Area-level social development and indicators of public dental services in Southern Brazil

This study aimed to test associations between a municipal social development indicator and indicators of public dental services; examine differences in the achievement of public dental services goals between fluoridated and nonfluoridated municipalities; and, quantify contribution of a municipal social development indicator in estimated mean differences in the public dental services indicators between fluoridated and nonfluoridated municipalities.

A secondary analysis of data from 293 municipal dental health services records from Southern Brazil between 2010 and 2015 was conducted. Multivariable log-binomial regression models were fitted to test the associations between municipal Human Development Index (HDI) and multiple public dental services indicators (proportion of public dental health service coverage, the proportion of tooth extraction among all clinical procedures, and monthly participation in supervised tooth brushing). Cut-off points for outcomes were based on state goals for public dental services. Blinder-Oaxaca decomposition analyses were performed to quantify the relative contribution of HDI in the differences in outcomes according to the municipal water fluoridation status.

Municipalities within the lowest tertile of HDI had 66% lower prevalence of having insufficient public dental health service coverage (less than state goals)than those in the highest tertile of HDI (PR: 0.44; 95% CI: 0.24, 0.50). Municipalities with lowest HDI had nearly 30% higher prevalence of failing the state goals regarding the proportion of extraction and supervised tooth brushing (PR: 1.30; 95% CI: 1.20, 1.40 and PR: 1.34; 95% CI: 1.23, 1.45, respectively). Mean public dental health service coverage was higher in nonfluoridated municipalities than fluoridated municipalities, and municipal HDI explained 36% of the total estimated mean difference.

This study found associations between municipal social development and public dental services indicators in Southern Brazil. However, higher HDI was associated with lower public dental health service coverage, lower proportion of extraction and higher coverage of supervised tooth brushing [Correction added on 2 April 2019, after first online publication: In the preceding sentence, the text "but with a higher proportion of extraction and supervised tooth brushing" was changed to "lower proportion of extraction and higher coverage of supervised tooth brushing"]. Municipal HDI contributed significantly towards the gap in public dental coverage between fluoridated and nonfluoridated municipalities, favoring nonfluoridated municipalities. These findings have important policy implications for reducing oral health inequalities as it highlights the interplay between key oral health policies and their distribution according to municipal social development.