Center of Digital Dentistry, Faculty of Prosthodontics, Peking University School and Hospital of Stomatology & National Center of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Research Center of Oral Biomaterials and Digital Medical Devices & Beijing Key Laboratory of Digital Stomatology & Shanxi Province Key Laboratory of Oral Diseases Prevention and New Materials, Beijing, PR China.
Department of Prosthodontics, Peking University School and Hospital of Stomatology & National Center of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Research Center of Oral Biomaterials and Digital Medical Devices & Beijing Key Laboratory of Digital Stomatology & Shanxi Province Key Laboratory of Oral Diseases Prevention and New Materials, Beijing, PR China.
Comput Biol Med. 2022 Jul;146:105564. doi: 10.1016/j.compbiomed.2022.105564. Epub 2022 Apr 29.
To evaluate the effect of guiding structure and 3D-printing material of CAD-CAM guides on the accuracy of guiding planes preparation.
Four types of computer-aided design and computer-aided manufacturing (CAD-CAM) guides for preparing guiding planes of removable partial denture (RPD) were designed in two types of guiding structures (triple-constraint and single-plane constraint) and were 3D printed using resin and cobalt-chromium (Co-Cr) alloy. Guiding plane preparation of identical resin casts was performed using CAD-CAM guides (resin template, metal template, resin guided device, and metal guide device) in four test groups and by freehand in the control group (n = 22 per group). All prepared casts were then scanned (Test) and aligned to the reference cast with designed guiding planes. 3D compare analysis was performed and root-mean-square (RMS) values were calculated for assessing the 3D trueness and 3D precision of guiding plane preparation. The angle between the prepared guiding plane (Test) and the designed path of placement of RPD (Reference) was measured for evaluating the direction trueness.
RMS values of the metal template group for 3D trueness (39.7 ± 14.6 μm) and 3D precision (28.6 ± 6.8 μm) were significantly lower than that of other groups (p < .05). For direction trueness, the metal template group showed the least angle deviation (1.09 ± 0.56°), and the freehand group demonstrated the largest angle deviation (7.03 ± 2.83°).
The Co-Cr alloy guides with triple-constraint guiding structure can assist to prepare accurate guiding planes of RPD.
评估 CAD-CAM 导板的引导结构和 3D 打印材料对引导平面制备精度的影响。
设计了两种引导结构（三约束和单平面约束）的四种用于制备可摘局部义齿（RPD）引导平面的计算机辅助设计和计算机辅助制造（CAD-CAM）导板，并使用树脂和钴铬（Co-Cr）合金进行 3D 打印。在四个实验组中，使用 CAD-CAM 导板（树脂模板、金属模板、树脂导向装置和金属导向装置）和对照组（每组 22 个）的自由手在相同的树脂模型上进行引导平面制备。所有制备的模型均进行扫描（测试）并与具有设计引导平面的参考模型对齐。进行 3D 比较分析，并计算均方根（RMS）值，以评估引导平面制备的 3D 准确性和 3D 精度。测量制备的引导平面（测试）与 RPD 放置设计路径（参考）之间的角度，以评估方向准确性。
金属模板组在 3D 准确性（39.7 ± 14.6μm）和 3D 精度（28.6 ± 6.8μm）方面的 RMS 值明显低于其他组（p <.05）。对于方向准确性，金属模板组的角度偏差最小（1.09 ± 0.56°），而自由手组的角度偏差最大（7.03 ± 2.83°）。
三约束引导结构的 Co-Cr 合金导板可辅助制备 RPD 的准确引导平面。
