de Mele M F, Salvarezza R C, Videla H A
Biomaterials. 1986 Jul;7(4):297-300. doi: 10.1016/0142-9612(86)90054-2.
In previous studies it was observed that endodontic silver cones placed in fine canals became dislodged as a result of corrosion. To investigate the corrosion of high purity silver, potentiostatic and potentiodynamic electrochemical techniques were used. Triangular potential sweeps made in physiological solutions and human plasma showed similar potential-current relationships. However, in human plasma, peak currents were lower and peak potentials were more anodic than those observed in the physiological solutions. The electron microprobe analysis and the EDAX of the film formed in the biological fluids revealed the presence of silver and chloride and a certain amount of carbon. The addition of small quantities of Na2S to the physiological solutions favoured metal dissolution and promoted the formation of a mixed film of AgCL and Ag2S. According to these results chloride and sulphide anions seem to be particularly aggressive towards the metal surface in implanted silver cones. Precautions to avoid direct contact of the cones with saliva and tissue fluids must be taken. Fractures and discontinuities present in the cement considerably increase the corrosion risks.
在以往的研究中观察到，置于细根管内的牙髓银尖会因腐蚀而移位。为研究高纯度银的腐蚀情况，采用了恒电位和动电位电化学技术。在生理溶液和人体血浆中进行的三角电位扫描显示出相似的电位-电流关系。然而，在人体血浆中，峰值电流较低，且峰值电位比在生理溶液中观察到的更偏向阳极。对在生物流体中形成的膜进行的电子微探针分析和能谱分析表明，存在银、氯以及一定量的碳。向生理溶液中添加少量的Na2S有利于金属溶解，并促进形成AgCL和Ag2S的混合膜。根据这些结果，氯和硫阴离子似乎对植入的银尖中的金属表面具有特别强的侵蚀性。必须采取预防措施以避免银尖与唾液和组织液直接接触。粘固剂中存在的裂缝和不连续会大大增加腐蚀风险。
