Epidemiology of fluorosis and dental caries according to different types of water supplies.

The aim of this article is to investigate the relationship between fluorosis/dental caries in schools, according to the level of fluoride in public water supply. The sample comprised of twelve-year-old daytime students (360) of both genders, attending schools close to the region where they were born. The schools were classified into three groups according to the presence of fluoride in the water supply: 1) fluoridation in the Water Treatment Station-WTS; 2) Direct Fluoridation in Wells-DFW; and 3) Non Fluoridated Areas-NFA. The chi2 and Goodman tests (significance=5%) were used to evaluate the association between the origin of water and degree of fluorosis; percentage of distribution and descriptive measures were used for investigation of the degree of fluorosis. The following outcomes were predominant: presence of dental caries in the entire sample (P<0.05); absence of fluorosis in both genders, for white individuals and subjects living in areas supplied by both DFW and NFA (P<0.05). There was no difference in the severity of fluorosis between the sources of water supply (P>0.05). Dental caries is still an important problem in this population, despite the establishment of preventive measured. The observation of fluorosis in students living in non-fluoridated areas confirms the presence of other sources of fluoride.