差异化扫描临床全冠预备体的数字化印模精度比较

目的 比较临床全冠预备体石膏模型口内扫描仪数字化印模与口外扫描仪数字化印模精度的差异。方法 临床制备全冠患牙20例，牙体预备后取硅橡胶印模并灌注石膏模型，对预备体模型用临床口内扫描仪和技工室口外扫描仪分别扫描，获得两组数字化模型，进行数据转换并保存为STL文件。测量两组印模数据的三维差异，评估不同数字化印模方式之间的精度差异。结果 全冠预备体模型的口内数字化印模和口外数字化印模比较，各观测点间的精度差异没有统计学意义（P>0.05）。结论 全冠预备体印模使用口内扫描仪与口外扫描仪形成的数字化印模具有一致性，提示了影响口内扫描精度的个体差异和总体局限性因素，为进一步提高临床数字化印模精度给出一个基础性参考。

A comparison of digital impression accuracy of clinical crown preparation with differential scanning

Objective To compare the difference of digital impression precision between the intraoral scanner and extraoral scanner in the plaster models of clinical full crown preparation. Methods Twenty full-crown teeth were clinically prepared. After tooth preparation, the silicone rubber impression was taken and the plaster model was poured into the model. The model was scanned respectively with an intraoral scanner and an extraoral scanner in the laboratory. The three-dimensional difference between two sets of impression and the difference of precision between different impression methods was evaluated. Results There was no statistically significant difference in the accuracy between the two observation points (P>0.05). Conclusions The digital impression mold data by the intraoral scanner was consistent with that by the extraoral scanner in the full crown preparation impression. The results suggest that individual differences and overall limitations might affect the accuracy of intraoral scanning, providing a basic reference for further improving the accuracy of clinical digital impression.