Sousa Ravel M, Simamoto-Junior Paulo Cézar, Fernandes-Neto Alfredo Júlio, Sloten Jos Vander, Jaecques Siegfried Vn, Pessoa Roberto S
Int J Oral Maxillofac Implants. 2016 Jul-Aug;31(4):750-60. doi: 10.11607/jomi.4785.
To evaluate the influence of different implant numbers and connection types on the biomechanical behavior of mandibular full-arch implant-supported rehabilitation.
Computed tomography-based finite element models comprising a totally edentulous mandible and 3.8 × 13-mmdiameter implants, abutments, abutment screws, bar retaining screw, and bar were constructed. Different implant numbers (three, four, and five implants) and loading conditions (symmetrical/balanced, unilateral, and posterior with diverse loading magnitudes) were simulated for both external hex and Morse-taper connections. The peak equivalent strain (EQV strain) in the bone and the peak of von Mises stress (EQV stress) in the abutment screw and bar retaining screw were evaluated.
Lower strain values were observed for a symmetrical loading distribution. Considering the same loading conditions, significantly higher bone strain levels were observed for external hex, compared with the Morse-taper connection. The number of implants had no significant influence on strain levels in bone, irrespective of the connection types. Compared with the external hex connection, the Morse-taper connection type presented significantly lower EQV stress values in abutment screws, but significantly higher stress in the bar retaining screw. Increasing the number of implants significantly reduced the EQV stress in the abutment screw and bar retaining screw.
The Morse-taper connection type significantly decreased the strain levels in peri-implant bone, while increasing the stress in bar retaining screws. A smaller number of implants in an inferior full-arch rehabilitation slightly increased the stress in the abutment and bar retaining screws. Balanced adjustments of the loading improve the biomechanics of a mandibular full-arch rehabilitation.
评估不同种植体数量和连接类型对下颌全牙弓种植体支持修复体生物力学行为的影响。
构建基于计算机断层扫描的有限元模型，包括完全无牙的下颌骨以及直径为3.8×13 mm的种植体、基台、基台螺钉、杆卡固位螺钉和杆。针对外六角连接和莫氏锥度连接，模拟了不同的种植体数量（3颗、4颗和5颗种植体）和加载条件（对称/平衡、单侧以及不同加载大小的后部加载）。评估了骨中的峰值等效应变（EQV应变）以及基台螺钉和杆卡固位螺钉中的冯·米塞斯应力峰值（EQV应力）。
对称加载分布时观察到较低的应变值。在相同加载条件下，与莫氏锥度连接相比，外六角连接的骨应变水平显著更高。无论连接类型如何，种植体数量对骨中的应变水平均无显著影响。与外六角连接相比，莫氏锥度连接类型在基台螺钉中的EQV应力值显著更低，但在杆卡固位螺钉中的应力显著更高。增加种植体数量显著降低了基台螺钉和杆卡固位螺钉中的EQV应力。
莫氏锥度连接类型显著降低了种植体周围骨中的应变水平，同时增加了杆卡固位螺钉中的应力。在下颌全牙弓修复中种植体数量较少会略微增加基台和杆卡固位螺钉中的应力。均衡调整加载可改善下颌全牙弓修复的生物力学性能。
