Effects of magnesium and fluoride on ion exchange and acid resistance of enamel

Publisher Website
Google Scholar
Abstract
Labial surfaces of bovine incisor enamel, after weak acid demineralization, were exposed for 24 h in solutions that contained trace levels of Ca as 45Ca, 0.4 mM NaF, and 1.0 mM MgCl2 at pH 7.0. The solutions approached saturation with apatites without NaF, and saturation with fluorapatites with NaF. NaF greatly increased the exchange of 45Ca. MgCl2 decreased 45Ca exchange, but had no effect on F- exchange in the surface minerals. MgCl2 decreased, while NaF increased the acid resistance of the exchanged surface minerals on later exposure to 10 mM acetic acid at pH 4.5. Mg in oral fluids and tooth minerals could possibly promote caries.