[The caries occurrence in 7- to 12-year-old schoolchildren in Switzerland. The results of a country-wide survey 1987-89].

Between 1987 and 1989, a random sample of school children aged 7 and 12 years in Switzerland was drawn. In the first stage, districts were chosen. Within the districts, 12 children in the two specified age groups were selected. In addition, Switzerland was subdivided into two strata. The children of stratum 2 had consumed fluoridated salt since birth while those of stratum 1 had only done so during the preceding 4 to 5 years but had benefitted since the age of 5 to 7 from dental health education programs using fluorides at school. The oral examinations were carried out according to the methodology of the World Health Organization. Attendance was 94% (1115 children). 47% of the seven-year-old children were caries-free, and the average dmft was 2.20 (95% confidence limits at 1.87 and 2.52). The average dt was 1.06. These children had an average DMFT of 0.40, with 77% having DMFT = 0. At the age of 12, the average DMFT was 2.03, with confidence limits at 1.73 and 2.33. On average, they had 0.45 DT and 38% of them were caries-free (DMFT = 0). There were only minor differences between the 2 strata. These results agreed well with the data from 6 local surveys carried out during 1987 to 1989. When compared with the majority of European countries, caries experience of Swiss children was fairly low.