A three-year study of the effect of a sodium fluoride-silica abrasive dentifrice on dental caries.

The purpose of this study was to determine if a 0.243% sodium fluoride-silica abrasive dentifrice provides greater anticaries efficacy than a 0.4% stannous fluoride-calcium pyrophosphate abrasive dentifrice. A sample of 1,824 schoolchildren was randomly assigned to either the sodium fluoride dentifrice or the stannous fluoride dentifrice and examined clinically and radiographically for dental caries initially and after one, two, and three years of dentifrice usage. Two examiners independently examined each of the subjects for dental caries. After three years of ad libitum dentifrice usage, the results for both examiners showed that the group brushing with the sodium fluoride dentifrice had significantly lower DMF tooth and DMF surface increments than the group brushing with the stannous fluoride dentifrice. The percent reductions for DMF teeth were 14.8% and 10.5%, and for DMF surfaces 16.4% and 13.1% for the two examiners, respectively.