Reactions of Tin (II) and Fluoride Ions with Etched Enamel

Abstract

Acid-etched but otherwise sound and uniform samples of human incisor enamel were treated by brushing with sodium fluoride or tin (II) fluoride solutions for various times at different concentrations and pH''s. After treatment, the samples were exposed to strong acid to dissolve specific thicknesses of enamel. The acid solutions, were analyzed chemically for tin (II) or fluoride ions. The experiments support the following conclusions. Both tin (II) and fluoride reacted with enamel much more rapidly during the 1st few minutes of brushing than they did afterward. Fluoride taken up by enamel from either sodium fluoride or tin (II) fluoride solution was found at appreciable depths in the enamel. Most of the tin (II) from tin (II) fluoride solution was laid down as a uniform coat on the surface or slightly within the enamel.