Wu M T, Tang S X, Peng L Y, Han Y T, Su Y C, Wang X
Department of Implantology and Prosthodontics, Beijing Ruicheng Stomatology Hospital, Beijing Ruicheng Implant Technology College, Beijing 100032, China.
Dental Implant Center, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100033, China.
Zhonghua Kou Qiang Yi Xue Za Zhi. 2021 Jun 9;56(6):570-575. doi: 10.3760/cma.j.cn112144-20210221-00082.
To comparatively evaluate the scan time and the accuracy of maxillary full-arch scans using four intraoral scanners (IOS) on conditions of the intraoral head-simulator and the hand-held model, and to evaluate the influence of different scanning conditions on digital scan. A upper dental arch model with melamine-formaldehyde resin teeth and silica gel gingiva that could be fixed on a head simulator was scanned with an optical scanner (ATOS Core) in order to obtain the standard tessellation language dataset as reference. Intraoral scans were performed on the model fixed on the head simulator by three researchers with four IOS [A: TRIOS 3; B: CS 3600; C: CEREC Omnicam; D: iTero]. For each scanner and each researcher, six scans were performed, to obtain the datasets as the head simulator group. And another six scans with each of the four intraoral scanners were performed by each researcher on the hand-held model to obtain the STL datasets as the hand-held group. The scan time were recorded for each scan. In the Geomagic Wrap software, the digital models were trimmed with only the teeth information retained and supreimposed by best fit alignment function and compared to obtain the root mean square (RMS) values of the discrepancies by three-dimensional compare function. The test datasets of each group were compared with the reference dataset for trueness. The six test scanning datasets with the same scanner of the same researcher were cross compared for precision. Mann Whitney test was used to statistically analyze the difference values of the scan time, trueness and precision of the same intraoral scanner between head simulator group and hand-held group. Compared to the hand-held group, the scan time of A [142(82) s] and D [119(52) s], which two IOS both with handle, were longer in head simulator group [A: 98(28) s; D: 85(22) s] (<0.01). However there were no significant differences between the two groups for scan time of IOS B and C (>0.05). For full-arch scan accuracy (trueness and precision), there were no significant differences between the two groups of IOS A and B (>0.05), while the trueness of C (<0.05) and the precision of D (<0.01) were better in head simulator group [C: 112(38) μm; D: 43(13) μm] compared to hand-held group [C: 135(47) μm; D: 53(18) μm]. However, there were no significant differences for the precision of C (>0.05) and the trueness of D (>0.05). The scan time and the accuracy of full-arch digital scans with different IOS may be effected by the scan conditions. For study of intraoral scanning, head-simulator can simulate the intraoral environment of the real patient to some extent. Meanwhile, the position of the dentist and the patient, and also the limited intraoral space during intraoral scanning are also simulated.
为了在口腔头部模拟器和手持模型条件下，比较评估使用四种口内扫描仪（IOS）进行上颌全牙弓扫描的扫描时间和准确性，并评估不同扫描条件对数字扫描的影响。使用三聚氰胺 - 甲醛树脂牙齿和硅胶牙龈制作了一个可固定在头部模拟器上的上颌牙弓模型，用光学扫描仪（ATOS Core）进行扫描，以获得标准镶嵌语言数据集作为参考。三名研究人员使用四种IOS [A：TRIOS 3；B：CS 3600；C：CEREC Omnicam；D：iTero]对固定在头部模拟器上的模型进行口内扫描。对于每个扫描仪和每个研究人员，进行六次扫描，以获得作为头部模拟器组的数据集。每个研究人员还使用四种口内扫描仪中的每一种对手持模型进行另外六次扫描，以获得作为手持组的STL数据集。记录每次扫描的扫描时间。在Geomagic Wrap软件中，仅保留牙齿信息对数字模型进行修剪，并通过最佳拟合对齐函数进行叠加，然后通过三维比较函数比较以获得差异的均方根（RMS）值。将每组的测试数据集与参考数据集进行真实性比较。对同一研究人员使用相同扫描仪的六个测试扫描数据集进行交叉比较以评估精度。使用Mann Whitney检验对头部模拟器组和手持组之间相同口内扫描仪的扫描时间、真实性和精度的差异值进行统计分析。与手持组相比，两种带有手柄的IOS，即A [142(82) s]和D [119(52) s]，在头部模拟器组中的扫描时间更长 [A：98(28) s；D：85(22) s]（<0.01）。然而，IOS B和C在两组之间的扫描时间没有显著差异（>0.05）。对于全牙弓扫描精度（真实性和精度），IOS A和B两组之间没有显著差异（>0.05），而与手持组 [C：135(47) μm；D：53(18) μm]相比，C的真实性（<0.05）和D的精度（<0.01）在头部模拟器组中更好 [C：112(38) μm；D：43(13) μm]。然而，C的精度（>0.05）和D的真实性（>0.05）没有显著差异。不同IOS进行全牙弓数字扫描的扫描时间和准确性可能受扫描条件影响。对于口内扫描研究，头部模拟器可以在一定程度上模拟真实患者的口腔环境。同时，还模拟了牙医和患者的位置以及口内扫描期间有限的口腔空间。
