根上附着体桩柱形态设计对牙本质应力分布的影响

附着体桩柱形态的设计不仅影响到桩柱固位，而且影响牙本质应力分布。本研究用三维有限元法分析临床常见的６种桩柱形态设计对牙本质应力分布的影响。结果表明：锥形桩柱设计对牙本质有楔的作用，其应力值明显高于平行桩柱，为平行桩的１．１倍；螺纹桩柱设计，牙本质最大应力值是非螺纹桩柱的１．０６倍。然而，桩柱形态设计对牙本质应力分布的影响明显小于载荷作用方向对牙本质应力分布的影响。４５度斜向载荷作用下，相同设计的桩柱其牙本质最大应力值是垂直载荷作用下牙本质最大应力值的２．１倍。因此，临床修复设计中，减小侧方咬合力是预防牙本质折裂的主要手段。

Effect of Stud Attachment Post Design on Dentin Stress Distribution

The shape design of attachment post is crucial factors influencing post retention and stress distribution to the dentin. By means of CAD and FEA, the present study investigated the effects of the shape designs of attachment posts on the stress distribution in dentin. The results indicated that the taper post had wedging effects on the dentin and produced higher Von Misses stress than that of parallel side post and the Von Misses stress value of the dentin was about 1.1 times. The maximum Von Misses stress value that the design of the thread post produced was about 1.06 times the stress of the nonthread post did. However, the effects of post design on the dentin were minor compared with the bite force directions. In the same post design, the maximum Von Misses stress in dentin with 45 degree oblique force was about 2.1 times with vertical force. Therefore, reducing oblique force is the main method to prevent root fracture in clinic.