Department of Orthodontics and Dentofacial Orthopaedics, Heidelberg University Hospital, Im Neuenheimer Feld 400, Heidelberg, Germany.
Department of Prosthodontics, Heidelberg University Hospital, University of Heidelberg, Im Neuenheimer Feld 400, Heidelberg, Germany.
Sci Rep. 2021 Jul 19;11(1):14719. doi: 10.1038/s41598-021-94237-x.
Manufacturing of Fränkel's functional regulator 3 (FR3) is complicated and requires extensive knowledge from the dental technician. To determine whether FR3s produced by CAD/CAM techniques (CAD-FR3) meet similar mechanical properties like conventional FR3s (Con-FR3), for each of 10 patient cases, three CAD-FR3 designs (palatal connector cross-section 3 × 3 mm, 4 × 1 mm or 5 × 2 mm) and one Con-FR3 were subjected to cyclic loading and subsequent fracture testing in a universal testing device. Transversal load capacity (F) and stiffness were compared among the different CAD-FR3 designs and Con-FR3s using Friedman and Wilcoxon tests with a significance level of α = 0.05. All CAD-FR3 designs had significantly higher mean F (p ≤ 0.007) and stiffness (p ≤ 0.005) than the Con-FR3s. The CAD-FR3 had the highest mean F (98.2 ± 26.2 N) and stiffness (37.1 ± 15.5 N/mm), closely followed by the CAD-FR3 (F: 90.3 ± 24.7 N; stiffness: 30.0 ± 12.3 N/mm). Among the CAD appliances, CAD-FR3 had the lowest values (p ≤ 0.007 for all pairwise tests) with F of 45.8 ± 17.9 N and stiffness of 12.5 ± 7.3 N/mm. CAD-FR3s have superior mechanical properties in comparison to Con-FR3s if certain design parameters are followed. Further clinical investigations have to examine if they can serve as an alternative in practice.
Fränkel 功能性调节器 3（FR3）的制造过程复杂，需要牙科技术人员具备广泛的知识。为了确定 CAD/CAM 技术（CAD-FR3）生产的 FR3 是否具有类似于传统 FR3（Con-FR3）的机械性能，对每个 10 例患者，三种 CAD-FR3 设计（腭侧连接体横截面 3×3mm、4×1mm 或 5×2mm）和一个 Con-FR3 进行了循环加载和随后在万能试验机中的断裂测试。使用 Friedman 和 Wilcoxon 检验，在显著性水平α=0.05 下比较不同 CAD-FR3 设计和 Con-FR3 的横向承载能力（F）和刚度。所有 CAD-FR3 设计的平均 F（p≤0.007）和刚度（p≤0.005）均显著高于 Con-FR3s。CAD-FR3 的平均 F（98.2±26.2N）和刚度（37.1±15.5N/mm）最高，紧随其后的是 CAD-FR3（F：90.3±24.7N；刚度：30.0±12.3N/mm）。在 CAD 器具中，CAD-FR3 的值最低（所有两两比较的 p≤0.007），F 为 45.8±17.9N，刚度为 12.5±7.3N/mm。如果遵循某些设计参数，CAD-FR3 具有比 Con-FR3 更好的机械性能。还需要进一步的临床研究来检验它们在实践中是否可以作为替代物。
