氯化镧对人牙釉质人工龋的影响──扫描电镜、电子探针分析

借助体外人工龋方法从形态和内部结构变化上探讨了氯化镧（Ｌａ３＋）对人牙釉质龋的影响。磨片光镜下显示Ｌａ３＋预处理阻抑龋病发展的作用不如氟化钠（Ｆ－），但Ｌａ３＋与Ｆ－先后预处理能明显减轻龋损程度。扫描电镜观察发现Ｌａ３＋及Ｆ－预处理均能在牙面形成覆盖物，但以Ｌａ３＋与Ｆ－先后预处理产生的覆盖物较致密且与牙面结合较紧密。电子探针分析显示Ｌａ３＋处理后釉质表层内钙（Ｃａ２＋）含量明显减少，而Ｌａ３＋显著增加，表明Ｌａ３＋能与Ｃａ２＋发生离子交换反应而进入釉质。这种牙面覆盖物的形成及Ｌａ３＋－Ｃａ２＋交换反应可能是Ｌａ３＋预处理能防龋的关键之一。

The influeuce of Lanthanum Chloride on the progression of the artificial caries in human euamel.

The ability of Lanthanum Chloridc (La) to inhibit the progression of artificial caries in human enamel was studied using light microscopy, SEM and microprobe analysis techniques. The microscopy view of the sections showed the effect of the La(3 ) on artificial caries was not so good as that of sodium fluoride (F) but La(3 ) F(-)pretreatment inhibited the progression of the artificial caries to a certain extent. Different pretreatments all produced surface coatings on the enamel but the surface coatings which were in more intimate contact with the enamel surface of artificial caries were seen after F(-)and La(3 ) F(-) pretreatment.The microprobe analysis revealed the La(3 )could penetrate into the enamel and the La(3 ) of the surface layer of artificial caries was increased but the Ca(2 ) was decreased obviously after the pretreatment of the La. The results suggested that the Ca(2 ) in the surface layer of enamel could be replaced by the La(3 ). It was believed that the surface coatings and the ion exchanges might be the key that the La(3 )could prevent dental caries.