3种石膏材料构建的全冠数字化模型精度的对比研究

Accuracy of digital models of full crowns constructed by three types of dental gypsum materials：a comparative study

摘要:

目的：研究Cerec Inlab MC XL 系统3种石膏材料构建的全冠数字化模型的精度。方法：制备一标准右上第一磨牙全冠预备体模型，并复制超硬石膏、Esthetic-base、CAM-base石膏扫描代型各8个。每组代型采用InEos扫描仪Rotational旋转扫描方式分别获取数字化模型8个（超硬石膏组采取喷粉后扫描），Inlab 3D（version 3.65）软件测量每个数字化模型相应位点的距离参数并与实物比较。本实验采用SPSS 19.0统计软件对数据进行分析。结果：超硬石膏组的成像质量略优于Esthetic-base组和CAM-base组。Esthetic-base组、CAM-base组与实物组在颊舌（P=0.199）、近远区域（P=0.087）的测量值比较差异无统计学意义，但超硬石膏组与实物组比较有统计学差异（P=0.00，P=0.003）。此外，超硬石膏组在近远区域的偏差值较颊舌区域大，差异有统计学意义（F=7.310，P=0.000）。超硬石膏组、Esthetic-base组、CAM-base组的总体偏移值分别为（0.049±0.036）、（0.016±0.050）、（0.017±0.052） mm。结论：在本实验条件下Esthetic-base、CAM-base石膏构建的数字化模型精度较高，而超硬石膏喷粉构建的数字化模型精度较差，不推荐使用。

Abstract:

Objective：To investigate the accuracy of digital models of full crowns which were constructed by three types of dental gypsum materials in Cerec Inlab MC XL system. Methods：A upper first right molar in the standard model was prepared，and eight scanned models made of superhard gypsum，Esthetic-base gypsum，and CAM-base were duplicated respectively. Eight digital models in each group were digitally imaged by scanning in InEos unit with Rotational method（superhard gypsum was scanned after spraying powder）. The distance parameters of each digital model were measured by inlab 3D software（version 3.65） and compared with mate－rial object. Finally，the experimental data were analyzed by SPSS 19.0 statistical software. Results：The quality of digital imaging was better in superhard gypsum group than in Esthetic-base and CAM-base group. The observed values of Esthetic-base group，CAM-base group and the real group had no statistical difference in terms of buccal-lingual（P=0.199），and mesial-distal directions（P=0.087），but the observed values of the superhard gypsum group and real group were statistically different（P=0.000，P=0.003）. In addition，the deviation values of superhard gypsum group were greater in mesial-distal directions than in buccal-lingual directions，with statistical－ly significant differences（F=7.310，P=0.000）. The overall offset of superhard gypsum group，Esthetic-base group and CAM-base group were （0.049±0.036），（0.016±0.050） mm and （0.017±0.052） mm，respectively. Conclusion：Under the condition of this ex－periment，the esthetic-base and CAM-base have high accuracy，but superhard gypsum after spraying powder is not recommended due to its inaccuracy.