The timing of the placement of first fillings because of caries on different permanent tooth surfaces was determined at three health centers in Finland. The 927 subjects analyzed were born either in 1970–71 or in 1980–81. Basically, two different types of filling placement site were identified: 1) fissures and pits and 2) proximal and smooth surfaces. In some fissures and pits a‘post-eruptive step’—that is, fillings placed in the year of emergence—was observed. This step had decreased markedly in the cohort born in 1980–81. The curves plateaued (retardation phase) at 50–60% for the occlusal surfaces in first molars for the children born in 1970–71 and at 20–30% for the younger cohort. The time without any filling varied from 1 to 7 years on smooth surfaces, and some surfaces remained totally filling-free. The filling placement curves followed the pattern of caries attack and can thus be used as an indicator of dental health.