Effects of screw and host factors on insertion torque and pullout strength
Effects of screw and host factors on insertion torque and pullout strength
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DOI：
10.2319/070111-427.1
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发表时间：
2012-07-01
影响因子：
3.4
通讯作者：
Buschang, Peter H.
中科院分区：
文献类型：
--
作者：
Shah, Ankit H.;Behrents, Rolf G.;Buschang, Peter H.
目的：通过实验研究改变种植体长度、外径、皮质骨厚度和皮质骨密度对微型正畸种植体（msi）初级稳定性的影响。材料与方法：在不同皮质密度（0.64 g/cc或0.55 g/cc）和皮质厚度（1 mm或2 mm）的合成骨中测量216颗msi的最大插入扭矩（IT）和拔出强度（POS）。评估3个msi：长6mm /1.75 mm外径，长3mm /1.75 mm外径，长3mm /2.0 mm外径。为了测试POS，以5毫米/分钟的速度施加垂直力，直到发生失效。结果：6mm msi的IT和POS明显高于3mm msi （P < 0.001）。外径为2.0 mm的3mm msi的IT和POS均显著高于外径为1.75 mm的3mm msi （P < 0.001）。植入较厚、较密皮质骨的msi的IT和POS显著（P < 0.001）增加。结论：msi的外径和长度均影响其稳定性。皮质骨厚度和皮质骨密度的增加增加了msi的初级稳定性。（直角正交，2012;82:603-610）
Objective: To experimentally study the effects of altering implant length, outer diameter, cortical bone thickness, and cortical bone density on the primary stability of orthodontic miniscrew implants (MSIs).Materials and Methods: Maximum insertion torque (IT) and pullout strength (POS) of 216 MSIs were measured in synthetic bone with different cortical densities (0.64 g/cc or 0.55 g/cc) and cortical thicknesses (1 mm or 2 mm). Three MSIs were evaluated: 6-mm long/1.75-mm outer diameter,,3-mm long/1.75-mm outer diameter, and 3-mm long/2.0-mm outer diameter. To test POS, a vertical force was applied at the rate of 5 mm/min until failure occurred.Results: The 6-mm MSIs displayed significantly (P < .001) higher IT and POS than the 3-mm MSIs did. The 3-mm MSIs with 2.0-mm outer diameters showed significantly higher (P < .001) IT and POS than the 3-mm MSIs with 1.75-mm outer diameters. The IT and POS were significantly (P < .001) greater for the MSIs placed in thicker and denser cortical bone.Conclusion: Both outer diameter and length affect the stability of MSIs. Increases in cortical bone thickness and cortical bone density increase the primary stability of the MSIs. (Angle Orthod. 2012;82:603-610.)