Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA, CCT La Plata-CONICET), Facultad de Ciencias Exactas, Departamento de Química, Universidad Nacional de La Plata, Casilla de Correo 16, Sucursal 4, 1900 La Plata, Argentina.
J Biomed Mater Res A. 2013 Jul;101(7):2129-40. doi: 10.1002/jbm.a.34503. Epub 2013 Apr 18.
The use of copper-based alloys for fixed dental crowns and bridges is increasingly widespread in several countries. The aim of this work is to study the dissolution of a zinc-aluminum-bronze and the cytotoxic effects of the ions released on UMR-106 osteoblastic cell line. Two sources of ions were used: (1) ions released by the metal alloy immersed in the cell culture and (2) salts of the metal ions. Conventional electrochemical techniques, atomic absorption spectroscopy [to obtain the average concentration of ions (AC) in solution], and energy dispersive X-ray (EDX) spectroscopy analysis were used to study the corrosion process. Corrosion tests revealed a strong influence of the composition of the electrolyte medium and the immersion time on the electrochemical response. The cytotoxicity was evaluated with (a) individual ions, (b) combinations of two ions, and (c) the mixture of all the ions released by a metal disc of the alloy. Importantly, synergistic cytotoxic effects were found when Al-Zn ion combinations were used at concentration levels lower than the cytotoxic threshold values of the individual ions. Cytotoxic effects in cells in the vicinity of the metal disc were also found. These results were interpreted considering synergistic effects and a diffusion controlled mechanism that yields to concentration levels, in the metal surroundings, several times higher than the measured AC value.
在一些国家，铜基合金越来越多地被用于固定牙冠和牙桥。本研究旨在研究锌铝合金的溶解以及释放的离子对 UMR-106 成骨细胞系的细胞毒性作用。使用了两种来源的离子：（1）浸在细胞培养液中的金属合金释放的离子，（2）金属离子的盐。采用常规电化学技术、原子吸收光谱法[获得溶液中离子的平均浓度（AC）]和能量色散 X 射线（EDX）光谱分析来研究腐蚀过程。腐蚀试验表明，电解质介质的组成和浸泡时间对电化学响应有很强的影响。通过（a）单独的离子、（b）两种离子的组合以及（c）合金金属盘释放的所有离子的混合物来评估细胞毒性。重要的是，当 Al-Zn 离子组合在低于单个离子细胞毒性阈值的浓度水平下使用时，发现了协同细胞毒性作用。在金属盘附近的细胞中也发现了细胞毒性作用。这些结果考虑到协同作用和扩散控制机制进行了解释，该机制导致金属周围的浓度水平比测量的 AC 值高几倍。
