Feagin F, Thiradilok S
J Oral Pathol. 1979 Feb;8(1):23-7. doi: 10.1111/j.1600-0714.1979.tb01619.x.
Labial surfaces of bovine incisor enamel, after weak acid demineralization, were exposed for 24 h in solutions that contained trace levels of calcium as 45Ca, 0.4 mM NaF, and 1.0 mM MgCl2 at pH 7.0. The solutions approached saturation with apatites in the absence of NaF, and saturation with fluorapatites in the presence of 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. These results indicated that magnesium in oral fluids and tooth minerals may promote caries.
牛切牙釉质的唇面在弱酸脱矿后，于pH值为7.0、含有痕量钙（以45Ca形式存在）、0.4 mM氟化钠和1.0 mM氯化镁的溶液中暴露24小时。在不存在氟化钠的情况下，这些溶液接近磷灰石饱和状态；在存在氟化钠的情况下，接近氟磷灰石饱和状态。氟化钠极大地增加了45Ca的交换。氯化镁减少了45Ca的交换，但对表面矿物质中的氟离子交换没有影响。在随后暴露于pH值为4.5的10 mM乙酸中时，氯化镁降低了而氟化钠增加了交换后的表面矿物质的耐酸性。这些结果表明，口腔液体和牙齿矿物质中的镁可能会促进龋齿。
