Loss of Accuracy of Torque Wrenches Due to Clinical Use and Cleaning Procedure: Short Communication

Purpose: The aim of this study was to investigate the way intensive use and multiple cleanings of torque wrenches may interfere with accurary over time. Materials and Methods: Three different brands (one spring-style and two friction-style types) were tested at baseline and after enduring mechanical testing (1,000 cycles) and cleaning in a thermal disinfector (150 cycles). Torque wrenches were tested at a predetermined value of 30 Ncm at given intervals, and true values were registered by means of a digital torque gauge. Results: All measured values varied between 28.3 Ncm and 31.1 Ncm. Only the spring-style torque wrench revealed values that differed significantly from baseline after both mechanical testing (P .001) and cleaning (P .05). Conclusion: The spring-style torque wrench produced values that changed significantly after multiple mechanical and multiple cleaning cycles. However, the differences were small and the measured values from all tested specimens were close to the predetermined value of 30 Ncm.