Fluoride Intake from Food and Liquid in Japanese Children Living in Two Areas with Different Fluoride Concentrations in the Water Supply

Abstract

The purpose of this study was to estimate the average daily amount of fluoride from the diet ingested by Japanese children of ages susceptible to dental fluorosis in two areas with different fluoride concentrations in the water supply. Thirty-eight children aged 2–8 years participated in a survey of fluoride intake. Twenty-one out of 38 children lived in an area in which the community water fluoride concentration was an average of 0.555 ppm (moderate fluoride area: MFA), and 17 lived in a low fluoride area (LFA), which ranged between 0.040 and 0.131 ppm. To measure the fluoride intake, diets were collected with a duplicate-diet technique. The fluoride concentrations in each sample were measured using the diffusion technique of Taves and the electrode technique. Meanwhile, after clinical examinations for dental caries and fluorosis, 228 subjects aged 13–15 years were selected for analysis from the same communities. The mean DMFT in the MFA was significantly lower than that in the LFA. The severest grade of dental fluorosis observed was ‘very mild’ according to Dean’s fluorosis index in both areas. The total daily fluoride intakes were 0.0252–0.0254 mg F/kg/day in the MFA and 0.0126–0.0144 mg F/kg/day in the LFA. Differences in the fluoride concentration of drinking water in this study were reflected in the fluoride intake from the diet in a typical Japanese diet.