Survival and Associated Risk Factors of Resin-based Composite Restorations in Primary Teeth: A Clinical, Retrospective, University-based Study.

Purpose: This clinical retrospective study evaluated the survival and risk factors associated with failures of resin-based composite restorations in primary teeth.

Methods: A total of 212 restorations in primary teeth from records of 76 high caries-risk children were included. The restorations' longevity for up to six years of follow-up was assessed using the Kaplan-Meier survival test. Multivariate Cox regression analysis with shared frailty was used to evaluate the factors associated with failures (P<0.05).

Results: Mean survival time was 4.3 years (95 percent confidence interval (CI) equals 4.0 to 4.6). The survival of the restorations reached 35.3 percent, up to the sixth year, with an annual failure rate of 18.8 percent. Restorations placed in teeth with pulp treatment had a lower survival rate than those in vital teeth (hazard ratio [HR] equals 2.16, 95 percent CI equals 1.02 to 4.58). Patients who did not use standard fluoride toothpaste had more risk of failure in their restorations (HR equals 6.12, 95 percent CI equals 1.47 to 25.49).

Conclusions: Composite restorations placed in high caries-risk children presented limited survival after six years of follow-up. Standard fluoride toothpaste use was a protection factor, while pulp treatment was a risk factor for restoration failure.