A total of 1345 elementary schoolchildren from grades 1-3 (aged 7-9 years) were examined and treated by community health center dentists during 1975-1977. The combined effect of fissure sealing and topical fluoride therapy with 2% NaF gel resulted over the 2 years in an increase in the proportion of caries-free permanent first molars from 50% to 81% in the 1st grade. The mean DMFS scored from the same teeth decreased from 2.8 to 0.8. In the age group born in 1968 the increment of new carious surfaces was 0.28 DFS/year with sealing and 1.13 DFS/year without.