All field studies have unequivocally reported significant reductions in dental caries occurrence associated with the use of chewing gum containing xylitol. No other xylitol products besides chewing gum have so far been tested in field trials. A 5-year follow-up study with 2- or 3-year xylitol consumption periods began in Estonia in 1994 with 740 10-year-old children in 12 schools at baseline examinations. For the study, 3 clusters each including 3-5 schools were formed on the basis of baseline caries experience. The products were used under the supervision of the teachers 3 times per day during school days but not during weekends or during the 3-month summer holiday. The daily dose of xylitol was 5 g in all groups. The children were examined every year in September by two experienced clinicians. Dental caries was recorded according to WHO criteria. After 3 years, all xylitol groups showed a highly significant 35%-60% reduction in caries incident, compared with the corresponding control groups. The differences between candies, between candies and chewing gum, and between 2- and 3-year users in the xylitol groups were non-systematic, indicating no trends between the groups. The results suggest that not only xylitol chewing gum but also xylitol candies are effective in caries prevention, and that a school-based delivery system seems to offer a practical way to distribute and control the use of the xylitol products.