Inhibition of Enamel Demineralization by Repeated Treatments with Sodium and Stannous Fluoride Solutions

¹ Research Department, Tufts University School of Dental Medicine, Boston, Massachusetts

The primary purpose of this study was to learn whether frequency of treatment with equimolar, low concentrations of sodium or stannous fluoride, such as might occur in the mouth on using a fluoride-containing dentifrice, would affect the demineralization rate of enamel sections. Practically no difference in the rate of penetration was observed between sections treated once or twice daily with water. All the sections treated with fluoride solution showed less decalcification. This reduction in decalcification was independent of penetration depth. Sections treated twice a day with stannous fluoride solution experienced the least amount of decalcification, amounting to 58 per cent of control at 264 hours. The age of the tooth (twenty to over fifty years) did not seem important in determining the effect of either fluoride solution on the rate, or total penetration, of the acid.