Effects of repeated drill use on temperature of bone during preparation for osteosynthesis self-tapping screws

The mean (range) rise in temperature for the three drills were: new drill 7.5 °C (0.6-20.5 °C); drill after 600 holes 13.4 °C (5.7-28.3 °C); and drill from theatre 25.4 °C (12.4-41.3 °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.