二单位式与四单位式种植牙周骨界面应力分布规律差异的三维有限元分析

The varieties of the stress distribution patterns at the bone interface around dental implants between two-unit and four-unit dental implants with three-dimension finite element analysis

为了探讨人工种植牙的数目、上部结构对种植牙周骨界面应力分布的影响，本实验应用三维有限元分析方法，对二单位和四单位式杆式覆盖种植义齿种植牙周骨界面的应力分布规律进行了探讨。结果表明：最大压应力、最大拉应力二单位式与四单位式均位于颈周密质骨，二单位式大于四单位式，两者有显著差异性，（Ｐ＜０．００１）。四单位式最大拉、压应力，远中种植牙要大于近中种植牙。最大位移运动二单位式小于四单位式，四单位式近中种植牙大于远中种植牙。二单位式与四单位式位、压应力主要集中于颈部，其它部位与颈部相比有非常显著的差异性，（Ｐ＜０．０００１）。结论：种植牙数目的增加，可以减小种植牙周颈部密质骨内的最大应力值。四单位式种植义齿颈周骨内应力要小于二单位式种植牙，从这点上看，四单位式种植义齿要优于二单位式种植义齿。多个种植牙种植时，杆的连接，改变了种植牙周骨内的应力分布规律。

In order to investigate The influence of dental implant numbers and superstructure on the stress distribution patterns at the bone interface around dental implants, authors analyzed the varieties of the stress distribution patterns at the bone interface around dental implants between two unit and four unit dental implants using three dimension finite element method. The results showed: The maximum compressive and tensile stresses were located at the cervical bone around dental implant in two unit and four unit dental implants. The stress revealed significantly higher in two unit than four unit implants ( P <0.001). The maximum compressive and tensile stresses of distal implant of four unit dental implants were larger than that of the mesial implant. The maximum motion of displacement of two unit dental implants was less than that of four unit dental implants and the four unit dental implants was higher in the distal implant than the mesial implant. Conclusions suggested that increasing the numbers of implants could decreased maximum compressive and tensile stress level at the cervical bone round the dental implant and when bar connected with the implants the stress was located at the cervical bone round the dental implant.