Hattori Masayuki, Tokizaki Teruhiko, Matsumoto Michihiko, Oda Yutaka
Department of Dental Materials Science, Tokyo Dental College, Mihama-ku, Chiba, Japan.
Bull Tokyo Dent Coll. 2010;51(1):7-13. doi: 10.2209/tdcpublication.51.7.
In this study, the corrosion resistance of Ag-Au-Cu-Pd system alloys consisting of 5 or 10 mass% indium was evaluated. Levels of element release and tarnish were determined and electrochemical measurements performed. Results were compared with those for commercial silver-palladium-gold alloy. In terms of electrochemical behavior, the transpassive potential of these experimental alloys was 168-248mV. Experimental alloys with 25 mass% Au showed similar corrosion resistance to control gold-silver-palladium alloy. Amount of released elements was 14-130microg/cm(2) at 7 days, which is in the allowable range for dental alloys. Addition of indium to Ag-Au-Cu-10mass%Pd system alloys was effective in increasing resistance to tarnish and alloys containing 10 mass% of indium showed a minimal decrease in L(*) values after immersion. These findings indicate that 25Au-37.5Ag-15Cu-10Pd-2Zn-10In-0.5Ir alloy is applicable in dental practice.
在本研究中，对含5%或10%质量分数铟的Ag-Au-Cu-Pd系合金的耐腐蚀性进行了评估。测定了元素释放量和失泽情况，并进行了电化学测量。将结果与商用银钯金合金的结果进行了比较。就电化学行为而言，这些实验合金的过钝化电位为168 - 248mV。含25%质量分数金的实验合金表现出与对照金银钯合金相似的耐腐蚀性。7天时元素释放量为14 - 130μg/cm²，处于牙科合金的允许范围内。向Ag-Au-Cu-10%质量分数Pd系合金中添加铟可有效提高抗失泽能力，含10%质量分数铟的合金浸泡后L*值的下降最小。这些发现表明，25Au-37.5Ag-15Cu-10Pd-2Zn-10In-0.5Ir合金适用于牙科实践。
