Allan W, Williams E D, Kerawala C J
Regional Medical Physics Department, Sunderland Royal Hospital, Kayll Road, Sunderland SR47TP, UK.
Br J Oral Maxillofac Surg. 2005 Aug;43(4):314-9. doi: 10.1016/j.bjoms.2004.11.007.
Drills used during preparation for osteosynthesis with self-tapping screws are often used repeatedly until they become blunt and ineffective. Because the sharpness of the drill is one of the most important factors in its cutting efficiency, blunt drills may require the application of extra force, which in turn may contribute to excessive frictional heat produced during preparation of screw holes. Large rises in temperature can impair bony regeneration around screws and contribute to failure of internal fixation. In an attempt to quantify the potential increase in temperature produced by blunt drills, we devised an in vitro experiment to simulate preparation for osteosynthesis by using drills with different degrees of wear. Three drills were used: one was new, one had drilled 600 holes, and the third drill had been in use in theatre for several months. The mean (range) rise in temperature for the three drills were: new drill 7.5 degrees C (0.6-20.5 degrees C); drill after 600 holes 13.4 degrees C (5.7-28.3 degrees C); and drill from theatre 25.4 degrees C (12.4-41.3 degrees C). There was a highly significant difference in the temperatures generated by the three drills, and the changes in temperature were related to the amount of wear. The cost of drills is low, and as their repeated use can compromise the results of the operation they must be discarded after single use.
在使用自攻螺钉进行骨合成准备过程中使用的钻头，常常会被反复使用，直到它们变钝且失效。由于钻头的锋利度是其切削效率的最重要因素之一，钝钻头可能需要施加额外的力，这反过来可能会导致在准备螺孔过程中产生过多的摩擦热。温度大幅升高会损害螺钉周围的骨再生，并导致内固定失败。为了量化钝钻头可能产生的温度升高，我们设计了一项体外实验，通过使用不同磨损程度的钻头来模拟骨合成准备过程。使用了三种钻头：一种是新的，一种钻了600个孔，第三种钻头在手术室中使用了几个月。三种钻头的平均（范围）温度升高分别为：新钻头7.5摄氏度（0.6 - 20.5摄氏度）；钻600个孔后的钻头13.4摄氏度（5.7 - 28.3摄氏度）；以及手术室中的钻头25.4摄氏度（12.4 - 41.3摄氏度）。三种钻头产生的温度存在极显著差异，且温度变化与磨损量有关。钻头成本较低，但其反复使用会影响手术结果，因此必须一次性使用后丢弃。
