Caries development after termination of a fluoride rinsing program

In a municipality near Copenhagen, Denmark, where fortnightly fluoride rinses with 0.2% neutral sodium fluoride had been performed for more than a decade, 1306 children from kindergarten through 6th grade were stratified by school and grade and randomly distributed into two groups. One group continued the fluoride rinses, the other group had the fluoride solution replaced with distilled water. Both solutions were slightly flavored. 1083 children completed the 3-yr trial. Caries was recorded clinically by the dentists in the municipal dental service using the diagnostic criteria for the Child Dental Health Services, and on bitewing radiographs by one of the authors applying the criteria developed by GRONDAHL et al. Permanent molars and premolars were included in the study. Clinically, caries increment in the two groups was the same with pits and fissures containing 94% of the DMFS. According to the radiographs, caries progression in the water group was higher than in the fluoride group. This difference was statistically significant for the surfaces erupting during the study (P less than 0.05).