Semper W, Kraft S, Krüger T, Nelson K
Dept. of Oral and Maxillofacial Surgery, Clinical Navigation and Robotics, Charité-Campus Virchow Clinic, Augustenburger Platz 1, 13353 Berlin, Germany.
J Dent Res. 2009 Aug;88(8):731-5. doi: 10.1177/0022034509341243.
Rotational freedom of the implant-abutment connection influences its screw joint stability; for optimization, influential factors need to be evaluated based on a previously developed closed formula. The underlying hypothesis is that the manufacturing tolerances, geometric pattern, and dimensions of the index do not influence positional stability. We used the dimensions of 5 commonly used implant systems with a clearance of 20 microm to calculate the extent of rotational freedom; a 3D simulation (SolidWorks) validated the analytical findings. Polygonal positional indices showed the highest degrees of rotational freedom. The polygonal profile displayed higher positional stability than the polygons, but less positional accuracy than the cam-groove connection. Features of a maximal rotation-safe positional index were determined. The analytical calculation of rotational freedom of implant positional indices is possible. Rotational freedom is dependent on the geometric design of the index and may be decreased by incorporating specific aspects into the positional index design.
种植体-基台连接的旋转自由度会影响其螺钉连接稳定性；为了进行优化，需要基于先前推导的封闭公式对影响因素进行评估。潜在的假设是索引的制造公差、几何图案和尺寸不会影响位置稳定性。我们使用了5种常用种植体系统的尺寸，间隙为20微米，来计算旋转自由度的程度；三维模拟（SolidWorks）验证了分析结果。多边形位置索引显示出最高程度的旋转自由度。多边形轮廓显示出比多边形更高的位置稳定性，但位置精度低于凸轮-凹槽连接。确定了最大旋转安全位置索引的特征。种植体位置索引旋转自由度的分析计算是可行的。旋转自由度取决于索引的几何设计，并且可以通过将特定方面纳入位置索引设计来降低。
