Objective: To compare the accuracy of intraoral scanning for complete-arch implant-supported fixed prosthesis using umbrella scan bodies (USB) and conventional scan bodies (CSB), providing a reference for the clinical application of umbrella-shaped scanning bodies. Methods: A new type of umbrella-shaped scanning body and its matching auxiliary bar were independently developed. A maxillary type Ⅳ dental stone model with six parallel implant abutment analogs was fabricated. Conventional scanning bodies were installed on the model, and a laboratory scanner was used to scan the model as reference data. The CSB, USB, and USB combined with an auxiliary bar (U+SB) were installed on the model, respectively. A single attending physician performed intraoral scanning 10 times for each group using an intraoral scanner, serving as test group data (CSB, USB, U+SB). The test data were best-fit aligned with the virtual abutment models generated from the reference data. The trueness and precision of root-mean-square error (RMSE) values, inter-abutment distance deviations, angular deviations, and scanning time were measured and calculated. Repeated measures ANOVA and generalized estimating equation models were used for statistical analysis. Results: The trueness of RMSE values [(48.0±12.6) and (45.9±13.4) μm] and distance deviations [(64.5±60.2) and (63.8±54.4) μm] of the USB and U+SB groups were significantly better than those of the CSB group [(81.9±23.9) and (90.0±85.2) μm] (all P<0.05). There was no significant difference in trueness of RMSE values and distance deviations between the USB group and U+SB group (all P>0.05). There were no significant differences in the precision of RMSE values and angular deviations among the three groups (all P>0.05). The scanning time of the USB group and U+SB group [(54.3±11.8) and (35.8±10.1) s] was significantly shorter than that of CSB group [(108.7±38.9) s] (all P<0.05). Conclusions: Compared with conventional scanning bodies, the new umbrella-shaped scanning body demonstrates higher accuracy and efficiency for intraoral scanning impressions in complete-arch implant-supported fixed prosthesis.
目的： 探讨全牙弓种植固定修复过程中常规扫描杆、伞形扫描杆、伞形扫描杆结合辅助杆辅助下口内扫描的精度差异，以期为伞形扫描杆的临床应用提供参考。 方法： 自主研发1种新型伞形扫描杆以及配套辅助杆。制作带有6个平行种植体复合基台替代体的上颌超硬石膏模型1个。于石膏模型上安装常规扫描杆，采用牙颌模型扫描仪进行模型扫描作为参考数据。将常规扫描杆、伞形扫描杆、伞形扫描杆结合辅助杆分别安装于石膏模型上，由1名主治医师采用口内扫描仪分别重复扫描10次，作为实验组数据（常规扫描杆组、伞形扫描杆组、伞形扫描杆结合辅助杆组）。将实验组数据与参考数据生成的虚拟基台模型进行最佳拟合配准，测量并计算分别代表正确度和精密度的均方根误差（RMSE）值及各实验组基台间距离偏差和角度偏差，以及扫描时间。采用重复测量的方差分析和广义估计方程模型进行统计学分析。 结果： 伞形扫描杆组和伞形扫描杆结合辅助杆组正确度RMSE值［（48.0±12.6）和（45.9±13.4）μm］和距离偏差［（64.5±60.2）和（63.8±54.4）μm］均显著优于常规扫描杆组［（81.9±23.9）和（90.0±85.2）μm］（均P<0.05），伞形扫描杆组和伞形扫描杆结合辅助杆组正确度RMSE值和距离偏差差异均无统计学意义（均P>0.05）。3组精密度RMSE值和角度偏差差异均无统计学意义（均P>0.05）。伞形扫描杆组和伞形扫描杆结合辅助杆组扫描时间［（54.3±11.8）和（35.8±10.1）s］均显著小于常规扫描杆组［（108.7±38.9）s］（均P<0.05）。 结论： 相比常规扫描杆，新型伞形扫描杆在针对全牙弓种植固定修复进行口内扫描时，具有更高的精准度与效率。.