Medical Center - University of Freiburg, Center for Dental Medicine, Department of Prosthetic Dentistry, Faculty of Medicine, University of Freiburg, Hugstetter Str. 55, 79106, Freiburg, Germany; Department of Prosthodontics, Geriatric Dentistry and Craniomandibular Disorders, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Assmanshauser Str. 4-6, 14197, Berlin, Germany.
Medical Center - University of Freiburg, Center for Dental Medicine, Department of Prosthetic Dentistry, Faculty of Medicine, University of Freiburg, Hugstetter Str. 55, 79106, Freiburg, Germany.
J Mech Behav Biomed Mater. 2021 Feb;114:104179. doi: 10.1016/j.jmbbm.2020.104179. Epub 2020 Oct 28.
Occlusal devices to reduce symptoms of bruxism and temperomandibular disorders can nowadays be manufactured in a digital workflow but studies comparing the accuracy of those occlusal devices are still limited. Therefore, the aim of this investigation was to investigate the accuracy of injection molding compared with four computer-aided design (CAD) and computer-aided manufacturing (CAM) techniques for the manufacturing of occlusal devices. In addition, the number of contact points and retention were evaluated to assess clinical relevance. A conventional workflow consisting of alginate impression, wax-up, and injection molding (IM) and digital workflows including intraoral scanning, digital design, and subtractive manufacturing (SM) or additive manufacturing by using stereolithography (SLA), digital light processing (DLP), and material jetting (Polyjet) were investigated. Sixteen splints were fabricated with each method. The intaglio surfaces of the splints were laser scanned and superimposed with the reference data sets to analyze the surface deviations. In addition, the number of contact points after repositioning the splints on the reference model was evaluated with occlusal foil. Finally, the retention was measured in a tensile test. One-way ANOVA with post hoc Tukey tests were used for statistical analyses (α = .05). IM and SM splints demonstrated the highest manufacturing accuracy without significant differences to each other (P > .985). Additive manufactured splints revealed greater deviations with equal results for SLA and Polyjet (P > .949) and significantly higher deviations for DLP compared to all other groups (P < .002). Comparable retention force was measured for IM, SM, and SLA (P > .923), whereas Polyjet splints showed the greatest variability. IM and SM splints presented the most contact points (P = .505). Additive manufactured splints demonstrated fewer contacts without significant difference to each other (P > .116). It can be concluded, that there is no difference in manufacturing accuracy, retention, and number of contacts between IM and SM splints. AM splints demonstrated higher, however, clinically acceptable deviations.
如今，用于减少磨牙症和颞下颌关节紊乱症状的咬合矫治器可以通过数字化工作流程制造，但比较这些咬合矫治器准确性的研究仍然有限。因此，本研究旨在调查注塑与四种计算机辅助设计（CAD）和计算机辅助制造（CAM）技术在制造咬合矫治器方面的准确性。此外，还评估了接触点的数量和保留情况，以评估其临床相关性。研究了包括藻酸盐印模、蜡型和注塑（IM）的传统工作流程以及包括口内扫描、数字设计和减法制造（SM）或使用立体光刻（SLA）、数字光处理（DLP）和材料喷射（Polyjet）的添加剂制造的数字工作流程。使用每种方法制作了 16 个夹板。用激光扫描夹板的凹面，并与参考数据集进行叠加，以分析表面偏差。此外，还通过咬合箔片评估了将夹板重新定位在参考模型上后的接触点数量。最后，在拉伸试验中测量保留力。使用单向方差分析和事后 Tukey 检验进行统计分析（α =.05）。IM 和 SM 夹板的制造精度最高，彼此之间没有显著差异（P >.985）。添加剂制造的夹板显示出更大的偏差，SLA 和 Polyjet 的结果相等（P >.949），与所有其他组相比，DLP 的偏差显著更高（P <.002）。IM、SM 和 SLA 的保留力测量值相当（P >.923），而 Polyjet 夹板的变化最大。IM 和 SM 夹板的接触点最多（P =.505）。添加剂制造的夹板接触点较少，但彼此之间没有显著差异（P >.116）。可以得出结论，IM 和 SM 夹板在制造精度、保留力和接触点数量方面没有差异。然而，AM 夹板的偏差更高，但在临床可接受范围内。
