Survival characteristics of composite restorations in primary teeth

This retrospective study analyzed restoration survival of composite fillings in children with at high caries risk in relation to age, sex, operator, tooth type, filling extension, and material used.

Among 667 children treated in 2004-2012 in a university setting without sedation or general anesthesia, 2388 composite fillings were included. Relevant data from regular recall intervals were retrieved from patients' records. Either total-etch or a self-etch adhesive combined with flowable and/or (nano)hybrid composite was used. The Kaplan-Meier estimator and Cox proportional hazard analysis with backward elimination model were applied for survival analysis.

For the observation period of 8 years (mean 1.7 years), the cumulative failure rate was 17.2 % with annual failure rates of 10.0 %. In 8.8 % of the cases, fillings failed due to secondary caries. In 8.3 % technical failure due to total filling loss, loosening, marginal gaps, or tooth fracture occurred. Tooth type, filling extension, age, operator, dental dam, and type of adhesive were significant for survival (p < 0.05).

Filling survival was comparably lower to composite restorations observed in prospective clinical studies on permanent teeth and other tooth-colored restoratives used in primary teeth. Due to the very high caries risk and young age of the population, frequent loss due to secondary caries was observed. With respect to the high caries risk, composite restorations can be used to treat carious primary teeth, though a strict caries prevention regimen should be followed to minimize restoration failure.

Filling loss of composites in the primary dentition is associated with secondary caries on the long term.