A kinetic and morphological study of mineralization of bovine tooth enamel surfaces

A new constant composition method was used to study the kinetics of remineralization of enamel surfaces. The labial enamel surfaces were treated with 20 per cent phosphoric acid, 0.05 M HCl, EDTA (2 per cent, pH 4.0) yielding Type I etched surface and with EDTA (1–2 per cent, pH 7.0) to give a Type II etched surface. Remineralization experiments were made in stable supersaturated calcium phosphate solutions undersaturated with respect to dicalcium phosphate dihydrate and octacalcium phosphate phases, at pH 7.40 and 37 °C. Type I-etched surfaces yielded similar remineralization rates, but these were greater than those for Type II surfaces. Confirmation of hydroxyapatite as the exclusive remineralizing phase was made by various physico-chemical methods. Scanning electron microscopy of the remineralized phase, suggested various sites for remineralization.