Epidemiological study on dental fluorosis and dental caries prevalence in communities with negligible, optimal, and above-optimal fluoride concentrations in drinking water supplies

Abstract

The prevalence of dental caries and dental fluorosis was assessed in 5,107 children (2,669 boys and 2,438 girls) aged 6 to 16 years who were lifelong residents of Shenkang Hsiang. The drinking water in the various villages in this area contains negligible, optimal, and above-optimal concentrations of natural fluoride. The prevalence of caries in the optimal fluoride areas was 10.7% lower than in the negligible fluoride area. In the above-optimal fluoride areas, even greater protection from caries was evident. Caries protection was compromised, however, in children with severe fluorosis. The effect may result from food, debris, or plaque being entrapped in the hypoplastic defects of severely fluorosed enamel. Data from children residing in the optimal and above-optimal fluoride areas show that older children are affected more by fluorosis than younger children, according to the Tooth Surface Index of Fluorosis. The relevant variables associated with secular changes in the prevalence of fluorosis are explored. Of the 14 communities studied, chyuarnshing, Dahturng, and Haaiweei, according to the Community Fluorosis Index, represent a medium fluorosis problem, while Dihngsing and Shehgun represent a slight public health fluorosis problem. The remaining communities have no public health fluorosis problem.