The present study, which is a repeat of a 1980 study, compares the dental treatment needs of 5, 10, and 15-yr-old life-time residents of a fluoridated town (Stranraer) and non-fluoridated town (Annan). Although fluoridation ceased in July 1983, the cost of all dental treatment in 1986 was 57% lower for 5-yr-olds in the fluoride area compared with the non-fluoride one. The corresponding differences in costs for 10- and 15-yr-old groups were 36% and 63%, respectively. Comparison with the 1980 results showed a 21% drop in the cost of all treatment for 5-yr-olds in Annan and a 4% drop in 10-yr-olds. The corresponding comparison for Stranraer 5-yr-olds showed a 43% reduction in the cost of all treatment. The 10-yr-old group in Stranraer showed a 21% increase in the cost of all treatment and a 115% increase in the cost of restorations for caries. The implications of these findings and the possible link with the cessation of water fluoridation are discussed.