Ravnholt G, Jensen J
Department of Prosthetic Dentistry and Stomatognathic Physiology, Royal Dental College, Aarhus, Denmark.
Scand J Dent Res. 1991 Apr;99(2):181-6. doi: 10.1111/j.1600-0722.1991.tb01882.x.
The corrosion of two materials for implant supraconstructions, a carbon fiber/PMMA composite and a silver-palladium alloy, was investigated in vitro, the materials being galvanically coupled to a titanium implant. Corrosion current and pH of the electrolyte were monitored, and corrosion products were identified by powder X-ray diffraction. The carbon composite and the silver-palladium per se did not corrode, whereas a silver-palladium specimen brazed with the recommended brazing alloy corroded unmistakably, yielding copper-containing corrosion products. The action of local corrosion cells around the brazed joint is considered, and it is concluded that the two materials seem well suited for implant supraconstructions, provided that brazing the silver-palladium can be avoided. Considering the clinical relevance of the experimental model used, it is concluded that the model is likely to predict a lower corrosion susceptibility than the one found in vivo.
研究了两种用于种植体上部结构的材料，即碳纤维/聚甲基丙烯酸甲酯复合材料和银钯合金在体外的腐蚀情况，这些材料与钛种植体形成电偶连接。监测了电解质的腐蚀电流和pH值，并通过粉末X射线衍射鉴定了腐蚀产物。碳复合材料和银钯本身不会腐蚀，而用推荐的钎焊合金钎焊的银钯试样明显腐蚀，产生含铜的腐蚀产物。考虑了钎焊接头周围局部腐蚀电池的作用，得出的结论是，只要能避免银钯的钎焊，这两种材料似乎非常适合用于种植体上部结构。考虑到所使用的实验模型的临床相关性，得出的结论是，该模型预测的腐蚀敏感性可能低于体内发现的情况。
