Background and aims. The aim of this study was to assess the opening torque of grooved and non-grooved screws made of shape memory alloys (SMA) for fixation of mandibular fractures. Materials and methods. In this in vitro study the opening torques of ten SMA screws with grooves and ten SMA screws without grooves were compared in 20 holes (10 holes for grooved screws and 10 holes for non-grooved screws) placed in the bovine mandible. Statistical significance was set at P < 0.05. Results. The mean opening torque was 2.27 ± 0.43 nm for screws in the control group and 2.05 ± 0.45 nm for screws in the grooved group (P < 0.05, P = 0.08). Conclusion. This study revealed that the torque needed for opening the grooved screws was higher in comparison with current fixation screws; however, the difference was not statistically significant.