上颌中切牙种植体的应力改变及骨吸收变化

目的：观察上颌中切牙种植体植入方向在与牙冠长轴不同夹角情况下,种植体骨界面应力变化值和最大安全角度的临界值,以此来指导种植前设计。方法：应用有限元法分析不同倾斜角度对种植体骨界面应力峰值影响。结合临床病例,使用X线头影测量分析,测算出患者理想牙冠长轴的位置,以此轴线与种植体长轴的夹角作为倾斜角度分析在不同角度下种植体的骨界面应力变化和中切牙种植病例的周围骨吸收情况。倾斜角0°-20°范围内边缘骨吸收值和种植体骨界面应力值均在正常范围内,适合使用角度基台修复;倾斜角大于20°或25°以上时,应力值有明显升高趋势,种植体唇侧颈部应力集中区骨吸收明显。结论：建议做牙槽骨改建手术,改变种植体植入角度。

Cervical Zone of Cortical Bone with the Obvious Resorption of the Bone

Objective：To observe the change of he stress on implant and bone interface and the critical point of the maximum security angle under the condition of different angles of the implants direction and dental crowns long axis of the maxillary central incisor so as to guide the implant designs.Methods： The finite element method was used to analyze the change of the stress on implant and bone interface under different angles of the implants direction.We found the ideal position of the long axis of the maxillary central incisors with combining clinical cases and cephalographs.The stress change of implant and bone interface and the marginal bone loss around implants are both analyzed when the angle between the implant and the ideal location of the incisors changes.Results： When the abutment angulations of the maxillary central incisor were between 0 to 20,the marginal bone resorption and the implant-bone-interface stress were normal.But when the abutment angulations of the maxillary central incisor increased to 20 or 25,the implant stress increases sharply.Peak tensile stresses were focused in labial.Conclusions： It is suggested that the alveolar bone remodeling be done and the change of the abutment angulation.