Center for Research Facilities, Yeungnam University, Gyeongsan 38541, Republic of Korea.
Department of Dental Biomaterials, School of Dentistry and Institute for Biomaterials Research & Development, Kyungpook National University, Daegu 41940, Republic of Korea.
J Nanosci Nanotechnol. 2021 Jul 1;21(7):3950-3954. doi: 10.1166/jnn.2021.19170.
In the context of biology and medicine, nanotechnology encompasses the materials, devices, and systems whose structure and function are relevant for small length scales, from nanometers through microns. The purpose of this study was to compare the microstructures and resultant biocompatibility of three commercially available soft milled cobalt-chromium (Co-Cr) alloys (Ceramill Sintron, CS; Sintermetall, SML; and Soft Metal, SM). Disc-shaped specimens were prepared by milling the soft blanks and subsequent post-sintering. The crystal and microstructures of the three different alloys were studied using optical microscopy, X-ray diffractometry (XRD), energy dispersive X-ray spectroscopy, and electron backscatter diffraction. The amounts of Co, Cr, and molybdenum (Mo) ions released from the alloys were evaluated using inductively coupled plasma-mass spectroscopy. The effect of ion release on the viability of L929 mouse fibroblasts was evaluated by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The SML alloy showed a finer grain size (approx. 5 and a larger pore size (approx. 5 than the CS and SM alloys, and its XRD pattern exhibited a slightly higher ε phase peak intensity than that of the phase. In the CS and SML alloys, the average crystallite sizes of the nano-sized CrC carbide were 21.6 and 19.3 nm, respectively. The SML alloy showed higher concentrations of Cr and Mo in the grain boundaries than the other two alloys. The SML alloy showed significantly higher Co and Mo ion releases (p < 0.001) and significantly lower cell viability (p < 0.05) than the CS and SM alloys. The combined results of this study suggest that the three soft milled Co-Cr alloys had different crystal and microstructures and, as a result, different levels of biocompatibility.
在生物学和医学领域，纳米技术涵盖了材料、器件和系统，其结构和功能与小尺寸有关，从纳米到微米。本研究的目的是比较三种市售软铣钴铬（Co-Cr）合金（Ceramill Sintron，CS；Sintermetall，SML；和 Soft Metal，SM）的微观结构和生物相容性。通过铣削软坯料和随后的后烧结来制备圆盘形试件。使用光学显微镜、X 射线衍射（XRD）、能谱和电子背散射衍射研究了三种不同合金的晶体和微观结构。使用电感耦合等离子体质谱法评估了合金释放的 Co、Cr 和钼（Mo）离子的量。通过 3-（4,5-二甲基噻唑-2-基）-2,5-二苯基四氮唑溴化物测定法评估了离子释放对 L929 小鼠成纤维细胞活力的影响。SML 合金的晶粒尺寸（约为 5 µm）和孔径（约为 5 µm）比 CS 和 SM 合金大，其 XRD 图谱显示 ε 相峰强度略高于 相。在 CS 和 SML 合金中，纳米级 CrC 碳化物的平均晶粒尺寸分别为 21.6nm 和 19.3nm。SML 合金的晶界处 Cr 和 Mo 的浓度明显高于其他两种合金。SML 合金表现出明显更高的 Co 和 Mo 离子释放（p < 0.001）和明显更低的细胞活力（p < 0.05），比 CS 和 SM 合金。本研究的综合结果表明，三种软铣 Co-Cr 合金具有不同的晶体和微观结构，因此具有不同的生物相容性水平。
