Bone heat generated using conventional implant drills versus piezosurgery unit during apical cortical plate perforation

Background: The apical portion of the implant osteotomy receives less irrigation and cooling during surgical preparation. High bone temperature, above the critical 10°C threshold, may impair osseointegration, particularly around dense cortical bone. The aim of this study was to evaluate the apical cortical plate temperature increase with two different devices and pressure loads in a porcine rib ex vivo model. Methods: A total of 24 implant sites were prepared on porcine ribs, divided into 4 groups of 6 samples each, according to the device used (conventional drill system or piezosurgery) and pressure load applied (1,000 g or 1,500 g). A rubber dam was used to isolate the apical cortical plate from the cooling effect of irrigation. Temperature variation measurements were taken using an infrared thermometer. Results: The piezosurgery unit was two times more likely to increase the osteotomy temperature by 10°C (OR = 2; 95% CI 1.136, 3.522; P < 0.05). The average temperature increase was 0.07°C (SD = 0.10) for group 1 (drill system 1,000 g); 0.22°C (SD = 0.26) for group 2 (drill system 1,500 g); 9.18°C (SD = 4.51) for group 3 (piezo-surgery 1,000 g); and 8.17°C (SD = 6.12) for group 4 (piezosurgery 1,500 g). The piezosurgery site preparation had significantly higher temperature increase than did the conventional drill site preparation (P < 0.05). There was no statistically significant difference in temperature change between the two pressure loads applied (P = 0.78). Temperature increases exceeded the critical 10°C threshold in half of the samples prepared with the piezoelectric device. Conclusions: Bone overheating using a piezosurgery unit is a potential risk during implant site preparation. The piezosurgical device resulted in significantly higher temperatures than did conventional drilling at the apical cortical portion of the osteotomy. The temperature increase was often higher than the critical 10°C threshold.