Dental caries experience of 16-17-year-old naval recruits related to the water fluoride level in their home town.

Out of 6694 recruits who joined the Royal Navy between September 1979 and February 1981, 1983 (30%) had lived all their lives in one locality. Information on the fluoride level, between 1963 and 1980, in the water supply to each of the recruits' homes was obtained. The examiner recording the dental status of each recruit did not know where the recruit had lived. Some of the information on fluoride levels was imprecise or of variable quality so the final analyses were restricted to 1332 16-17-year-old subjects. The overall mean DMFT for the 1332 recruits was 9.72. There was a consistent fall in caries experience with increasing water fluoride level although the difference between the caries experience of recruits from low and high fluoride areas (about 20% for mean DMFT) was smaller than that observed in other studies. A possible explanation for this smaller difference is that some of the subjects did not receive fluoridated water early in life.