Enamel Lesion Formation with and without 0.12 ppm F in Solution

Abstract

This paper describes the influence of very small amounts of F (0.12 ppm) in a demineralizing solution on lesion formation in bovine enamel at pH = 5. Polished bovine enamel has a very low F content and does not ‘contaminate’ the demineralizing solution with fluoride from the enamel itself. Standardized enamel areas were demineralized for various periods up to 240 h; after a given period the liquid was analyzed for Ca, phosphate and F; the enamel defects formed were investigated by means of microradiography and microscopy. The results show that (1) lesion depth is hardly influenced by the presence of about 0.12 ppm F in the liquid; (2) the amount of mineral dissolved from the enamel is strongly influenced by F; (3) demineralization without fluoride in solution resulted in enamel defects without a surface layer (softened), and (4) demineralization with 0.12 ppm F in solution resulted in subsurface lesions.