Methods: A representative sample (n = 720) of all 5,914 individuals who were born in Pelotas in 1982 was prospectively investigated, and posterior restorations were assessed at 24 yr-old. Exploratory variables included demographic and socio-economic, oral health and service utilization patterns during the life-course. Tooth related variables (type of tooth, material, size of cavity) were also analyzed. Logistic Regression Multilevel analysis with hierarchical models were used for data analysis considering two level of data organization 1)Tooth-Level variables (level 1); and 2) Personal-Level variables (level 2).
Results: Restorations were observed in 503 (69.9%) of individuals at age 24. The overall failure rates for composite and amalgam were 9.36 and 12.20, respectively. Restoration or tooth fracture was the main reason for failures [54.9% (48.3-61.4)], followed by dental caries [17.0% (12.4-22.4)]. Multilevel analysis showed that individuals who were always poor from birth to age 23 [Odds Ratio (OR) = 2.19 (1.24-3.85)] were associated with failure in posterior restorations even after adjusted for tooth level variables. In addition, caries presence at age 15 (high DMFT tertile) [OR 1.95 (1.25-3.03)] and cavities that involved with more surfaces involved [OR 30.92 (11.82-80.90)] were associated with the outcome. Type of tooth, restorative material and estimated time in mouth were not associated with restoration failures.
Conclusions: These results show that socioeconomic characteristics of the individuals during the life-course also play an important role in posterior restoration failures, reinforcing the need to reduce inequalities as a major topic of oral health.