2种金属衔铁抗腐蚀性能比较

目的比较镍铬合金衔铁和金合金衔铁在人工唾液中的抗腐蚀性。方法将成品衔铁(设为对照组)分别与镍铬合金和金合金铸接后,形成镍铬合金衔铁(设为镍铬合金组)和金合金衔铁(设为金合金组)。分别浸泡于人工唾液中,测得动电位极化曲线。同步选择下颌仅存留一个基牙(尖牙或双尖牙)的25例患者(戴镍铬合金组附着体义齿的13例、戴金合金组附着体义齿的12例),分别测定其咀嚼效率。结果镍铬合金组衔铁在电位400 mV以下时,电流密度增加较慢,腐蚀较慢;在400 mV以上,电流密度增加较快,腐蚀较快;其腐蚀速率为(0.0456±0.0003)mm/a。金合金组衔铁在400 mV以下时,电流密度增加较快,腐蚀较快;在400 mV以上,电流密度增加较慢,腐蚀较慢;其腐蚀速率为(0.0291±0.0016)mm/a。镍铬合金组附着体,在第1周、第1个月、第2个月、第3个月咀嚼效率吸光度均值分别为0.661±0.137、0.845±0.017、0.786±0.026、0.801±0.074。金合金组附着体,在第1周、第1个月、第2个月、第3个月咀嚼效率吸光度均值分别为0.651±0.130、0.861±0.031、0.811±0.035、0.862±0.072。金合金组的咀嚼效率稍大于镍铬合金组,但2组比较差异无统计学意义(P>0.05)。结论在人工唾液中,镍铬合金组和金合金组均会被腐蚀,但仍能满足临床要求,均能很好地恢复患者的咀嚼功能。

Comparison of the anti-corrosive ability of the two kinds of metal armatures

Objective To compare the anti-corrosive ability of the Ni-Cr alloy and the gold alloy armature in the artifieial saliva. Methods The product armature respectively with the Ni-Cr alloy and the gold alloy after that casted, to forming a chain of nickel, chromium alloy and gold alloys. Immerse the two kinds of armature into the artificial saliva then make the potentiodynamic curve. Consecutive select 25 patients with 1 normal tooth left in the mandible （13 with the Ni-Cr alloy dentures and 12 with the gold alloy armature dentures） ,and measure the chewing effieiency of patients of the two groups respectively. Results When below 400 mV, there was a low increase rate of polarization electric density and a small corrosive rate of the Ni-Cr alloy, and when above 400 mV, the results were opposite and the self-repairing ability was awful, and its conosion velocity was （0.0456 ± 0.0003 ）mm/a. At the same conditions ,the results of the gold alloy were very different from the Ni-Cr alloy and the former had strong self-repairing a- bility with a eonosion velocity was （0. 0291 ±0.0016 ）mm/a. The average absorbance rates （chewing efficiency） of the patients with the Ni-Cr alloy dentures measured in 1st week, 1st month,2nd month,3rd month were 0. 661 ±0. 137,0. 845 ±0.017,0. 786 ±0. 026,0. 801 ±0. 074, respectively, while those of the patients with the Gold alloy dentures were 0.651 ±0.130 ,0. 861 ±0.031,0.811 ±0. 035 and 0.862 ±0.072, respectively. The chewing efficiency of the gold alloy dentures was larger than that of the Ni-Cr alloy, although there was no statistical significant （ P 〉 0.05）. Conclusion Although there were corrosions observed in the artificial saliva of both the Ni-Cr alloy armature and the gold alloy armature, they would still meet the clinical needs. The patients with dentures of the two kinds of metal alloy armatures could all rehabilitate with good chewing ability.