一段式螺旋形种植体有限元应力分析

Stress analysis of one-piece spiral implant

目的 :明确一段式单桩螺旋形种植体的长度、直径、强度、结构与应力的关系并指导种植体的设计与运用。方法 :模型为皮质骨厚度 :1～ 2 mm,种植体与牙槽骨直接相接触。种植体为单桩一段式圆柱形 ,规格为4 mm× 10 mm,3 .9mm× 10 mm,3 .8mm× 12 mm,3 .8× 13 mm,3 .7mm× 12 mm,3 .7× 13 mm,3 .6mm× 14 m m。种植体冠高 4 mm和 9mm。加载方式为垂直、4 5°斜向、4 5°偏心斜向。力量为 2 0 0 N。牙槽骨形态 :用 CT取自一正常牙合形、无附着丧失的青年男性下颌第一磨牙、上颌切牙周围的骨形态。结果 :在载荷一定的情况下 ,除后牙偏心斜向加载外 ,前、后牙种植体自身承受的应力大小与其直径、长度均成反比 ;应力分布范围和大小与受力方式、骨的弹性模量有关。在 4种工况条件下种植体颈部始终是最大应力的部位。种植体上的孔洞是应力集中点之一。提高种植体弹性模量可以降低皮质骨和松质骨的应力。结论 :根据骨形态选择合适直径和长度的种植体有助于提高种植成功率。

砄bjecat:To study the correlatiom between stress and structure of one piece spiral implant.Methods: The morphology of alveolar bone was selected by CT around the first molar of mandible and around the incisor of maxilla of a healthy man in the position of normal occlusion. Cortical bone with the thickness of 1～2 mm was used to make the alveolar bone model. The one piece spiral implants with root, in the shape of cylinder, length of 10,12, 13 and 14 mm, corona height of 4 and 9 mm,diameter of 3.6,3.7, 3.8,3.9 and 4.0 mm were prepared respectively. The implants were put into the alveolar bone models and a load of 200 N was applied vertically, or 45 ℃ obliquely or 45℃ non center obliquely. The stress on the implants was measured and studied with 3D FEM. Results:The stress on the implants was inversely correlated to the length and diameter in the place of front teeth and molars except non centeraly obliquely loading to molar. The greatest stress was found around the neck of the implants. The distribution and intensity of the stress were related to the way of loading and the elastic modulus of bone. Conclusion:The length and diameter of one piece implant are the factors correlated to the stress on the implant and surrounding bone.