Boyle J M, Frost D E, Foley W L, Grady J J
Department of Oral and Maxillofacial Surgery, School of Dentistry, University of North Carolina.
Int J Adult Orthodon Orthognath Surg. 1993;8(2):129-33.
This study investigates the retentive capacity of 2.0-mm self-tapping screws in porcine rib utilizing axial pull-out tests as well as torque measurements of insertion and stripping. These techniques have been performed independently; this analysis assesses the association between pull-out and torque values. The Goodman-Kruskel correlation coefficient between pull-out and insertional torque is 0.13, while the correlation between pull-out and stripping torque is 0.21. Partial correlation indexes control the thickness of bone, a confounding factor. Nonparametric analysis of covariance showed no significant difference between insertion of screws and pull-out of the screws, but stripping versus pull-out test was significant. Given these findings, it appears that insertional torque may be used as an alternative technique for screw retention analysis. Because insertional torque tests can be conducted in the operating room, results of clinical studies can be compared to laboratory analyses.
本研究利用轴向拔出试验以及插入和拧出扭矩测量，调查了2.0毫米自攻螺钉在猪肋骨中的固位能力。这些技术是独立进行的；本分析评估了拔出力与扭矩值之间的关联。拔出力与插入扭矩之间的古德曼-克鲁斯卡尔相关系数为0.13，而拔出力与拧出扭矩之间的相关系数为0.21。偏相关指数控制了骨厚度这一混杂因素。非参数协方差分析表明，螺钉的插入与拔出之间无显著差异，但拧出与拔出试验有显著差异。基于这些发现，插入扭矩似乎可作为螺钉固位分析的替代技术。由于插入扭矩测试可在手术室进行，因此临床研究结果可与实验室分析结果进行比较。
