作者采用含镧（Ｌａ）、铈（Ｃｅ）、氟（Ｆ）的脱矿液，在体外模拟口腔ｐＨ循环变化的环境中对离体人牙根面进行抑制脱钙的实验研究，并采用化学及能谱分析手段，对Ｌａ，Ｃｅ，Ｆ在根面的抑制脱钙作用进行定量分析，结果显示，这三种微量元素对根面均有明显的抑制脱钙作用，但下较Ｌａ、Ｃｅ的抑制作用强。该研究还从晶体物理化学角度对Ｌａ、Ｃｅ、Ｆ的抑制脱矿作用的机理进行探讨。 In this paper, the authors studied the inhibitory decalcification of the in vitro cultured human dental root surface with the demineralized solution containing lanthanum (La), cerium (Ce) and fluorine (F) in an environment simulating oral pH cycle changes. The results showed that all the three trace elements inhibited the decalcification on the root surface obviously, but the content of La, Ce and F was lower than those of La and Ce Strong inhibitory effect. The study also discussed the mechanism of La, Ce, F inhibition of demineralization from the perspective of crystal physics and chemistry.