Marek M, Okabe T, Butts M B, Fairhurst C W
J Biomed Mater Res. 1983 Nov;17(6):921-9. doi: 10.1002/jbm.820170604.
Previous studies have shown preferential corrosion of the eta'(Cu-Sn) phase in high-copper dental amalgam both in vitro and in vivo, while samples of pure eta' have shown high corrosion resistance. To clarify this contradiction, samples of pure eta' crystals mixed with other phases were prepared and tested. Evaluation of the corrosion resistance was based on the results of coulometry at constant potential and potentiodynamic polarization. The corrosion susceptibility of eta' in the matrix of gamma 1(Ag-Hg) was considerably higher than the susceptibility of isolated eta'. The susceptibility of pure eta' also could be increased by plating it will small amounts of Hg. It was concluded that in dental amalgam, the presence of mercury in the phases surrounding eta' reduces its resistance to corrosion. Although eta' is more resistant to corrosion than gamma 2(Sn-Hg) which appears in low-copper amalgams, it is the least corrosion resistant major phase in high-copper amalgams and can suffer deterioration.
先前的研究表明，在体外和体内环境下，高铜牙科汞齐中的η'（Cu-Sn）相均会发生优先腐蚀，而纯η'样品则显示出高耐腐蚀性。为了澄清这一矛盾，制备并测试了与其他相混合的纯η'晶体样品。耐腐蚀性评估基于恒电位库仑法和动电位极化的结果。η'在γ1（Ag-Hg）基体中的腐蚀敏感性明显高于孤立的η'。通过在纯η'上镀少量汞，其敏感性也会增加。得出的结论是，在牙科汞齐中，η'周围相中汞的存在会降低其耐腐蚀性。尽管η'比低铜汞齐中出现的γ2（Sn-Hg）更耐腐蚀，但它是高铜汞齐中耐腐蚀能力最差的主要相，可能会发生劣化。
