Good short-term survival rates for posterior resin composite restorations.

DATA SOURCES: PubMed, the Cochrane Library and the databases of the Centre for Reviews and Dissemination were searched. STUDY SELECTION: Prospective randomised controlled trials (RCTs), clinical controlled trials (CCTs) and observational studies of Class I and/or Class II resin composite restorations with a sample size of more than 40 individuals or teeth and longer than four years follow-up were considered. RESULTS: Eight studies involving a total of 910 restorations in 420 patients were included. Seven of the eight studies were completed by the same research group with follow-up times ranging from four to 12 years. There were 80 failures of restorations in total, ranging from two to 17 per study. A majority of the fractures of the restoration or the tooth and endodontic complications occurred during the first three years of follow-up. Caries occurred later, more than 75% after three years in service. The overall incidence rate for all causes of failure was 1.55 lost restorations per 100 restoration years. Survival rate at four years = 0.93 (95% CI; 0.91- 0.95). One study (74 teeth) provided data at 12 years with a survival rate = 0.86 (95% CI; 0.82;0.89). The most common biological reason for failure (a total of 31 restorations) was secondary caries, with or without fracture of the restoration. The overall quality of the evidence was low. CONCLUSIONS: The overall survival proportion of posterior resin composite restorations is high. The major reasons for failure are secondary caries and restoration fracture, which supports the importance of adequate follow-up time as secondary caries often occurred after three years or later.