Evaluation of the heat released in bones of different density during the drilling of dental implant burs by finite element analysis

Aim: In this study, it is aimed to measure the heat generated in bones of different densities during osteotomy with finite element analysis, to calculate the cooling time of the bone, to evaluate the effect of irrigations at different temperatures on the heat generated in the bone, and to observe the thermal changes occurring in the adjacent implant socket while the primary implant socket is being drilled. Materials and Methods: In order to observe the heat generated by the implant burs, cortical and cancellous models were created according to the Misch classification (D1, D2/D3 and D4) of 3 different densities of bone. Each model was drilled with burs of 3 different diameters (2.8 mm, 3.5 mm and 4.2 mm) under irrigations at 25°C and 10°C and without irrigation. After the drilling process was finished, the cooling data was observed for 180 seconds. The heat values formed in the bone and adjacent implant socket during osteotomy and the subsequent cooling data were calculated by finite element thermal stress analysis. Results: In primary implant socket osteotomies in all cortical bone models, the temperature formed in the bone did not exceed 47°C in case of irrigation. An effective temperature reduction was observed when using 10°C irrigation solution compared to 25°C irrigation. Continuing or simply waiting for irrigation after drilling lowered the bone temperature below the critical threshold. In osteotomies under irrigation, the highest cortical bone temperatures were measured in the D1 bone model, and the temperature values formed in the bone decreased as the cortical bone density decreased. Conclusion: Using cooled irrigation and continuing irrigation to cool the bone between milling is advised during implant osteotomy, especially in D1 bone. If more than one implant will be placed, it is advised to insert the implants after all implant sockets have been prepared. As a result, there will be less thermal injury to the bone. In vivo investigations are required to confirm the findings, even if our study's findings were found to be consistent with those of earlier in vivo studies.