Private practice, Moscow, Idaho.
Am J Orthod Dentofacial Orthop. 2010 Jan;137(1):91-9. doi: 10.1016/j.ajodo.2007.12.034.
The purpose of this study was to determine the effect of miniscrew implant orientation on the resistance to failure at the implant-bone interface.
Miniscrew implants (IMTEC, Ardmore, Okla) were placed in 9 human cadaver mandibles, oriented at either 90 degrees or 45 degrees to the bone surface, and tested to failure in pull-out (tensile) and shear tests. The line of applied force and the orientation of the implants aligned at 45 degrees were either parallel or perpendicular to the maximum axis of bone stiffness. In the shear tests, the implants aligned at 45 degrees were angled toward and opposing the axis of shear force.
The implants aligned at 90 degrees had the highest force at failure of all the groups (342 + or - 80.9 N; P <0.001). In the shear tests, the implants that were angled in the same direction as the line of force were the most stable and had the highest force at failure (253 + or - 74.05 N; P <0.001). The implants angled away from the direction of force were the least stable and had the lowest force (87 + or - 27.2 N) at failure.
The more closely the long axis of the implant approximates the line of applied force, the greater the stability of the implant and the greater its resistance to failure.
本研究旨在确定迷你种植体植入方向对种植体-骨界面抗破坏能力的影响。
将迷你种植体（IMTEC，俄克拉荷马州阿德莫尔）置于 9 个人体下颌骨中，以 90 度或 45 度角植入骨表面，并进行拉力（拉伸）和剪切测试以确定其失效情况。施力线和 45 度角植入的方向与骨刚度的最大轴平行或垂直。在剪切测试中，以 45 度角植入的种植体向并与剪切力的轴成一定角度。
所有组中，以 90 度角植入的种植体在失效时的力最大（342+/-80.9 N；P<0.001）。在剪切测试中，与力线方向相同的种植体角度最稳定，失效时的力最大（253+/-74.05 N；P<0.001）。偏离力方向的种植体角度最不稳定，失效时的力最小（87+/-27.2 N）。
种植体的长轴越接近施力线，种植体的稳定性就越高，抗破坏能力就越强。
