Kong Liang, Liu Bao-Lin, Hu Kai-Jin, Li De-Hua, Song Ying-Liang, Ma Pan, Yang Jin
Dept. of oral and Maxillofacial Surgery, College of Stomatology, The Fourth Military Medical University, Xi'an 710032, China.
Hua Xi Kou Qiang Yi Xue Za Zhi. 2006 Dec;24(6):509-12, 515.
To determine the optimal thread pitch for an experimental cylinder implant in Ansys Work-bench Design Xplorer environment.
Finite element models of segment jaw bone with a V-shaped thread implant were created. The thread pitch (P) was set from 0.5 mm to 1.6 mm. The maximum Equivalent stresses (EQV stresses) in jaw bone and in implant were evaluated.
Under axial load, the amplification of maximum EQV stresses in cortical bone, cancellous bone and implant were 7.1%, 123.4% and 28.7% respectively. Under bucco-lingual load, the amplification of maximum EQV stresses in cortical bone, cancellous bone and implant were 2.8%, 28.8% and 14.9% respectively. When P exceeded 0.8 mm, the response curve curvature of maximum EQV stresses in jaw bone and in implant to P was ranged from -1 to 1.
Stresses in cancellous bone are more sensitive to thread pitch than in cortical bone. Stresses in jaw bone under axial load are easier affected by thread pitch than under bucco-lingual load. Thread pitch plays a greater role in protecting dental implant under axial load than under bucco-lingual load. Thread pitch exceed 0.8 mm should be the optimal design in a cylinder implant, but oversized pitch should be avoided too.
在Ansys Work-bench Design Xplorer环境中确定实验性圆柱种植体的最佳螺距。
创建带有V形螺纹种植体的节段性颌骨有限元模型。螺距（P）设置为0.5毫米至1.6毫米。评估颌骨和种植体中的最大等效应力（EQV应力）。
在轴向载荷下，皮质骨、松质骨和种植体中最大EQV应力的放大倍数分别为7.1%、123.4%和28.7%。在颊舌向载荷下，皮质骨、松质骨和种植体中最大EQV应力的放大倍数分别为2.8%、28.8%和14.9%。当P超过0.8毫米时，颌骨和种植体中最大EQV应力对P的响应曲线曲率范围为-1至1。
松质骨中的应力比皮质骨中的应力对螺距更敏感。轴向载荷下颌骨中的应力比颊舌向载荷下更容易受到螺距的影响。螺距在轴向载荷下对牙种植体的保护作用比颊舌向载荷下更大。螺距超过0.8毫米应是圆柱种植体的最佳设计，但也应避免螺距过大。
