In the last decade, the use of surgical guides in dentistry has expanded to include endodontic surgery, yet most studies have focused on accuracy rather than potential heat generation. This in vitro study evaluated heat generation during bone drilling with custom-made bone trephines, both with and without static surgical guides, and compared the results to those of 2 mm pilot drills. Drilling was performed on porcine rib bone specimens under controlled conditions, with heat generation measured using an infrared thermometer. None of the groups exceeded the critical temperature of 47 °C; although, the guided trephine group recorded the highest peak temperature (7.9 °C above baseline). Significant differences in heat increments were observed among the groups. Post hoc analyses revealed that the guided pilot drill produced significantly lower heat increments compared to the trephine groups, particularly during the penetration of the second cortical layer and at peak temperatures (p < 0.05). The use of a surgical guide did not limit the cooling and lubricating effects of irrigation in the trephine groups. Regression analyses confirmed a strong relationship between drilling time and temperature increase, with guided trephines showing a steeper temperature rise compared to pilot drills. These findings emphasize the importance of proper irrigation, sharp instruments, reduced drilling speeds, and careful technique to minimize heat generation during guided bone drilling procedures.