pH对银汞合金腐蚀性能的影响

为研究环境ｐＨ值改变对银汞合金腐蚀性能的影响，利用美国３６８－电化学腐蚀测试系统，对４种银汞合金在ｐＨ为６．６５和４．００的人工唾液中的自然腐蚀电位、极化电阻、极化曲线进行测试。结果表明：ｐＨ的改变对不同的合金材料产生的影响不同，４种银汞合金在ｐＨ酸移后的耐腐蚀性从强到弱依次为：高铜银汞合金（昆明产）＞高铜银汞合金（北京产）＞高铜银汞合金（美国产）≥低铜银汞合金（上海产），这与临床观察的结果是一致的。说明金属本身的耐腐蚀性不同，其表面附着膜的变化情况亦不同，故临床上选择耐腐蚀合金材料应考虑到口腔中不断变化的ｐＨ的影响。

The effect of pH on anti corrosion nature of amalgams

Corrosion behavior of alloys are affected not only by themselves but also by environment, such as a change of pH. In this study, the corrosion behavior of four dental amalgams (L, C, DA, GK) in Fusayama saliva with different pH 6.65 and 4.00 are evaluated by electrochemical techniques. It seems that changes in pH may exert different effects on the four amalgams. In the acid environment DA exhibits best anti-corrosion nature and followed by GK, C, and L, which conforms to clinical observations. This may be resulted either from amalgams themselves or from conditions of corrosion products of amalgams' surface. Thus, consideration must be given to the changing oral environment when screening anti-corrosion alloys.