Florvaag Britta, Kneuertz Peter, Lazar Frank, Koebke Jürgen, Zöller Joachim E, Braumann Bert, Mischkowski Robert A
Department of Orthodontics, University of Cologne, Cologne, Germany.
J Orofac Orthop. 2010 Jan;71(1):53-67. doi: 10.1007/s00056-010-9933-y. Epub 2010 Feb 5.
Comparing five commercially-available miniscrew types for skeletal anchorage with regard to the biomechanical properties influencing their primary stability.
Included in this study was a total of 196 self-tapping and self-drilling miniscrews having a diameter of 2 mm (or the largest possible diameter of the manufacturer in question), a thread shaft length of 10 mm, or the longest miniscrew supplied by the manufacturers. The screw types tested were the FAMI 2, Orlus mini-implant, T.I.T.A.N. Pin, tomas-pin and Vector TAS. Insertion and loosening torque measurements, and pullout tests in axial (0 degrees), 20 degrees and 40 degrees directions, as well as test series with and without pilot hole drilling were performed. Bovine femoral heads having the same bone mineral density (BMD) were used as bone-testing material.
Higher insertion torques were found for the cylindrical FAMI 2 screw, the conical Orlus mini-implant and the Vector TAS screw (with mean values of 39.2 Ncm, 32.1 Ncm and 49.5 Ncm) than for the cylindrical T.I.T.A.N. pin and tomas-pin. Insertion without predrilling led the insertion torques of all five screws to rise significantly. We noted statistically significant differences among the five screws in the pullout tests. Those highly significant differences at axial (0 degrees) and 20 degrees angles were not apparent at the 40 degrees pullout angle. Compared with the pullout forces (load) in the axial direction, the cylindrical screws' load values decreased markedly according to the angle (by up to -46.6%). The reduction in pullout force in conjunction with an increasing angle was much less pronounced in the conical screws (-0.8% to -29.0%). The tomas-pin demonstrated the highest pullout force and stiffness values throughout the tests. A total of five tomas-pins, two Orlus mini-implants and one FAMI 2 screw fractured during the pullout tests.
Results from our insertion torque measurements suggest that a conical screw design will provide greater primary stability than cylindrical screw types. The cylindrical screw design's superiority was evident in the pullout tests. All the miniscrews' primary stability rose after drill-free insertion. The tomas-pin screws, although biomechanically superior to the other screws, were most prone to fracture.
比较五种市售微型螺钉在骨骼锚固方面影响其初始稳定性的生物力学性能。
本研究共纳入196颗自攻自钻微型螺钉，直径为2mm（或相关制造商提供的最大直径），螺纹轴长度为10mm，或为制造商提供的最长微型螺钉。测试的螺钉类型有FAMI 2、Orlus微型种植体、T.I.T.A.N. Pin、tomas-pin和Vector TAS。进行了插入和松动扭矩测量，以及在轴向（0度）、20度和40度方向的拔出试验，还进行了有和没有预钻孔的测试系列。使用具有相同骨密度（BMD）的牛股骨头作为骨测试材料。
圆柱形的FAMI 2螺钉、锥形的Orlus微型种植体和Vector TAS螺钉的插入扭矩较高（平均值分别为39.2Ncm、32.1Ncm和49.5Ncm），高于圆柱形的T.I.T.A.N. Pin和tomas-pin。不进行预钻孔插入会使所有五种螺钉的插入扭矩显著增加。在拔出试验中，我们注意到五种螺钉之间存在统计学上的显著差异。在轴向（0度）和20度角度的那些高度显著差异在40度拔出角度时并不明显。与轴向拔出力（载荷）相比，圆柱形螺钉的载荷值根据角度显著降低（降幅高达-46.6%）。锥形螺钉在拔出力随角度增加时的降低程度要小得多（-0.8%至-29.0%）。在整个测试过程中，tomas-pin表现出最高的拔出力和刚度值。在拔出试验中，共有5颗tomas-pin、2颗Orlus微型种植体和1颗FAMI 2螺钉发生断裂。
我们的插入扭矩测量结果表明，锥形螺钉设计比圆柱形螺钉类型能提供更大的初始稳定性。圆柱形螺钉设计在拔出试验中的优势明显。所有微型螺钉在无钻孔插入后的初始稳定性都有所提高。tomas-pin螺钉虽然在生物力学上优于其他螺钉，但最容易发生断裂。
