X-ray diffraction analysis of carious dentine treated with stannous fluoride

Abstract

Carious dentine was treated with a 10 per cent stannous fluoride solution for 24 hr at 37 °C and prepared for X-ray diffraction analyses using the powder smear mount technique. It was found that a new crystalline material was produced within the dentinal matrix. Replica experiments using synthetic hydroxyapatite with and without added collagen and reacted with stannous fluoride produced a material identical to that found in the stannous fluoride treated carious dentine. These results indicate that the material was the product of an inorganic reaction and that the organic collagen in carious dentine plays little or no role in this reaction. Additional experiments using synthetic hydroxyapatite and varying solution concentrations and reaction times showed that the crystalline material, most probably a tin phosphate, was produced in less than 5 min. and was independent of solution strength or prolonged exposure to the solution for up to 10 days.