title: Accuracy of dental torque wrenches.
abstract: The aim of this in vitro study was to compare the actual torque of 2 manual wrench systems to their stated (target) torque. New spring- (Nobel Biocare USA, LLC) and friction-style (Zimmer Dental, Inc.) manual dental torque wrenches, as well as spring torque wrenches that had undergone sterilization and clinical use, were tested. A calibrated torque gauge was used to compare actual torque to target torque values of 15 and 35 N/cm. Data were statistically analyzed via mixed-effects regression model with Bonferroni correction. At a target torque of 15 N/cm, the mean torque of new spring wrenches (13.97 N/cm; SE, 0.07 N/cm) was significantly different from that of used spring wrenches (14.94 N/cm; SE, 0.06 N/cm; P < 0.0001). However, the mean torques of new spring and new friction wrenches (14.10 N/cm; SE, 0.07 N/cm; P = 0.21) were not significantly different. For torque measurements calibrated at 35 N/cm, the mean torque of new spring wrenches (35.29 N/cm; SE, 0.10 N/cm) was significantly different (P < 0.0001) from the means of new friction wrenches (36.20 N/cm; SE, 0.08 N/cm) and used spring wrenches (36.45 N/cm; SE, 0.08 N/cm). Discrepancies in torque could impact the clinical success of screw-retained dental implants. It is recommended that torque wrenches be checked regularly to ensure that they are performing to target values.
authors.forename: James S
authors.initials: JS
authors.lastname: Wood
authors.forename: Nicole M
authors.initials: NM
authors.lastname: Marlow
authors.forename: Monica J
authors.initials: MJ
authors.lastname: Cayouette
mesh_terms: D003758:Dental Implantation, Endosseous / Q000295:instrumentation*; D015921:Dental Implants / Q000592:standards; D003762:Dental Instruments / Q000592:standards*; D003799:Dental Stress Analysis / Q000379:methods; D006801:Humans; D019415:Torque
chemical_list: D015921:Dental Implants
keywords: dental implant; torque; torque wrench