Caries risk and number of restored surfaces have impact on the survival of posterior composite restorations

Abstract

Data sources: Cochrane Library, PubMed, the Web of Science (ISI) and Scopus.

Study selection: Longitudinal studies of direct class II or classes I and II restorations in permanent dentition of at least five years duration, a minimum of 20 restorations at final recall and the original datasets available were considered. Only English language studies were included. Two reviewers screened titles independently.

Data extraction and synthesis: Multivariate Cox regression method to analyse the variables of interest and hazard ratios with respective 95% confidence intervals were determined. The annual failure rate (AFR) of the investigated restorations and subgroups was calculated.

Results: Twelve studies, nine prospective and three retrospective were included. A total of 2,816 restorations (2,585 Class II and 231 Class I restorations) were included in the analysis. Five hundred and sixty-nine restorations failed during the observation period, and the main reasons for failure were caries and fracture. Regression analyses showed a significantly higher risk of failure for restorations in high-caries-risk individuals and those with a higher number of restored surfaces. The overall annual failure rate at five years and ten years was 1.8% and 2.4% respectively. The rates were higher in high-caries-rate individuals at 3.2% and 4.6% respectively.

Conclusions: The conclusion of the present meta-analysis of 12 clinical studies based on raw data is that caries risk and number of restored surfaces play a significant role in restoration survival, and that, on average, posterior resin composite restorations show a good survival, with annual failure rates of 1.8% at five years and 2.4% after ten years of service.