[Decline of caries prevalence in Swiss military recruits between 1970 and 1996].

In 1996, 416 military recruits (aged 20.4) were dentally examined. The mean DMFT based on clinical findings was 4,8 (including extracted premolars). The mean DMFT based on clinical and radiological findings was 5.3 (DT=l.2; MT=0.4: almost all of them premolars; FT=3.7. 13% of the recruits were caries-free (DMFT=0). On average, 8.7 affected sites (DFS) were counted; 1.4 were untreated (DS). The caries declined by 70% (DMFT) between 1970 and 1996 and by 46% (DMFT) and 54% (DFS) respectively between 1985 and 1996. In the latter period of time, the mean number of untreated lesions (DS) decreased by 71%, in approximal surfaces of molars and premolars even by 78%. The ratio FS/DFS was 51% in 1985 and 71% in 1996,. This means an improvement in restorative care. 56% of all DFS were found in pits and fissures, 36% in approximal surfaces of molars and premolars. 62% of all untreated lesions (DS) were observed in approximal surfaces of molars and premolars; this percentage was 83% in 1985. The estimated caries increment between age of 15 and 20 was approximately 1.6 DFS/year in the early eighties and 1.3 DFS/year in the early nineties. In 1996 , the former difference in caries prevalence between the recruits from the Canton of Vaud and those from other Western Cantons did not persist. This is probably due to an alignment of the nation-wide supply with fluoridated salt since 1983.