AbstractThis follow‐up of the oral health of children and young adults in Espoo, Finland, has been carried out using annual check‐ups done by dentists at the Espoo Health Center. There was about 80% participation in municipal dental care by 3‐ to 18‐yr‐olds. Each age group included 1700–2300 individuals. The DMFT‐index for 12‐yr‐olds was 6.9 initially and only 2.2 at the end of the 12‐yr follow‐up. The reduced DMFT and increased number of clinically caries free children is probably the cumulative effect of various preventive measures adopted during the follow‐up period. The proportional influence of ea