Associate Professor and Director of Postgraduate Program of Advanced in Implant-Prosthodontics, Department of Conservative Dentistry and Prosthodontics, School of Dentistry, Complutense University of Madrid, Madrid, Spain.
PhD Candidate and Postgraduate Resident in Advanced in Implant-Prosthodontics, Department of Conservative Dentistry and Prosthodontics, School of Dentistry, Complutense University of Madrid, Madrid, Spain.
J Prosthet Dent. 2024 Jan;131(1):119-127. doi: 10.1016/j.prosdent.2021.11.018. Epub 2022 Mar 23.
The accuracy of digital implant scans can be affected by the implant angulation, implant depth, or interimplant distance. However, studies analyzing intraoral scanning accuracy with different implant angulations and different scan body heights are scarce.
The purpose of this in vitro study was to determine the influence of the implant angulation and clinical implant scan body height on the accuracy of complete arch scans.
Two definitive implant casts with 6 implant analogs (Zimmer Biomet) were obtained: 1 cast had all the implant analogs parallel (GP group), and 1 cast had the implant analogs with divergence of up to 30 degrees (GD group). A coordinate measurement machine (Global Evo 09.15.08) was used to measure the positions of the implant analogs. Each group was divided into 3 subgroups depending on the clinical implant scan body height: 10, 6, and 3 mm. An implant scan body (Elos Accurate Scan Body Brånemark system) was positioned on each implant analog. A total of 10 scans of each subgroup were recorded by using an intraoral scanner (TRIOS 3). Each STL file obtained was imported into a reverse engineering software program (Geomagic), and linear and angular Euclidean measurements were obtained. The Euclidean calculations between the implant analog positions of the definitive implant casts were used as a reference to calculate the discrepancies among the corresponding subgroups. The Kolmogorov-Smirnov test revealed that the lineal measurements were not normally distributed, so the Kruskal-Wallis and pairwise comparison Dunn tests were used (α=.05). The Kolmogorov-Smirnov test revealed that the angular measurements were normally distributed. Therefore, the 2-way ANOVA and pairwise comparison Tukey tests were used (α=.05).
The Kruskal-Wallis test revealed significant differences in the linear Euclidean medians between the GP and GD groups with different clinical implant scan body heights (H(5)=23.18, P<.001). Significant differences in the linear Euclidean medians were computed between the GP-6 and GD-10 subgroups (P=.009), GD-3 and GD-6 subgroups (P=.029), and GD-3 and GD-10 subgroups (P=.001). Two-way ANOVA revealed that the implant angulation (F(1, 3.3437)=28.93, P<.001) and clinical implant scan body height (F(2, 0.4358)=3.77, P=.029) were significant predictors of discrepancies in the angular measurement.
Implant angulation and clinical scan body height influenced scanning accuracy. The lowest clinical implant scan body height tested had the lowest accuracy in both parallel and angled implants, but statistically significant differences were found only in the angled group.
植入物的角度、植入物的深度或植入物之间的距离会影响数字植入物扫描的准确性。然而，分析不同植入物角度和不同扫描体高度的口腔内扫描准确性的研究很少。
本体外研究的目的是确定植入物角度和临床植入扫描体高度对全弓扫描准确性的影响。
获得了 2 个带有 6 个种植体模拟物的确定性种植体模型（Zimmer Biomet）：1 个模型中的所有种植体模拟物均平行（GP 组），1 个模型中的种植体模拟物具有最大 30 度的发散角度（GD 组）。使用坐标测量机（Global Evo 09.15.08）测量种植体模拟物的位置。每组根据临床植入扫描体高度进一步分为 3 个子组：10、6 和 3mm。在每个种植体模拟物上定位植入扫描体（Elos Accurate Scan Body Brånemark 系统）。使用口腔内扫描仪（TRIOS 3）记录每个子组的 10 次扫描。将获得的每个 STL 文件导入逆向工程软件程序（Geomagic），并获得线性和角度欧式测量值。确定性种植体模型中种植体模拟物位置的欧式计算被用作计算相应子组之间差异的参考。柯尔莫哥洛夫-斯米尔诺夫检验表明线性测量值呈非正态分布，因此使用克鲁斯卡尔-沃利斯和两两比较邓恩检验（α=.05）。柯尔莫哥洛夫-斯米尔诺夫检验表明角度测量值呈正态分布。因此，使用双向方差分析和两两比较图基检验（α=.05）。
克鲁斯卡尔-沃利斯检验显示，不同临床植入扫描体高度下 GP 和 GD 组的线性欧几里得中位数存在显著差异（H(5)=23.18，P<.001）。GP-6 和 GD-10 子组（P=.009）、GD-3 和 GD-6 子组（P=.029）以及 GD-3 和 GD-10 子组（P=.001）之间的线性欧几里得中位数存在显著差异。双向方差分析表明，植入物角度（F(1, 3.3437)=28.93，P<.001）和临床植入扫描体高度（F(2, 0.4358)=3.77，P=.029）是角度测量差异的显著预测因素。
植入物角度和临床扫描体高度会影响扫描准确性。测试的最低临床植入扫描体高度在平行和倾斜植入物中均具有最低的准确性，但仅在倾斜组中发现了统计学上的显著差异。
