[The caries incidence in schoolchildren in the Canton of Glarus 13 years after the introduction of highly fluoridated salt].

Addition of 250 ppm fluoride to domestic salt and salt used by bakeries was begun in 1974-1976 in the Canton of Glarus. The caries examinations revealed a rapid decline of DMFT averages in the four age groups (8, 10, 12, 14 years) by 71 to 78 percent from 1974 to 1987. DMF counts in fissures and pits also decreased by 61 to 80%. In the primary dentition, the number of sound teeth and of sound approximal molar surfaces increased. The average fluoride levels in urinary spot specimens were 0.36 ppm in 1974 and varied between 0.74 and 0.80 ppm from 1979 to 1987. In autumn 1982 toothbrushing exercises with fluoride preparations were introduced. They should have been carried out two to six times a year but were discontinued in 1983 and 1984 in part of the communities. This educational program therefore had little effect on the total reduction, the main decline having occurred from 1974 to 1983. The reduction from 1974 to 1987 was too high and too rapid to be exclusively due to the fluoride in salt but other factors changed little. The percentage of fluoride dentifrice rose only slightly and Swiss averages of sugar and sweet consumption remained almost stable from 1976 to 1987.