Sealant retention varied according to site of the tooth. Figures for intact sealant were particularly low for permanent first molars among first graders and for permanent second molars among sixth graders at the end of three years. Although a large percentage of these teeth needed sealant reapplications, the percentages of teeth that were lost to caries were as low as 12.2% and 12.8%, respectively. Deciduous molars had the best rate (60.9%) of complete retention and also the highest percentage (20.2%) of loss caused by caries. However, in sixth graders, the premolars had the highest percentage (46.7%) of complete retention and, at the same time, the lowest caries rate (5.6%). The sealant retention pattern has remained the same during the three-year period.