Former Graduate student, Yonsei University College of Dentistry, Seoul, Republic of Korea.
Clinical Assistant Professor, Department of Prosthodontics, Gangnam Severance Dental Hospital, Yonsei University College of Dentistry, Seoul, Republic of Korea.
J Prosthet Dent. 2023 Oct;130(4):612.e1-612.e8. doi: 10.1016/j.prosdent.2023.07.028. Epub 2023 Aug 24.
Although intraoral scanners (IOSs) are popular, few studies have evaluated the accuracy of digital mounting by using IOSs.
The purpose of this in vitro study was to compare the accuracy of digital mounting by using 2 IOSs and 2 occlusal scanning methods.
Fourteen Ø5-mm zirconia balls were attached approximately 5 mm apical to the free gingival margin of both second molars, second premolars, and canines and between the central incisors in maxillary and mandibular epoxy casts. A polyetheretherketone hexagonal cube with a 10-mm-long edge was attached to the buccal side of the missing mandibular right first molar area, and the cube was used to set a part coordinate system. Two IOSs (TRIOS 3, Primescan) were used to assess the intra-arch and interarch accuracies. For intra-arch assessment, each IOS was used to digitally scan the mandibular epoxy cast 15 times and fabricate 15 datasets. The deviation of each zirconia ball centroid was statistically compared between the IOSs. For interarch assessment, each IOS was used to digitally scan the maxillary and mandibular epoxy casts, and the data were digitally mounted by using a single anterior occlusal scan (A) or bilateral posterior occlusal scan (P). Both occlusal scans were performed 15 times; therefore, 4 groups (15 datasets per group) of mounted digital datasets were assigned. The deviation of each maxillary zirconia ball centroid, as well as the interarch distance between the corresponding maxillary and mandibular zirconia ball centroids, were compared among the 4 groups. For statistical analysis, the Mann-Whitney U test and Kruskal-Wallis test with Bonferroni correction were used (α=.05).
Primescan had less deviation than TRIOS 3 in the complete arch scan. When the zirconia balls were close to the origin, the bilateral posterior occlusal scan produced less deviation of their centroids. Primescan produced decreased interarch distance in the anterior and posterior dentition, while TRIOS 3 produced increased interarch distance in the anterior dentition and decreased interarch distance in the posterior dentition.
A significant difference was noted in intra-arch accuracy between the IOSs, and the difference influenced the digital mounting accuracy. The type of occlusal scan and IOS significantly influenced the accuracy of digital mounting. Both IOSs produced decreased interarch distances in the second molar area.
尽管口内扫描仪（IOS）很受欢迎，但很少有研究评估使用 IOS 进行数字印模的准确性。
本体外研究的目的是比较两种 IOS 和两种咬合扫描方法进行数字印模的准确性。
将 14 个直径为 5mm 的氧化锆球附着于上下颌第二磨牙、第二前磨牙和尖牙的游离龈缘上方约 5mm 处，以及上颌和下颌的环氧模型中两个中切牙之间。一个具有 10mm 长边缘的聚醚醚酮六方棱柱体被附着于下颌右侧第一磨牙缺失区的颊侧，该棱柱体用于建立一个局部坐标系。使用两种 IOS（TRIOS 3、Primescan）来评估弓内和弓间的准确性。对于弓内评估，每个 IOS 都用于数字化扫描下颌环氧模型 15 次，以制作 15 个数据集。在 IOS 之间统计比较每个氧化锆球质心的偏差。对于弓间评估，每个 IOS 用于数字化扫描上颌和下颌的环氧模型，通过单次前牙咬合扫描（A）或双侧后牙咬合扫描（P）来进行数字印模。两次咬合扫描各进行 15 次，因此分配了 4 组（每组 15 个数据集）的数字化印模数据集。比较了 4 组中每个上颌氧化锆球质心的偏差，以及相应的上颌和下颌氧化锆球质心之间的牙弓间距离。统计分析采用 Mann-Whitney U 检验和 Kruskal-Wallis 检验（Bonferroni 校正）（α=.05）。
在全弓扫描中，Primescan 的偏差小于 TRIOS 3。当氧化锆球接近原点时，双侧后牙咬合扫描产生的质心偏差较小。Primescan 在前后牙列中产生较小的牙弓间距离，而 TRIOS 3 在前牙列中产生较大的牙弓间距离，而后牙列中则产生较小的牙弓间距离。
IOS 之间的弓内准确性存在显著差异，这种差异影响了数字印模的准确性。咬合扫描类型和 IOS 显著影响了数字印模的准确性。两种 IOS 都在第二磨牙区产生了较小的牙弓间距离。
