Global Biocompatibility and Science & Technology Organization, Abbott, St. Paul, Minnesota, USA.
J Biomed Mater Res B Appl Biomater. 2024 Jun;112(6):e35431. doi: 10.1002/jbm.b.35431.
Cobalt-Chromium (CoCr) alloys are currently used for various cardiovascular, orthopedic, fracture fixation, and dental implants. A variety of processes such as casting, forging, wrought processing, hot isostatic pressing, metal injection molding, milling, selective laser melting, and electron beam melting are used in the manufacture of CoCr alloy implants. The microstructure and precipitates (carbides, nitrides, carbonitrides, and intermetallic compounds) formed within the alloy are primarily determined by the type of manufacturing process employed. Although the effects of microstructure and precipitates on the physical and mechanical properties of CoCr alloys are well reviewed and documented in the literature, the effects on corrosion resistance and biocompatibility are not comprehensively reviewed. This article reviews the various processes used to manufacture CoCr alloy implants and discusses the effects of manufacturing processes on corrosion resistance and biocompatibility. This review concludes that the microstructure and precipitates formed in the alloy are unique to the manufacturing process employed and have a significant impact on the corrosion resistance and biocompatibility of CoCr alloys. Additionally, a historical and scientific overview of corrosion and biocompatibility for metallic implants is included in this review. Specifically, the failure of CoCr alloys when used in metal-on-metal bearing surfaces of total hip replacements is highlighted. It is recommended that the type of implant/application (orthopedic, dental, cardiovascular, etc.) should be the first and foremost factor to be considered when selecting biomaterials for medical device development.
钴铬（CoCr）合金目前用于各种心血管、骨科、骨折固定和牙科植入物。制造 CoCr 合金植入物采用了多种工艺，如铸造、锻造、塑性加工、热等静压、金属注射成型、铣削、选择性激光熔化和电子束熔化。合金内部形成的微观结构和析出物（碳化物、氮化物、碳氮化物和金属间化合物）主要取决于所采用的制造工艺类型。虽然文献中对微观结构和析出物对 CoCr 合金物理和机械性能的影响进行了很好的综述和记录，但对其耐腐蚀性和生物相容性的影响尚未进行全面综述。本文综述了用于制造 CoCr 合金植入物的各种工艺，并讨论了制造工艺对耐腐蚀性和生物相容性的影响。本文的结论是，合金中形成的微观结构和析出物是特定于所采用的制造工艺的，对 CoCr 合金的耐腐蚀性和生物相容性有重大影响。此外，本文还包括对金属植入物腐蚀和生物相容性的历史和科学综述。具体来说，强调了 CoCr 合金在全髋关节置换的金属对金属轴承表面使用时的失效。建议在选择用于医疗器械开发的生物材料时，应首先考虑植入物/应用类型（骨科、牙科、心血管等）。
