Abstract
A new fluoride dentifrice was used on 335 school children for one year and its clinical effect on caries prevention was estimated by means of comparison with the results obtained from a placebo group of 315 children of a neighboring village of similar socioeconomic status and with so close a caries susceptibility at the initial base line examination that the caries extent or prevalence was 1.90 DMFT or 69.9% at the test village, Okura, and 1.98 DMFT or 69.5% at the control village, Sakegawa. NaF and synthetic zeolite were included 0.2% and 45.0% in the test dentifrice but not in the placebo. The fluoride ion activity of test dentifrice decreased somewhat immediately after preparation, but 78% of the initial activity still remained even when it was kept for 60 days at 40°C. The Children brushed their teeth twice a day for one year. The children in the test village showed 38.0% reduction in caries increment on the smooth surfaces and 11.9% reduction in the pits and fissures. These reductions were statistically proved to be significant at the 0.1% and 5% level respectively.
