不同pH值与氟离子浓度对口腔常用金属修复材料电化学腐蚀的影响

目的 研究不同pH值与不同浓度氟离子(F-)对HBIC种植体和常用的四种冠修复金属材料在人工唾液中电化学腐蚀的影响.方法 将5种口腔常用金属,金合金(Au)、镍铬合金(NiCr)、钴铬合金(CoCr)、铸造纯钛(Ti)、HBIC种植钛材(H-Ti)分别置于不同pH值与含和不含F-的人工唾液中,采用动电位极化曲线法测得其自腐蚀电位和自腐蚀电流密度,分析材料的耐腐蚀性.结果 金合金、钴铬合金、镍铬合金的腐蚀电流密度随着H+的浓度增加而变大,差异有统计学意义(P<0.05),铸造纯钛及种植钛材在酸性含氟人工唾液中的腐蚀电流密度和自腐蚀电位变化明显,差异有统计学意义(P<0.05),F-对金合金的耐腐蚀性影响不明显.结论 pH的改变以及含氟环境会加剧种植体及其常用上部冠修复材料的电化学腐蚀性,金合金与纯钛的耐腐蚀性能较强.

Effect of different pH value and fluoride on corrosion of cast metal

Objective To investigate the effect of the different pH and fluoride on five kinds of commonly used dental metals.Methods Specimens of gold alloy (Au), cobalt chromium alloy (CoCr), nickel chromium alloy(NiCr), pure titanium (Ti) and dental implant (H-Ti) were prepared and placed in artificial saliva.The corrosion potential (Ecorr) and the corrosion current density (Icorr) of the materials were tested by electrochemical measurement system.Results The corrosion current density of Ni-Cr alloys, Co-Cr alloy and Au-Pt alloy increased significantly in artificial saliva with pH=4(P<0.05).The corrosion current density of pure titanium and dental implant(H-Ti) changed significantly in artificial saliva with pH=4 and 0.1% F-(P<0.05).But the corrosion of the gold alloy did not change in the artificial saliva.Conclusion The change of pH and the fluoride aggravated the electrochemical corrosion of the dental implant and the upper crown restoration materials.The gold alloy and pure titanium had higher corrosion resistance.