Amalgam or composite resin? Factors influencing the choice of restorative material.

ABSTRACT

OBJECTIVES: This study aimed to investigate the patient and tooth factors associated with selection of restorative material in direct posterior restorations in young adults from a population-based birth cohort. METHODS: A representative sample (n=720) of all 5914 births occurring in Pelotas in 1982 were prospectively investigated, and posterior restorations were assessed in 2006, when the patients were 24 years old. Tooth-related variables (individual level) included restorative material (amalgam or composite), type of tooth, size of cavity, and estimated time in mouth. Data regarding demographic and socio-economic characteristics, oral health, and service utilization patterns during the life course were also assessed (contextual level). RESULTS: Logistic Regression Multilevel models showed that individuals who have accessed dental services by private insurance by age 15 [odds ratio (OR)=1.66 (0.93-2.95)] and who had a higher dental caries index at age 15 (high DMFT tertile) [OR 2.89 (1.59-5.27)] presented more amalgam restorations in the posterior teeth. From tooth-level variables, the frequency of amalgams decreases with increasing number of surfaces enrolled in the cavity preparation (p<0.001) and was almost 5 times greater in molars than in premolars. CONCLUSIONS: The present findings suggest that variables related to type of dental service, dental caries (higher DMFT index), and cavity characteristics (tooth type, size) determine the choice of dentists for restorative materials. Other individual characteristics such as demographic and socioeconomic status have not influenced this choice. CLINICAL SIGNIFICANCE: This is the first population-based study that assesses the determinant factors for the choice of dentists for composite or amalgam in posterior direct restorations, showing that, independently of socioeconomic and demographic characteristics, type of payment of dental services and clinical factors are associated with this choice.