钛种植体与冠修复金属电偶腐蚀电流的研究

A study of the galvanic corrosion current between Ti implant and crown alloys

目的通过对HBIC型钛种植体与口腔科常用修复烤瓷合金在中性和酸性人工唾液中的电偶腐蚀的综合评价,筛选更适合种植体上部结构的冠修复材料。方法选择HBIC型钛种植体(T-H)以及镍铬合金(Ni)、钴铬合金(Co)、金铂合金(Au)、铸造纯钛(Ti),每种金属制成直径4mm、高10mm的圆柱体电极各40个。采用电化学方法,在自行配制的p H=6.8、pH=5.6两种人工唾液中检测4种合金分别与T-H组成的电偶对的电偶电流密度(Id),并绘制出各自的电流时间曲线。结果在中性人工唾液中四种电流密度依次为I_(dNi)>I_(dCo)>I_(dTi)>I_(dAu),其中Ni组与Au组、Ti组间有统计学差异(P<0.05),Co组与Ni组、Ti组、Au组,Ti组与Au组间无统计学差异(P>0.05)。在酸性人工唾液中四种电流密度依次为_(dNi)>I_(dCo)>I_(dAu)>I_(dTi),其中Ni组显著大于Ti组、Co组、Au组,有统计学差异(P<0.05),Ti组、Co组、Au组三组间无统计学差异(P>0.05)。扫描电镜观察,酸性环境中镍铬合金发生少量坑状腐蚀形貌,其余合金与中性环境相比无明显变化。结论两种唾液中镍铬合金组电偶电流较大。酸性环境能增大电偶腐蚀,对镍铬合金影响较大,镍铬合金不适宜作为钛种植体上部冠修复材料。

Objective To evaluate the galvanic corrosion between titanium implant and prosthetic restoration alloys in neutral and acidic artificial saliva. Methods HBIC titanium implant（ T-H）,Ni,Co,Au and Ti were made into metal electrodes respectively. Each electrode included 4 specimens. The galvanic current＇s density of galvanic couple composed by four alloys with T-H was recorded using the electrochemical method in two different kinds of artificial saliva（ pH = 6. 8,pH = 5. 6） respectively. The current-time curves were drawn. Results In the neutral artificial saliva,the highest current density was Id Ni,while the lowest current density was IdAu. Significant differences were found between the Ni group and Au group,as well as between the Ni group and Ti group（ P〈 0. 05）. In the acidic artificial saliva,the highest current density was IdNi,while the lowest current density was IdTi. Significant differences were found between the Ni group and the other three groups（ P 〈0. 05）. Conclusion The galvanic current of Ni-Cr alloy was higher in the two kinds of saliva. The acidic environment could increase the galvanic corrosion,which had a greater impact on the Ni-Cr alloy. Ni-Cr alloy is not suitable for a Ti implant prosthetic restoration.