用三维空间标记法测量口腔印模材料的体积变化率

摘要

目的：使用三维标记法测定4种常用印模材体积变化率．方法：每种印模材在金属母模上制取3份试件后使用形状轮廓扫描仪扫描及建模，通过专用软件在试件模型上划出标记空间，并测量不同存放时间标记空间内体积，计算试件的体积变化率．结果：CAVEX 藻酸盐在15、180 min 时体积变化率分别为1.432％、8.343％；Zher-mark 藻酸盐在15、180 min 时体积变化率分别为1.772％、7.580％；ExpressXT Penta H 硅橡胶在1、36 h 体积变化率分别为0.047％、0.364％；Impregum Penta 聚醚橡胶在1、36 h 体积变化率分别为0.012％、0.336％．2种藻酸盐体积变化率间无统计学差异（P ＞0.05），2种人工合成橡胶体积变化率间的差值无统计学意义（P ＞0.05），藻酸盐与人工合成橡胶体积变化率间差值具有统计学意义（P ＜0.01）．结论：藻酸盐类印模材体积变化率大于人工合成橡胶类印模材；三维空间标记法适用于印模试件形变的直接测量．%Aim:To investigate the dimensional changes of 4 impression materials.Methods:An alu-minum alloy model and a custom tray were fabricated.Impression samples with 4 impression materials (including 2 alginate materials and 2 elastomers)were made from a reference model.All samples were scanned and evaluated for volumetric changes by using a 3D microscope measurement with space labe-ling.Results:The volumetric change rate of CAVEX alginate samples was 1.432% in 15mins,and was 8.343% in 180 mins;while the volumetric change rate of Zhermark alginate samples was 1.772% in 15mins,and was 7.580% in 180mins;however,the volumetric change rate of ExpressXT Penta H sili-cone samples was 0.047% in 1hour,and was 0.364% in 36 hours;while that of Impregum Penta poly-ether samples was 0.012% in 1hour,and was 0.336% in 36 hours.There was no statistical difference (P >0.05)in volumetric change rates between CAVEX and Zhermark alginate samples,and also no sta-tistical difference(P >0.05)in volumetric change rates between ExpressXT Penta H silicone and Imp-regum Penta polyether samples either.Statistical differences of volumetric change rates were found be-tween alginate materials and elastomers.Conclusion:Dimensional stability of elastomeric materials was better than that of alginate materials.The space-labeling method is a feasible and direct measurement for dimensional staability of impression materials.