Torque value of two different dental implant torque wrenches after 2000-time usage: an in vitro comparative study

Abstract

The purpose of this study was to investigate the accuracy of universal-use spring-style torque wrenches and adjustable toggle torque wrenches. Two commonly used torque wrenches (spring type and adjustable toggle type) have been included in the study. Three new spring wrenches and three new adjustable toggle wrenches were measured their peak torque outputs regarding to the using order from 1st to 2000th application. All wrenches were indicated to generate 30 Ncm while tested. The data obtained was calculated for the accuracy using student’s t-test. The correlation between torque outputs and using times was analyzed using Pearson’s correlation coefficient test. At the target torque 30 Ncm, means torque output of spring type and toggle type were 31.3133±0.37554 Ncm and 32.6533±1.37863 Ncm respectively. There was no significant difference between torque values of both types (ρ=0.180). Within 2000 torque applications, means of spring type and toggle type were found to deviate from the target torque 4.38% (ρ<0.05) and 8.85% (ρ>0.05) respectively. Conclusions: Within the limitation of the study, it may be concluded that after 2000 times of usage, the two mostly used torque wrench types in dental implant treatment provide ±10% accurate torque value to tighten the abutment screw.