DENTAL-CARIES AND DENTAL FLUOROSIS AT VARYING WATER FLUORIDE CONCENTRATIONS

Objectives: The purpose of this study was to investigate the relations hips between caries experience and dental fluorosis at different fluor ide concentrations in drinking water. The impact of other fluoride pro ducts also was assessed. Methods: This study used data from the 1986-8 7 National Survey of US School-children. fluoride levels of school wat er were used as an indicator of the children's water fluoride exposure , The use of fluoride drops, tablets, professional fluoride treatments , and school fluoride rinses were ascertained from caregiver questionn aires. Only children with a single continuous residence (n = 18,755) w ere included in this analysis. Results: The sharpest declines in dfs a nd DMFS were associated with increases in water fluoride levels betwee n 0 and 0.7 ppm F, with little additional decline between 0.7 and 1.2 ppm F. Fluorosis prevalence was 13.5 percent, 21.7 percent 29.9 percen t, and 41.4 percent for children who consumed <0.3, 0.3 to <0.7, 0.7 t o 1.2, and >1.2 ppm F water. In addition to fluoridated water, the use of fluoride supplements was associated with both fewer caries and inc reased fluorosis. Conclusions: A suitable trade-off between caries and fluorosis appears to occur around 0.7 ppm F. Data from this study sug gest that a reconsideration of the policies concerning the most approp riate concentrations for water fluoridation might be appropriate for t he United States.