Tightening torque of implant abutment using hand drivers against torque wrench and its effect on the internal surface of implant

AIM: The aim of this study was to compare the torque rendered by a handheld driver and a torque wrench and thereby evaluate its effect on the internal threads of implant. SETTING AND DESIGN: An in-vitro comparison of implant abutment torque using a digital torque gauge. MATERIALS AND METHODS: Thirty participants were randomly selected and were asked to torque two samples of mounted abutment analogs, one using a handheld driver and other with a torque wrench. The hex was then attached to the digital torque gauge to record the amount of torque generated and the recorded values were compared. Simultaneously, impressions of the internal threads of implant were taken using light body putty material before and after torque application. The samples were viewed under a stereomicroscope and the measurement of the initial four threads was compared. STATISTICAL ANALYSIS USED: The data was subjected to statistical analysis using SPSS version 20.0 software. The intergroup comparison was done using one sample t-test, and the internal threads were analyzed using ANOVA statistical analysis. RESULTS: The results obtained showed that the torque generated using a handheld driver was higher (27–43 Ncm) than that of torque wrench (28–35 Ncm). Torque wrench values were within the manufacturer's recommendation. The mean of internal thread changes of the handheld driver and torque wrench was 861.033 mm and 864.350 mm, respectively, showing an insignificant difference. One-way ANOVA test showed P < 0.01 and difference of 11 mm for posttreatment hand torque and 14 mm for posttreatment torque wrench values. CONCLUSIONS: The mechanical torque instrument showed specified torque values as recommended by the manufacturer. Consequently, the internal threads of the implants did not undergo any significant change using hand tightening or using a torque wrench.