Performance of resin composite restorations in the primary dentition: a retrospective university-based study

Limited data is available on variables influencing the survival of composite restorations in primary teeth.

This retrospective university-based study assessed the survival and risk factors associated with failures of resin composite restorations performed in primary teeth.

The sample was composed of 961 restorations from records of 337 patients (178 girls and 159 boys) attended in a university dental clinic. The restorations' longevity up to 48 months 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).

Mean survival time was 41.5 months (95% CI: 39.7-43.3), with 70.6% of the restorations surviving after 48 months of evaluation. The overall annual failure rate up to 48 months follow-up was 8.3%. Restorations placed in lower arch had lower survival rate than those in upper arch (HR: 1.82, 95% CI: 1.02-3.28). Restorations involving two or more surfaces had more risk of failure than restorations placed in cavities involving only one surface (HR: 2.55 95% CI: 1.34- 4.83). Girls had less risk of failure in their restorations (HR: 0.43, 95% CI: 0.19-0.96).

Individual and dental variables such as gender, arch type and number of restored surfaces were associated with failure of composite restorations performed in children under daily life clinical environment.