缩醛树脂卡环形变的体外实验研究

摘要

Objective To observe the tendency of deformation of acetal resin clasps during the repeated cycles of placement and removal. Methods The Co-Cr clasps and the acetal resin-Co-Cr clasps used in clinic were tested by instron electronic universal testing machine and electronic digital display. To measure the change of distance between the retention clasps and resistance clasps, and the change of thickness of the acetal resin-Co-Cr clasps on premolar of different material (heat curing resin teeth, extracted teeth, cobalt-chromium alloy teeth) before and after 2 880 dislocation cycles. Results After 2 880 dislocation cycles, there was significant increase in the distance between the tips of Co-Cr clasps (P<0. 01 ) , but not for the acetal resin clasps ( P > 0. 05 ). On the tooth of different material, the thickness of acetal resin clasps all showed tendency of attenuation, the thickness of clasps on heat curing resin teeth was significantly higher than the other two types (P<0.05). Conclusions The deformation of acetal resin clasp was lower than casting clasp. There were significant differences among the deformation of acetal resin clasp on various material teeth.%目的 观察缩醛树脂(POM)卡环在反复脱位循环过程中形变的变化趋势.方法 使用 Instron电子万能材料试验机和电子数显卡测试钻铬合金卡环和临床常用 POM—钻铬合金联合三臂卡环在不同材质(热凝塑料牙、离体牙、钻铬合金牙)前磨牙上2 880次脱位循环前后,卡环固位臂卡环尖和抗力臂卡环尖之 间的距离变化值,以及POM—钻铬合金联合三臂卡环固位臂厚度的变化值.结果 2 880次循环周期后,钻铬合金卡环的固位臂卡环尖和抗力臂卡环尖之间的距离增加(p＜0.O1),而POM卡环的固位臂卡环尖和抗力臂卡环尖之间的距离无明显变化(p＞0.05);在不同材质基牙上,POM卡环臂厚度均呈衰减趋势,塑料牙组卡环臂的厚度测定值分别高于离体牙组和钻铬合金牙组(P均＜0.05).结论 POM卡环形变低于铸造合金卡环；不同基牙材质对POM卡环形变量的影响存在差异.