Is neighborhood income associated with untreated dental caries irrespective of family income?

Abstract

Objective: To assess the status of untreated dental caries in adolescents exposed to different conditions of family and neighborhood income.

Materials and methods: This cross-sectional study included a representative sample of 1197 15-19-year-old adolescents attending high schools from Santa Maria, southern Brazil. Data collection included a questionnaire and clinical examination (DMFT index). Neighborhood mean income was collected from official sources. The main predictor variable was a combination of household income and neighborhood mean income resulting in four categories: low household income/low neighborhood income, low household income/high neighborhood income, high household income/low neighborhood income, or high household income/high neighborhood income. The outcome was untreated caries (number of teeth with dentin cavities or residual roots). Multilevel Poisson regression analysis was used to assess the association between predictors and untreated caries. Rate ratio (RR) and 95% confidence intervals (CI) were estimated.

Results: The prevalence of untreated dental caries was 26% (n = 312), with a mean (± standard deviation) of 0.47 (± 1.05) teeth. Adolescents with low household income living in areas with low neighborhood income had the worse caries scenario. Compared with them, those classified as low-income households residing in high-income neighborhoods had 37% lower rate of untreated dental caries (adjusted RR = 0.63; 95%CI = 0.44-0.89). No neighborhood effect was detected among adolescents of more affluent families.

Conclusions: Neighborhood income contributed to the rate of untreated dental caries over and above household income among adolescents with low household income only.

Clinical relevance: Improving living conditions in disadvantaged neighborhoods may positively impact the oral health of residents, thus reducing oral health inequalities.

Keywords: Adolescence; Dental caries; Neighborhood; Observational study; Residence characteristics; Socioeconomic factors.