Objectives: The aim of this study was to assess the prevalence of direct restorations in posterior teeth in children aged 12, from a birth cohort, and to test the association between the quality of the restorations and individual variables experienced in the life cycle.

Methods: All live-born children in Pelotas, in 2004, were prospectively investigated and a representative sample was assessed for oral conditions at ages 5 and 12. The outcome was the quality of the restoration (satisfactory/unsatisfactory). Independent variables included socioeconomic, behavioral and oral health characteristics at the individual level and the size of cavity and material at the tooth level. Associations were tested using multilevel logistic regression models.

Results: A total of 1,000 participants and 249 restorations in the permanent dentition were examined. Most of the restorations were composites (73.5%), while only 6.8% were amalgam. After adjusted analyses, children whose parents received information on how to prevent their child from developing caries before reaching 5 years of age had 91.0% less chance of having an unsatisfactory restoration compared to children whose parents never received information (OR = 0.09; 95% CI 0.01-0.59). Also, the chances of presenting unsatisfactory restorations were 5.3 higher in children at high-risk for untreated dental caries in the permanent dentition, in comparison with children at low risk (OR = 5.32; 95% CI 1.07-26.6).

Conclusions: Low-risk for untreated dental caries and having received information on preventing dental caries, reduced the chance of presenting failed restorations, showing that factors related to individuals play an important role in the quality of restorations.