Comparison of the maximum hand-generated torque by professors and postgraduate dental students for tightening the abutment screws of dental implants

Background. Dental implants are utilized with an ever-increasing rate. One of the causes of abutment screw loosening has been identified as inadequate preload. The objective behind this study was to compare the maximum hand-generated torque for tightening abutment screws by professors and postgraduate dental students using a digital torquemeter with 0.1 N/cm precision. Methods. In a laboratory study conducted in Dental Implant Department of Faculty of Dentistry, Tabriz University of Medical Sciences, the maximum hand-generated torque for tightening abutment screws by professors and postgraduate dental students was investigated, using a digital torquemeter with 0.1 N/cm precision. Results. The participants consisted of 36 (41.9%) females and 50 (58.1%) males, totaling 86 participants, of whom 45 (46.87%) and 41 (53.13%) were university professors and postgraduate dental students, respectively. The mean age of the participants was 33.4±10.2 years with an age range of 25‒60 years; 50 (58.1%) participants were in the 25‒34-year, 23 (26.7%) in the 35‒47-year, and 13 (15.1%) in the 48‒60-year age range. The mean age of professors and postgraduate dental students was 41±8.3 and 25.1±3.3 years, respectively. The means of maximum torques generated by female and male professors were 14.3±3 and 20.8±4.2, respectively. The means of maximum torques generated by female and male postgraduate dental students were 14.7±3.4 and 18.7±4.3, respectively. Statistical analyses showed no significant differences between the mean maximum torques generated by professors and postgraduate dental students (P=0.051). Conclusion. In the present study, the mean maximum torque generated by professors was higher than that generated by postgraduate dental students. However, the difference was not statistically significant. The mean maximum torque generated by male subjects was significantly higher. No interaction was seen between the studied groups and sex. However, there was a statistically significant difference between the mean maximum torques generated in different age ranges; i.e., the maximum torque generated in the 25‒34-year age range was lower than that in the other two age groups. Finally, the effect of age range on the mean maximum torque was similar in both groups.