A Study on Clinical Evaluation of Dental Casting Alloys

为了解牙科铸造合金在口腔中的变化，进行了以下实验。用四种牙科铸造合金制作了牙科铸造嵌体，并在几个年轻人的磨牙上临时固定了1个月和3个月。经过1个月或3个月的临时粘接后，用扫描电子显微镜观察各合金表面的变化，并用电子探针分析其化学成分。结果表明：(1)金合金和银-钯-铜-金合金表面变化很小，口腔化学成分变化不大；(2)银-锡-锌合金表面变化明显，尤其是颊、牙龈侧变化明显；(3)虽然70Ni-19Cr合金在体内外均有明显变化，但口腔变化不明显。这些结果的原因现在正在研究中。

The following experiment was performed for the purpose of examining changes of dental casting alloys in human mouths. Class <II> cast inlays were fabricated with four kinds of dental casting alloys and had been temporarily fixed in molars of several young adults for 1 and 3 months. After 1 or 3 months temporary cementation, surface changes of each alloy were observed by SEM and the chemical composition was also analyzed by EPMA. The results are as follows.(1) Gold alloy and Ag-Pd-Cu-Au alloy showed very few changes in surface and there were few changes observed in chemical composition of both alloys in mouths.(2)Ag-Sn-Zn alloy was obviously changed in surface and remarkable changes were seen especially on buccal and gingival sides of proximal surface.(3)Though 70Ni-19Cr alloy showed remarkable changes in vitro and in vivo, few changes were observed in mouths. The cause of these results are now examining.