[Fluoride excretion in schoolchildren with differing systemic fluoride care].

The aim of the present study was to collect data on urinary fluoride output in 8-16-year old students exposed to either drinking water fluoridation (DWF), or domestic salt fluoridation (DSF). Spot urine samples were collected in the canton of Basel-Stadt (DWF, n = 123), in the canton of Berne (DSF, n = 264), in the county of Davos (DSF, n = 241), and in the city of Winterthur (DSF, n = 40). Furthermore, fluoride concentrations were determined in plasma samples drawn from 33 students from Winterthur. The urinary fluoride concentrations were higher in Basel and Davos (0.62 +/- 0.35 mg/l; 0.61 +/- 0.42 mg/l) than in Berne and Winterthur (0.46 +/- 0.42 mg/l; 0.50 +/- 0.31 mg/l). A relatively high natural fluoride content (0.3 mg/l) in the drinking water explained the difference in urine fluoride concentration between students from Davos and the two other regions with domestic salt fluoridation (Berne, Winterthur). The average fluoride concentration in plasma was 12.7 +/- 3.8 ng/ml. We concluded that, in general, the supply with fluoride consumed with fluoridated domestic salt is close to the level obtained with drinking water fluoridation. However, in areas with very low systemic fluoride supplementation through the drinking water this level might not be reached with salt as the only source of systemic fluoride. Also, the data confirmed the safety of domestic salt fluoridation.