Avaliação dos fatores que influenciam a substituição de restaurações de amálgama por resina composta em dentes posteriores ao longo da vida: um estudo numa coorte de nascimentos

Abstract

Direct restorations are still the most frequently method used for the treatment of the sequelae of dental caries. Among the materials used for this purpose, the amalgam was the most used during the twentieth century and its use showed broad decline in recent decades mainly due to increase on esthetic demand and the absence of adhesion to tooth structure. With the improvement of adhesive systems, resin composites have become the materials of choice for professionals and patients, mainly due to high aesthetics provided by them. Replacement of amalgam for composite resin has been a common practice and this is due, in large part, to search for highly aesthetic patterns by patients. Thus, the aim of present study was to evaluate the occurrence and risk factors for replacement of amalgam posterior restorations for composite resins in individuals from 24 to 31 years old, in southern Brazil. A representative sample of all 5914 births in 1982 in Pelotas was prospectively investigated, and the posterior restorations were accessed at 24 (n=720) and 31 years of age (n=539). Individual-level variables (level 2) including demographic, socio-economic, oral health and dental service characteristics were collected from different waves of the cohort. Tooth-level variables (level 1) included dental group, estimated time in mouth and number of surfaces of restorations. A total of 246 individuals presented 718 amalgam restorations at 24 years. The occurrence of replacement in 7 years was 18.9%. Multilevel Poisson regression models showed that black people presented a lower risk for replacement of amalgam restorations for composite resin compared with white individuals (IRR – 0.39 (0.16 – 0.95)). The increase on educational level at age 31 was associated with increased risk for replacement of amalgam restorations. Individuals with 12 or more years of education presented more than four-fold risk to have their restorations replaced. Considering tooth-level variables, amalgam restorations with two or more surfaces at age 24 showed an IRR 2.80 times greater for replacement compared with those with only one surface. Both individual and tooth-related factors play a key role in choosing for replacement amalgam fillings by composite resin. Furthermore, substitution of amalgam restorations for composite resin in posterior teeth was a common procedure, even with a questionable aesthetic value.