牙科金属材料的组成对细胞毒性影响的研究

STUDY ON CYTOTOXIC EFFECT OF COMPOSITE OF DENTAL METAL MATERIALS

选择９种中日常用的牙科金属和合金材料，其基本组成是Ｎｉ－Ｃｒ，Ｃｏ－Ｃｒ－Ｍｏ，Ａｇ－Ｐｄ－Ａｕ－Ｃｕ，Ａｇ－Ｚｎ，Ｎｉ－Ｔｉ，Ｎｉ－Ｃｒ－Ｃｏ和Ｃｕ基，用Ｌ－９２９小鼠成纤维细胞，经细胞－金属表面直接接触４８ｈ，对去除刺激因素的细胞，用紫外分光光度仪和扫描电镜进行检测，并在原子吸收光谱仪下定量分析材料浸渍液中溶出金属元素的成分，直接研究金属的化学组成、溶解元素对细胞毒性的影响。结果表明：Ｃｕ基合金因合金中存在较大比例的铜元素（７８％），显示较明显的细胞毒性；Ｎｉ－Ｃｒ合金和Ｎｉ－Ｔｉ合金由于可在合金表面分别形成保护性氧化层和高粘接性氧化钛表层，因而均显示良好的生物学性能；部分合金虽然含有毒元素Ｃｕ和Ｚｎ，但因合金中具有化学稳定的贵金属元素存在（如Ｐｄ、Ａｕ、Ａｇ），表现出无明显细胞毒性。因此，作者认为：（１）金属或合金中某些元素的存在与否以及含量多少与细胞毒性之间存在着一定的关系；（２）运用直接接触的体外细胞回复度试验技术来评价材料的细胞毒性是有效和可取的。

Nine kinds of Japanese Chinese commercial dental metal or alloys were selected for study. The main composite are Ni Cr, Co Cr Mo, Ag Pd Au Cu, Ag Zn,Ni Ti, Ni Cr Co and Cu based. L 929 cells were used to contact metal surface directly for 48 hours, then harvesting all cells and transferring into a new medium. After 0 and 4 days, all cells were tested and evaluated with spectrophotometer and SEM. The metal ions dissolved in the old medium were analysed by atomic absorption spectroscopy. The cytotoxic effect of composite of dental metal materials were thus investigated, and results showed: 1) Cu based alloy had some cytotoxicity possibly due to cyto inhibition effect of Cu; 2) the high biocompatibility of Ni Cr alloy and 18 8 stainless steal were probably due to formation of a protective oxide layer of Cr, and that of Ni Ti alloy was due to formation of a highly adherent layer of TiO on Ti samples; 3) Ag Pd Au Cu and Ag Zn alloys had no apparent cytotoxicity because Au, Pd or Ag were elements of high chemical stability. The authors suggested that cytotoxicity of dental metal materials was due to the presence of some metal elements.