钛种植体基台与种植体上部结构合金的耐腐蚀性能

Corrosion resistance of titanium implant abutments and implant suprastructure dental alloys

背景:国内有学者运用动电位极化技术测定常用牙科金属自腐蚀电位值来评价低贵金属的腐蚀性能,发现合金的贵金属含量是影响其耐腐蚀性能的主要原因。目的:评价TA2型商业纯钛、金合金、钴铬合金、钛合金及镍铬合金的体外耐腐蚀性能。方法:将TA2型商业纯钛、金合金、钴铬合金、钛合金及镍铬合金分别浸入人工唾液中,运用动电位极化技术测量5种材料在人工唾液中的自腐蚀电位和自腐蚀电流密度。结果与结论:5种合金的自腐蚀电位值由大到小排列顺序为金合金、商业纯钛、钛合金、钴铬合金、镍铬合金;金合金与纯钛电位较正,不易发生腐蚀;钛合金和钴铬合金居中,由于可以形成稳定氧化膜,具有较强的抗孔蚀和缝隙腐蚀能力;镍铬合金电位较负,则较容易发生溶解。5种合金的自腐蚀电流密度值排列顺序为金合金<商业纯钛<钛合金<钴铬合金<镍铬合金;金合金与纯钛电流密度值较小,达10-8,这表明金合金和纯钛的腐蚀速度较小,镍铬合金的腐蚀速度最大。结果说明金合金、纯钛是耐腐蚀性较好的材料,镍铬合金的腐蚀速度最大,应尽量避免用镍铬合金作为种植体上部结构。

BACKGROUND：Domestic scholars use the potentiodynamic polarization technique to determine the corrosion potential of the dental aloys, which is used to evaluate the corrosion performance of the lownoble metal. They have discovered that the main reason affecting corrosion resistance is the content of noble metal. OBJECTIVE：To evaluate the corrosion resistance of Ti, Au aloy, Co-Cr aloy, Ti aloy, and Ni-Cr aloy. METHODS： Five aloys were immersed in synthetic saliva solution. The corrosion potential and corrosion current density of the aloys were determined with potentiadynamic polarization technique. RESULTS AND CONCLUSION：The galvanic series of five kinds of aloys were ranged as folows： Au aloy 〉 pure Ti 〉 Ti aloy 〉 Co-Cr aloy 〉 Ni-Cr aloy. Au aloy and pure Ti had more positive potential that were not easy to produce corrosion; Ti aloy and Co-Cr aloy could form stable oxidation film with a strong ability of anti-pitting and crevice corrosion; Ni-Cr aloy potential was more negative and easy to be dissolved. The corrosion current density of five kinds of aloys was ranged as folows： Au aloy 〈 pure Ti 〈 Ti aloy 〈 Co-Cr aloy 〈 Ni-Cr aloy. Au aloy and pure Ti had lowest current density which was 10-8, indicating that the corrosion rate of Au aloy and pure Ti was lower; in contrast, Ni-Cr aloy possessed the maximum corrosion rate. These findings indicate that Au aloy and pure Ti exhibit a very high corrosion resistance. The corrosion rate of Ni-Cr aloy is the highest; therefore, Ni-Cr aloy is the least acceptable material for implant suprastucture.