The adoption of xylitol chewing gum in Finland was studied using data from two comparable postal surveys for national samples of 12- to 18-year-olds in 1977 (response rate 79%, n = 2,528) and 1991 (77%, n = 7,672). In 1977 only 12% of this age group used xylitol chewing gum but, by 1991 it had become common (64% of boys, 81% of girls). Daily use increased from 1 to 15% among boys and from 1 to 32% among girls. Use of sucrose chewing gum decreased; in 1991 only 2% used it daily. Daily use of xylitol chewing gum did not vary according to socioeconomic status or level of urbanization. The increase in use of xylitol chewing gum is an example of the positive effect of health education given by a comprehensive, preventively oriented system of dental health care in association with commercial interests.