Comparison of dental fluorosis and caries in primary teeth of preschool-children living in arid high and low fluoride villages.

The aim of this study was to determine the degree of fluorosis in the primary dentition and the accompanying caries patterns in groups of preschool-children in high and low fluoride areas. Among 331 coloured children, aged 1-5 years, living in an area with water F concentrations ranging from 2.2 to 4.1 parts/10(6), 82% were caries free and the dmft values ranged from 0 to 15 with a mean dmft of 0.8 +/- 2.1. Varying degrees of fluorosis in the primary teeth were present in 50.6% of the children. In 177 coloured children of similar ages from an adjacent area with 0.2 parts/10(6) F in the drinking water the dmft values ranged from 0 to 20 with a mean dmft of 5.4 +/- 5.8. Only 28% of the children were caries free. None of the children in this area had fluorosis. The caries prevalence was significantly higher in the low fluoride area than in the high fluoride area. The degree of fluorosis found in the primary dentition in the children from the high fluoride area was higher than had been anticipated and was accompanied by a very low caries prevalence.