Abstract— Three groups of men aged 19 to 22 years were examined. Group A was regarded as control, group B was treated topically with stannous fluoride solution every 6 months, group C received a gel for brushing once a week. All the subjects were re‐examined after 6, 12, 18,24,30 and 36 months and DMFS scores were analysed. In the end of the trial 639 teeth from 213 participants were evaluated in vivo for enamel solubility rates by the CRT test. After three years of treatment both examinations disclosed that the gel was more effective in dental caries inhibition and reduction of the enamel solubility in acids, than stannous fluoride solution.

DMFS increments were determined in 1286 military cadets (19-20 yr old), at 6-monthly intervals during an 18-month clinical study. The cadets were randomly divided into two groups. The test group (n = 787) brushed their teeth with an amine fluoride gel for 5 min once weekly in an unsupervised manner. The control group (n = 499) as well as the test group used a fluoride-free dentifrice twice daily. In both groups, motivation in oral hygiene was given before commencing the study. The cadets in the test group had a 41% lower DMFS increment compared to the cadets in the control group.