【摘要】 目的观察两种材料的T型卡环作用于烤瓷冠时,其固位力大小的变化趋势以及烤瓷冠相应表面的磨损情况。方法制作烤瓷冠标准试件及钴铬合金和纯钛的T型卡环,采用BOSE Electroforce测试仪进行15000次反复就位、脱位实验,记录分析卡环脱位力的峰值及其衰减曲线。用扫描电子显微镜观察烤瓷冠表面的磨损情况。结果两组卡环固位力衰减规律基本符合对数曲线,拟合曲线方程钴铬合金卡环为y=-5.043lnx+51.494,纯钛卡环为y=-2.622lnx+29.519。电镜可见钴铬合金卡环组烤瓷冠表面明显断层结构及较大面积的材料缺失;纯钛卡环组烤瓷冠材料剥脱较少,断层较薄。结论钴铬合金和纯钛的T型卡环固位力变化符合对数衰减;纯钛卡环的固位力维持优于钴铬合金卡环。对烤瓷冠表面的磨损程度,纯钛卡环明显低于钴铬合金卡环。更多还原

【Abstract】 Objective To investigate the retention force attenuation and the surface abrasion between T bar clasp and the porcelain crown.Methods Two kinds of porcelain crowns and corresponding T bar clasps made of Cr-Co alloy and pure titanium were constructed.A total of 15000 times of placement and removal were carried out on BOSE Electroforce testing machine.The surface abrasion of the crowns was observed by scanning electron microscope.Results The logarithm attenuation law was observed in both groups.The equations were y=-5.043lnx+51.494 in the group of Cr-Co alloy clasp and y=-2.622lnx+29.519 in the group of pure titanium clasp.Scanning electron microscopy showed obvious material denudation and fault structures in the group of Cr-Co alloy clasp.There was less material loss in pure titanium clasp group than in Cr-Co alloy clasp group.Conclusion The logarithm attenuation law is observed in the T bar clasps made of Cr-Co alloy and pure titanium.The ability of maintaining the retention force of the pure titanium bar clasp is superior to that of the Cr-Co alloy bar clasp.The abrasion of the porcelain crown for the pure titanium bar clasp is less slight compared with that for the Cr-Co alloy bar clasp.更多还原