Does refurbishing composites lead to short-term effects or long-lasting improvement?

PURPOSE: To evaluate the clinical performance of refurbished resin composite restorations compared to untreated (negative control) restorations over a period of 10 years. METHODS: 26 subjects (having a total of 52 composite restorations) were recruited. All restorations in the refurbished group showed clinical features rated bravo according to modified USPHS criteria. Untreated restorations were those that had been deemed acceptable (alpha or bravo rated); these were used as controls. Two examiners performed assessments at baseline and during the 5th and 10th years after the intervention. Wilcoxon tests were performed for within-group comparisons, Friedman tests were used for multiple within-group comparisons, and Mann Whitney tests were used for between-groups comparisons. Kaplan-Meier survival curves were calculated, and the Mantel-Cox test was used to compare curves. P < 0.05 was considered statistically significant. RESULTS: In both groups, 10-year scores were significantly different from baseline scores in all clinical parameters except secondary caries. There were no statistically significant differences in the survival analysis of groups (log-rank test, P = 0.376). Refurbishing treatment improved the anatomy, roughness, luster, and marginal adaptation of restorations with a short-term effect, with most properties rated acceptable after 10 years of clinical service. The clinical characteristics were similar for all groups at the 10th year.

Indicators of the risk mechanics for Class-I and Class-II amalgam and composite resin restorations

AIM: To determine indicators of prognosis for mechanical risks of amalgam and composite resin restorations in permanent teeth. METHODS: Thirty-nine adult patients with direct clinical, photographic, radiographic and model examinations. A total of 256 restorations were classified as "not satisfactory," with Bravo or Charlie values according to the modified Ryge /USPHS criteria. The total "n" was divided into Bravo and Charlie groups according to the value obtained in the "marginal adaptation" parameter. Each of the groups was sub-divided by the type of material (amalgam and composite resins) and the class: occlusal (O) and proximal (MOD). RESULTS : Comparing the Bravo and Charlie groups, the statistically significant indicators were: the mesiodistal dimension (p=0.037), the distal isthmus (p<0.05), the average of the isthmuses (p<0.05), the distal (p<0.05) cavity depth, and the average depth of the MOD (p<0.05) cavities. It was concluded that the type and the class of the restoration are not indicators for sampling. CONCLUSIONS: With regard to the design of the cavity preparation, the valid mechanical risk indicators include the mesiodistal dimension, the distal isthmus, the average of the isthmuses, the depth of the distal cavity and the average depth of the MOD cavities. A simple clinical assessment does not provide sufficient information to establish the indicators for mechanical failure risk of restorations...