Caries incidence in adolescents with low caries prevalence after cessation of weekly fluoride rinsing.

The aim of this study was to determine whether cessation of weekly fluoride rinsing leads to an increase in caries incidence in a group of adolescents with low caries prevalence. Sixty randomly selected 12- to 14-year-olds were asked to stop rinsing at school (test group). After 3 years caries increment and caries progression were compared with an age- and sex-matched control group (n = 60), who continued to rinse weekly with a 0.2% sodium fluoride solution. All children in both groups had followed a school-based fluoride rinsing program from the age of 6 years. The mean (standard deviation) caries increment, including only open lesions, during the 3 years was 1.58 (1.73) in the test group and 1.48 (1.80) in the control group. The corresponding figures for incipient lesions were 3.13 (3.63) and 4.03 (4.23), respectively. The mean caries progression was 0.92 (1.34) in the test group and 0.72 (1.03) in the control group. None of these differences were statistically significant. Thus, this study showed that a cessation of weekly fluoride rinsing did not lead to an increase of caries incidence in a group of adolescents with low caries prevalence.