Jemaa Hassen, Eisenburger Michael, Greuling Andreas
Department of Prosthetic Dentistry and Biomedical Materials Science, Hannover Medical School, 30625 Hannover, Germany.
Dent J (Basel). 2024 Dec 4;12(12):394. doi: 10.3390/dj12120394.
This study aimed to develop an algorithm for modelling tooth-tooth or implant-implant support configurations for a given 4-unit fixed partial denture (FPD). : The algorithm was implemented in Rhinoceros/Grasshopper to automatically generate geometries with varying bone loss (0 mm to 3 mm), support type (tooth-tooth and implant-implant support) and bone quality (D1 to D4) for a 4-unit FPD. Afterward, a finite element analysis was carried out with a load applied to the central connector of the FPD. Stresses in the FPD and the bone around the support were analysed. : The results indicated that stresses in the bone were influenced by both the depth of bone loss and bone quality across both support types. The maximum stress in the tested FPD models for tooth-tooth support was not significantly influenced by bone quality; instead, the stress peaks were primarily influenced by the depth of bone loss. For D1 bone, the stresses in FPD and bone increased by 4.79% and 8.86%, respectively, for tooth-tooth support and about 32.67% and 100.96%, respectively, for implant-implant support. : The proposed algorithm allows for the automatic, parametrised generation of support for 4-unit fixed partial dentures, which can be used to predict the effect of bone loss and bone quality on stresses for patient-specific geometries. The optimal treatment for support type should be adapted to the patient's specific needs to ensure long-term stability. A decision support involving automatic modelling, e.g., of support, and simulation might improve clinical treatment planning from a long-term perspective.
本研究旨在开发一种算法,用于为给定的4单位固定局部义齿(FPD)建立牙-牙或种植体-种植体支持结构的模型。该算法在Rhinoceros/Grasshopper中实现,以自动生成具有不同骨丢失量(0毫米至3毫米)、支持类型(牙-牙和种植体-种植体支持)和骨质量(D1至D4)的4单位FPD的几何形状。随后,对FPD的中央连接器施加负载进行有限元分析。分析了FPD及其周围骨中的应力。结果表明,两种支持类型下,骨中的应力均受骨丢失深度和骨质量的影响。在测试的牙-牙支持FPD模型中,最大应力受骨质量的影响不显著;相反,应力峰值主要受骨丢失深度的影响。对于D1骨,牙-牙支持时FPD和骨中的应力分别增加4.79%和8.86%,种植体-种植体支持时分别增加约32.67%和100.96%。所提出的算法允许自动、参数化地生成4单位固定局部义齿的支持结构,可用于预测骨丢失和骨质量对特定患者几何形状应力的影响。支持类型的最佳治疗应根据患者的具体需求进行调整,以确保长期稳定性。从长期角度来看,涉及自动建模(如支持结构建模)和模拟的决策支持可能会改善临床治疗计划。