Inhibition of enamel dissolution rates by sodium fluoride and amine fluorides in the presence or absence of strontium ions

The dissolution rates of enamel pellets in acidic buffered solutions of sodium and amine fluorides with or without strontium ions have been studied. The experiments have shown that the rates of dissolution are drastically reduced by fluoride and strontium ions. Synergistic effects of sodium fluoride and strontium ions on the dissolution rate of enamel have been observed. However, there was the additional effect of strontium on inhibition of the dissolution rates in the presence of amine fluorides. The lack in synergistic effect may be attributed to the coating layer of the long-chain amine group on the enamel surface.