The use of pilot drills in sequential drilling of the osteotomy sites: is it really necessary?

Abstract

Purpose: This study investigated the effectiveness of multi-step drill for heat production during preparation of implant sites. Materials and methods: 4 drilling experiments were carried out in this study. 2 experiments were conducted in conventional drilling sequence for the implant site of Ø4.3 and Ø4.6. And other 2 experiments were conducted in experimental drilling sequence for the implant site of Ø4.3 and Ø4.6. Conventional triflute drill and pilot drill were used in conventional drilling sequence and multi-step drill was used in experimental drilling sequence. 6 points of bovine femur were selected to measure the temperature during implant drilling. Temperature changes were assessed with infrared thermal-vision camera in real time. Each drilling sequence was performed 20 times. Thermal image data of experiment was transmitted to and analyzed by personal computer. Results: Mean value of maximum temperature during experimental drilling sequence was 44.1℃ in Ø4.3 and 45.65℃ in Ø4.6. There were no significant differences of temperature elevation between conventional and experimental drilling sequence in the critical drilling step(p<0.05). Outer part of the bone showed the highest temperature elevation during drilling. Discussion and Conclusion: Within the limitations of this study, multi-step drill was used to shorten drilling sequence by omitting the pilot drilling step. In reference to the earlier results, two conclusions made. (1) There were no significant temperature differences between conventional and experimental drilling sequence. Mean maximum temperature during experimental sequence was below 47℃. That means several steps of the drilling can be shortened by using multi-step drill. (2) Multi-step drill will be very powerful and efficient tool that gives a lot of benefits. If we shorten the procedures of implant drilling by changing the shapes of fore-end of the drills, it will be more beneficial to not only clinicians but also patients.