Is water fluoridation effective in reducing inequalities in dental caries distribution in developing countries? Recent findings from Brazil.

Objectives: To assess socioeconomic differences between towns with and without water fluoridation, and to compare dental caries levels among socioeconomic strata in fluoridated and non-fluoridated areas.

Methods: A countrywide survey of oral health performed in 2002-03 and comprising 34,550 children aged 12 years provided information about dental caries levels in 249 Brazilian towns. Socioeconomic indices, the coverage and the fluoride status of the water supply network of participating towns were also appraised. Multivariate regression models fitted the adjustment of dental caries levels and covariates to socioeconomic status and water supply. Inequalities in dental outcomes were compared in towns with and without fluoridated tap water.

Results: Better-off towns tended to present a higher coverage by the water supply network, and were more inclined to add fluoride. Fluoridated tap water was associated with an overall improved profile of caries, concurrent with an expressively larger inequality in the distribution of dental disease.

Conclusion: Suppressing inequalities in the distribution of dental caries requires an expanded access to fluoridated tap water; a strategy that can be effective to foster further reductions in caries indices.