Purpose: To establish a method for measuring the heat generated when preparing an osteotomy site, and to assess for correlations of rotational speed, proceeding speed, loading value of the drill (contact pressure), motion pattern, and bone density with temperature increases. Materials and Methods: A thermocouple was placed in the internal irrigation hole of a 2.0-mm-diameter twist drill used for measuring osteotomy site temperature. In the artificial blocks, two different densities were used to drill under varying conditions including drill proceeding, rotating speed, and motion pattern. The drilling procedure was repeated five times for each combination, and the data collected were statistically analyzed using multiple regression analysis. Results: Strong positive correlations were found among bone density, drill motion pattern, and maximum temperature, and a positive correlation was found in proceeding speed (P .001). Rotation speed and maximum temperature were not correlated (P .001). Conversely, loading values of the drill increased with the lower rotation speed and higher proceeding speed, which were effective in controlling the temperature rise. Conclusion: When preparing a simulated bone for an osteotomy with a thermocouple inserted into a twist drill with internal irrigation, the drilling motion pattern, bone density, drill speed, and proceeding rate affected bone temperature, in descending order. It was also observed that bone temperature correlated positively with speed and negatively with proceeding speed, independent of density. This indicates that lower drill speed and higher proceeding speed without excessive loading values minimize the bone temperature heat. Keywords: heat generated, methods for measuring, socket preparation