When Should We Change Drill Bits? A Mechanical Comparison of New, Reprocessed, and Damaged Bits

Objectives: We assessed how reprocessed and damaged drill bits perform relative-to-new drill bits in terms of drilling force required, heat generated at near and far cortices, and number of usable passes. Methods: Nine pairs of nonosteoporotic human cadaveric femora were tested using 3 types of 3.2-mm drill bits (new, reprocessed, and damaged) in 3 investigations (force, temperature, and multiple usable passes). Operating room conditions were simulated. Force and temperature data were collected for each type. The multiple pass investigation measured only force. Results: New and reprocessed drill bits performed similarly regarding force required and heat generated; both outperformed damaged bits. New and reprocessed bits had a similar number of usable passes in ideal conditions. Damaged bits required nearly 2.6 times as much force to maintain drilling rate. Conclusions: Reprocessed drill bits seem to be a viable alternative to new drill bits for fracture treatment surgery in terms of force required, heat generated, and number of usable passes. Drill bits that are damaged intraoperatively should be replaced. In ideal conditions, new and reprocessed drill bits can be used for multiple consecutive cases. Clinical Relevance: Reprocessed drill bits may be as effective as new drill bits, representing potential cost savings for institutions. Both types can be considered for reuse.