Dental caries and dental fluorosis according to water fluoridation among 12-year-old Brazilian schoolchildren: a nation-wide study comparing different municipalities

Aim: To test the correlation among dental caries, dental fluorosis, and the percentage of municipalities with optimal fluoridated water among Brazilian 12-year-old schoolchildren. Subjects and methods: An ecological study was performed using primary data from the latest Brazilian Oral Health Survey. The units of analysis were the 26 states plus the Federal District of Brazil (n = 7328 schoolchildren). Dental caries was diagnosed according to the DMFT criteria and dental fluorosis according to Dean’s Index. Descriptive and analytical statistics (p < 0.05) were performed. Google My Maps® was used to display data by state. Results: Mean DMFT ranged from 1.06 to 4.81 between states, whereas the prevalence rates of dental caries and dental fluorosis ranged from 37.3 to 78.2% and from 0 to 45.8% between states, respectively. In Brazil, 60.25% of the municipalities have an optimal fluoridated water supply. The percentage of municipalities with an optimal fluoridated water supply in each state ranged from 0 to 97.4%. Dental fluorosis was negatively correlated with mean DMFT (r = − 0.645; p < 0.001) and with dental caries (r = − 0.678; p < 0.001). The percentage of municipalities with optimal fluoridated water was negatively correlated with dental caries (r = − 0.678; p < 0.001) and positively correlated with dental fluorosis (r = 0.668; p < 0.001). Conclusion: Lower prevalence of dental caries was found with the increasing percentage of municipalities with optimal fluoridated water and with the increasing prevalence of dental fluorosis. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature.