Park Se-Won, Choi Yong-Do, Lee Du-Hyeong
Department of Prosthodontics, School of Dentistry, Kyungpook National University, Daegu, Republic of Korea.
Institute for Translational Research in Dentistry, Kyungpook National University, Daegu, Republic of Korea.
J Adv Prosthodont. 2020 Jun;12(3):107-113. doi: 10.4047/jap.2020.12.3.107. Epub 2020 Jun 18.
The aim of this study was to examine the importance of the defect-free scanning of a scan body by assessing the accuracy of virtual implant positioning in computer-aided design (CAD) software when the scan body image is improperly scanned.
A scan body was digitized in a dentiform model using an intraoral scanner, and scanned images with differing levels of image deficiency were generated: 5%, 10%, and 15% deficiency in the flat or rounded area. Using a best-fit image matching algorithm on each of the deficient scan body images, corresponding virtual implants were created. The accuracy of the implant position was evaluated by comparing the linear and angular discrepancies between the actual and virtual positions of the implant. Kruskal-Wallis tests and Mann-Whitney U tests with Bonferroni correction were used to determine the statistical differences among the seven scanned image deficiency groups (α=.05).
In general, the linear and angular discrepancies of the implant position in the software increased as the deficiency of the scan body images increased. A 15% scan body image deficiency generated larger discrepancies than deficiency of 5% and 10%. The difference of scan defect position, flat or rounded area, did not affect the accuracy of virtual implant orientation at 5% and 10% deficiency level, but did affect the accuracy at 15% deficiency level.
Deficiencies in the scanned images of a scan body can decrease the accuracy of the implant positioning in CAD software when the defect is large, thus leading to the incorrect fabrication of implant prostheses.
本研究的目的是通过评估在扫描体图像扫描不当的情况下，计算机辅助设计（CAD）软件中虚拟种植体定位的准确性，来检验扫描体无缺陷扫描的重要性。
使用口内扫描仪在牙形模型中对扫描体进行数字化处理，并生成具有不同图像缺陷水平的扫描图像：平面或圆形区域分别有5%、10%和15%的缺陷。对每个有缺陷的扫描体图像使用最佳拟合图像匹配算法，创建相应的虚拟种植体。通过比较种植体实际位置与虚拟位置之间的线性和角度差异来评估种植体位置的准确性。使用Kruskal-Wallis检验和经Bonferroni校正的Mann-Whitney U检验来确定七个扫描图像缺陷组之间的统计学差异（α=0.05）。
总体而言，软件中种植体位置的线性和角度差异随着扫描体图像缺陷的增加而增大。扫描体图像有15%的缺陷时产生的差异比5%和10%缺陷时更大。扫描缺陷位置（平面或圆形区域）的差异在5%和10%缺陷水平时不影响虚拟种植体方向的准确性，但在15%缺陷水平时会影响准确性。
当扫描体扫描图像的缺陷较大时，会降低CAD软件中种植体定位的准确性，从而导致种植体假体制作错误。
