Effect of drill bit angle on temperature rise during mandible drilling with finite element method

Excessive temperature rise during drilling of the mandible for dental implant placement might damage adjacent osseous tissues. Various factors affect temperature rise, including the geometrical parameters of surgical drills, one of which is the drill bit head angle. The aim of this research was to determine suitable drill bit head angle to induce minimum temperature rise during mandible drilling operation for dental implant placement.

In this research, the finite element analysis software DEFORM-3D Ver 6.1 was used for mandibular cortical bone drilling. To this end, three drill bits with different head angles of 70, 90 and 118 degrees were designed in this software. Three-dimensional modeling of the mandible was performed using CT scan images and MIMICS 10.01 software. To place the drill bit on the mandibular model, CATIA V5R19 software was used to remove a tooth from the distal end of the mandibular model. Finally, to perform the drilling operation, the model of the mandible was imported to DEFORM-3D Ver 6.1 software in STL format.

At the end of these simulations, the diagrams of maximum heat generated in mandibular bone during drilling operation and mean temperatures were obtained. The results showed that the drill bit with 70° head angle resulted in the minimum mean temperature of 75.4ºC compared to 90 and 118 degrees with mean temperatures of 81.1°C and 93.4°C, respectively.

The results indicated that drill bit with 70° head angle is more appropriate for mandibular bone drilling operation than other larger bit angles.