Control of torque accuracy in some endodontic motors

Aim. The aim of this study was to examine and compare the accuracy of torque limitation of different torque controlled motors and contra-angles used in endodontics. Methods. The real torque was measured with Dynamic Torque Measurement of Endodontic Systems, Magtrol HD-100-8NA-4811, Sirona Dental System; this dynamic torque measurement system is connected through a special instrument to the contra-angle of the endodontic motor under evaluation. In this study six different endodontic motors were analized: ATR EndoPlus, SIROEndo_Pocket, VDW.SILVER, VDW.GOLD, ASEPTICO Endo It e MAILLEFER X-Smart. For each motor the real torque was measured to a specific speed and it was compared to the value on the motor display, which was the set value of the operator. Results. ASEPTICO Endo It with +46% showed the highest upper deviation; also MAILLEFER X-Smart, ATR EndoPlus, VDW.GOLD and SIROEndo Pocket had a high deviation with 24%, +13%, +11% and +12% respectively; VDW.SILVER achieved the best results: the values of its torque settings were within the range +3%, -18% of deviation. Conclusions. Lower values of torque produce an efficiency loss while upper values increase the fracture probability; by this study VDW.SILVER is the motor which showed the best results for lower and upper values to set torque.