fem investigation of drilling conditions on heat generation during teeth implantation

The first step of implanting teeth is to drill a hole in the jaw bone. the excessive temperature produced during drilling is one of the destructive factors for bony tissue. if the temperature generation during surgical drilling exceeds the critical temperature, it could lead to osteonecrosis. this research intends to study drilling parameters such as drilling speed, feed rate, cooling condition, and tool geometry by fem method in order to achieve the most appropriate drilling conditions. three-dimensional modeling of lower jaw bone from the ct scan images is made by mimics 10.01 software. in order to place the drill bit on the mandibular model, two teeth are removed from the final part of the model by catia v5r20 software. deform-3d (version 10.2) is used for mandibular cortical bone drilling simulation. for this purpose, drill bits with different geometrical parameters including point angles of 90, 70, and 118 degrees and helix angles of 20, 23, and 30 degrees are designed in the software. the simulations are carried out using different feed rates (60, 90, 120, and 200 mm/min) and rotational speeds (200, 400, 800, and 1200 revs/min). the simulation results show that the most appropriate conditions for the lowest temperature are as follows: 70 degrees for drill bit point angle, 23 degrees for helix angle, 200 mm/min for feed rate, and 200 revs/min for rotational speed. also, by using coolant, the maximum temperature reduces by approximately 12 degrees. the results also suggest that the rotational speed of 200 revs/min and feed rate of 200 mm/min have the largest thrust force in the drilling area. the finite element results are validated by available experimental data.