically etched retainer surfaces.

A laboratory investigation of colour changes in two contemporary resin composites on exposure to spices.

BACKGROUND: The aim of this study was to evaluate colour stability upon exposure to spices of a nano-filled and a micro-hybrid resin composite finished either with Sof-Lex™ discs (SLD) or against plastic strips (PS). METHODS: Forty cylindrical specimens of 3 mm thickness were fabricated from Filtek Supreme XT ™ (FS) and Gradia Direct X™ (GD). The top surface of each specimen was polished with SLD while the bottom surface was finished against PS. All samples were immersed in staining solutions (0.1% weight turmeric, paprika and tamarind) and distilled water at 37 °C. Colour after 0, 24, 72 and 168 hours of immersion was recorded with a reflection spectrophotometer using CIE L*a*b* parameters and the results were statistically analysed with repeated measures of ANOVA and Bonferroni post hoc tests. RESULTS: Among all the staining solutions tested, the highest colour deviation was obtained in the turmeric group. FS finished against PS showed significantly more colour changes compared to specimens polished with SLD, while GD finished against PS were found to be more resistant to colour changes. CONCLUSIONS: Within the limitations of this study all the spices tested have the potential to stain resin composites with turmeric causing the most significant discolouration. Micro-hybrid and nano-filled resin composites appeared to respond differently to staining by spices when either finished with PS or polished with SLD.