Kong Liang, Sun Yingying, Hu Kaijin, Liu Yanpu, Li Dehua, Qiu Zhihui, Liu Baolin
Department of Oral and Maxillofacial Surgery, School of Stomatology, The Fourth Military Medical University, Xi'an 710072, PR China.
J Biomech. 2008;41(5):1124-30. doi: 10.1016/j.jbiomech.2007.12.013. Epub 2008 Feb 6.
In this paper, effects of the implant neck taper and the implant-end fillet on the maximum Von Mises stresses were evaluated in jaw bones, and maximum displacements examined in an implant-abutment complex by a finite element method (FEM). The implant-neck tapers (T) ranged from 45 degrees to 70 degrees , and fillets of implant ends (R) ranged from 0.5 to 1.5mm. Results suggested that under axial load by the maximum Von Mises stresses in cortical and cancellous bones decreased by 71.6% and 14.8%, respectively, and under 45 degrees buccolingual load by 68.2% and 11.0%, respectively. The maximum displacement of implant-abutment complex decreased by 9.1% and 22.8% under axial and 45 degrees buccolingual load, respectively. When T ranged from 64 degrees to 73 degrees and R exceeded 0.8mm, minimum stress/displacement was obtained and the evaluating targets were more sensitive to T than to R. Data indicated that the taper of implant neck favored stress distribution in cortical bones more than the fillet of implant end did; taper of implant neck affected implant stability more than the fillet of implant end did; and the taper of implant neck of 64-73 degrees and fillet of implant end exceeding 0.8mm were optimal selections for the type B/2 bone in a cylinder implant by biomechanical consideration.
本文采用有限元方法（FEM），评估了种植体颈部锥度和种植体末端圆角对颌骨中最大冯·米塞斯应力的影响，并在种植体-基台复合体中检测了最大位移。种植体颈部锥度（T）范围为45度至70度，种植体末端圆角（R）范围为0.5至1.5毫米。结果表明，在轴向载荷下，皮质骨和松质骨中的最大冯·米塞斯应力分别降低了71.6%和14.8%；在45度颊舌向载荷下，分别降低了68.2%和11.0%。种植体-基台复合体的最大位移在轴向和45度颊舌向载荷下分别降低了9.1%和22.8%。当T范围为64度至73度且R超过0.8毫米时，可获得最小应力/位移，且评估指标对T的敏感性高于对R的敏感性。数据表明，种植体颈部锥度比种植体末端圆角更有利于皮质骨中的应力分布；种植体颈部锥度比种植体末端圆角对种植体稳定性的影响更大；从生物力学角度考虑，对于圆柱状种植体中的B/2型骨，64 - 73度的种植体颈部锥度和超过0.8毫米的种植体末端圆角是最佳选择。
