Department of Conservative Dentistry and Prosthodontics, Faculty of Odontology, University Complutense of Madrid, Madrid, Spain.
Department of Conservative Dentistry and Prosthodontics, Faculty of Odontology, University Complutense of Madrid, Madrid, Spain; Department of Reconstructive Dentistry and Gerodontology, University of Bern, Bern, Switzerland.
J Dent. 2024 Jun;145:104939. doi: 10.1016/j.jdent.2024.104939. Epub 2024 Mar 21.
To measure the impact of superimposition methods and the designated comparison area on accuracy analyses of dentate models using an ISO-recommended 3-dimensional (3D) metrology-grade inspection software (Geomagic Control X; 3D Systems; Rock Hill, South Carolina; USA).
A dentate maxillary typodont scanned with a desktop scanner (E4; 3 Shape; Copenhagen; Denmark) and an intraoral scanner (Trios 4; 3 Shape; Copenhagen; Denmark) was used as reference. Eight groups were created based on the core features of each superimposition method: landmark-based alignment (G1); partial area-based alignment (G2); entire tooth area-based alignment (G3); double alignment combining landmark-based alignment with entire tooth area-based alignment (G4); double alignment combining partial area-based alignment with entire tooth area-based alignment (G5); initial automated quick pre-alignment (G6); initial automated precise pre-alignment (G7); and entire model area-based alignment (G8). Diverse variations of each alignment and two regions for accuracy analyses (teeth surface or full model surface) were tested, resulting in a total of thirty-two subgroups (n = 18). The alignment accuracy between experimental and reference meshes was quantified using root mean square (RMS) error as trueness and its repeatability as precision. The descriptive statistics, a factorial repeated measures analysis of variance (ANOVA) and a post hoc Tuckey multiple comparison tests were used to analyze the trueness, and precision (α = 0.05).
A total of 576 superimpositions were performed. The unique partial area-based superimposition method demonstrated the least precise alignment and was the sole group to exhibit a significant difference (p<.001). Automated initial pre-alignments demonstrated similar accuracy to other superimposition methods (p>.05). Double alignments did not result in accuracy improvement (p>.05). The designated comparison area displayed differences in both trueness (p<.001) and precision (p<.001), leading to an overall discrepancy of 8 ± 4 μm between selecting the teeth surface or full model surface.
The superimposition method choice within the tested software did not impact accuracy analyses, except when the alignment relies on a unique and reduced area, such as the palatal rugae, a single tooth, or three adjacent teeth on one side.
The superimposition method choice within the tested ISO-recommended 3D inspection software did not impact accuracy analyses.
使用 ISO 推荐的三维（3D）计量级检测软件（Geomagic Control X；3D Systems；南卡罗来纳州罗克希尔；美国），测量叠加方法和指定比较区域对牙模型精度分析的影响。
以使用桌面扫描仪（E4；3Shape；哥本哈根；丹麦）和口内扫描仪（Trios 4；3Shape；哥本哈根；丹麦）扫描的牙上颌模型为参考。基于每种叠加方法的核心特征创建了 8 组：基于标志点的对齐（G1）；基于部分区域的对齐（G2）；基于整个牙齿区域的对齐（G3）；结合基于标志点的对齐和基于整个牙齿区域的对齐的双重对齐（G4）；结合基于部分区域的对齐和基于整个牙齿区域的对齐的双重对齐（G5）；初始自动快速预对齐（G6）；初始自动精确预对齐（G7）；以及基于整个模型区域的对齐（G8）。测试了每种对齐方式的多种变化和两个精度分析区域（牙齿表面或全模型表面），共产生 32 个子组（n=18）。使用均方根（RMS）误差作为准确度，其重复性作为精密度，对实验网格和参考网格之间的对准精度进行量化。使用析因重复测量方差分析（ANOVA）和事后 Tukey 多重比较检验来分析准确度和精密度（α=0.05）。
共进行了 576 次叠加。独特的基于部分区域的叠加方法显示出最低的精确对准，并且是唯一表现出显著差异的组（p<.001）。自动初始预对齐与其他叠加方法具有相似的准确性（p>.05）。双重对齐没有提高精度（p>.05）。指定的比较区域在准确性上存在差异（p<.001），导致选择牙齿表面或全模型表面之间存在 8±4μm 的总体差异。
在所测试软件中，除了依赖于独特且缩小的区域（如腭皱、单个牙齿或一侧的三个相邻牙齿）的对齐方式外，叠加方法的选择不会影响精度分析。
在所测试的 ISO 推荐的 3D 检测软件中，叠加方法的选择不会影响精度分析。
