3种印模材料制取活动义齿模型的三维精度比较

目的：评价硅橡胶类、琼脂类和藻酸盐类(水粉调料型)等3种印模材料的取模精度。方法：分别用3种印模材料制取10个同一实验主模具的人造石模型，用电子游标卡尺测量主模具和石膏模型上各标志点的距离，精度为0.01mm，所得数据进行统计分析。结果：硅橡胶类印模材料制取的石膏模型线性变化率最小且比主模型稍大，与琼脂类和藻酸盐类印模材料制取的印模在三维尺寸变化率方面无显著差异。结论：硅橡胶类印模材料的取模精度最高，琼脂类印模材料因取模精度高，操作比较简单，且价格易于接受等优点，值得在临床推广。

3D Accuracy of Three Types of Impression Materials for Removable Partial Denture

Objective: To investigate the 3D accuracy of three impression materials for removable partial denture. Methods: Three kinds of impression materials,such as silicone(IP),hydrocolloid(ZJ)and alginate impression(BS),were used in this experiment. Ten plaster replication models for each impression materials were made on the same master model repectively,vertical and horizontal dimensions between landmarks on the masters and plaster casts were measured with an electronic caliper .One-way ANOVA was used to compare the measurements among the materials. Results: The difference between the masters and casts in all measured dimensions on IP produced models was the smallest but compared with other two impression materials, the difference was not significant (P>0.05). Conclusion: The silicone material is the accurarest and hytrocolloid is relatively accurate.