Dental Academy for Continuing Professional Development, Lorenzstraße 7, 76135, Karlsruhe, Germany.
Department of Prosthodontics, University of Würzburg, Würzburg, Germany.
Clin Oral Investig. 2024 Apr 1;28(4):233. doi: 10.1007/s00784-024-05637-y.
Reconstruction of a three-dimensional jaw position determined by a bite recording is an important aspect of prosthetic therapy. Different materials are used for this purpose. In the dental technical workflow, recordings are used to mount a lower jaw cast in a patient-like spatial position relative to the upper jaw cast. We evaluated the accuracy of positioning under the influence of different jaw positions and materials.
In an experimental setup, comprising an articulator, a pair of metal casts, and an optoelectronic measurement system, the spatial position of the incisal point and two condylar points were measured. To evaluate the accuracy of repeated repositioning of casts in the technical workflow, 324 measurements were taken from 108 recordings, consisting of silicone bite-stops made of addition curing silicone with 95 shore hardness, acrylic wafers, and wax recordings. The recordings were obtained in four jaw relations differing in vertical and protrusive components.
Of the three materials/material combinations examined, silicone showed the most consistent results across all measurements, followed by the acrylic wafer system, and then wax recordings. Generally, recordings with smaller gaps between the jaws and no protrusive components showed greater deviations compared to jaw positions with greater protrusion and higher vertical dimensions.
To achieve reliable model mounting with high accuracy, recordings should include the use of a frontal jig and four small recording platelets made of silicone, especially if only a slight elevation of the vertical dimension is needed.
通过咬合记录重建三维颌位是修复治疗的重要方面。为此目的使用了不同的材料。在牙科技术工作流程中,记录用于将下颌模型以类似于患者的空间位置安装在上颌模型上。我们评估了不同颌位和材料影响下的定位准确性。
在一个由关节仪、一对金属模型和光电测量系统组成的实验装置中,测量了切牙点和两个髁突点的空间位置。为了评估在技术工作流程中重复定位模型的准确性,从由 95 肖氏硬度加成固化硅橡胶制成的硅橡胶咬合止动器、丙烯酸片和蜡记录中获取的 108 个记录中进行了 324 次测量。记录包括垂直和突出分量不同的四种颌位关系。
在所检查的三种材料/材料组合中,硅橡胶在所有测量中表现出最一致的结果,其次是丙烯酸片系统,然后是蜡记录。通常,颌间间隙较小且无突出分量的记录与具有较大突出和较高垂直尺寸的颌位相比,偏差更大。
为了实现具有高精度的可靠模型安装,记录应包括使用前夹具和四个由硅橡胶制成的小记录片,尤其是在仅需要轻微升高垂直尺寸的情况下。