Luthy H, Marinello C P, Reclaru L, Scharer P
Department of Fixed and Removable Prosthodontics and Dental Materials, University of Zurich, School of Dentistry, Switzerland.
J Prosthet Dent. 1996 May;75(5):515-24. doi: 10.1016/s0022-3913(96)90456-4.
Cobalt-based alloys (Co-Cr-Mo) are usually used in dentistry as frameworks for removable partial dentures. In their basic form these structures function successfully. However, modifications or repairs of the frameworks may reduce their resistance to corrosion and, as a consequence, may provoke biologic reactions in the soft tissues. These reactions may be the result of different types of alloys that contact each other and, in the presence of saliva (based on potential differences), produce a galvanic cell. In this study, a clinical situation after repair of a removable partial denture was examined. The metallographic study of the prosthesis revealed a brazed zone where a gold braze was joining the Co-Cr-Mo framework with a Co-Cr-Ni type alloy (without Mo). The latter revealed signs of corrosion. Various electrochemical parameters (Ecorr, Ecouple, icorr, icouple) of these alloys were analyzed in the laboratory. The Co-Cr-Ni alloy had the lowest nobility and underwent galvanic corrosion in a galvanic couple with gold braze.
钴基合金（Co-Cr-Mo）通常在牙科中用作可摘局部义齿的框架。这些结构在其基本形式下能成功发挥功能。然而，框架的修改或修复可能会降低其耐腐蚀性，结果可能会引发软组织中的生物反应。这些反应可能是由于不同类型的合金相互接触，并在唾液存在的情况下（基于电位差）产生原电池所致。在本研究中，对一副可摘局部义齿修复后的临床情况进行了检查。对该假体的金相研究发现了一个钎焊区，其中金钎料将Co-Cr-Mo框架与Co-Cr-Ni型合金（不含Mo）连接在一起。后者显示出腐蚀迹象。在实验室中分析了这些合金的各种电化学参数（Ecorr、Ecouple、icorr、icouple）。Co-Cr-Ni合金的贵金属性最低，在与金钎料形成的原电池中发生了电偶腐蚀。
