Heat generation during implant placement in low-density bone: effect of surgical technique, insertion torque and implant macro design

Abstract

Objectives The study aimed to investigate the effect of surgical technique, implant macrodesign and insertion torque on bone temperature changes during implant placement. Material and methods In the in vitro study, 144 self-tapping (blueSKY (R) 4x10mm; Bredent) and 144 non-self-tapping (Standard implant (R) 4.1x10mm; Straumann) were placed in osteotomies prepared in pig ribs by lateral bone condensing or bone drilling techniques. The maximum insertion torque values of 30, 35 and 40Ncm were used. Real-time bone temperature measurement during implant placement was performed by three thermocouples positioned vertically, in tripod configuration around every osteotomy, at a distance of 5mm from it and at depths of 1, 5 and 10mm. Data were analysed using Kruskal-Wallis, Mann-Whitney U-tests and Regression analysis. Results Significant predictor of bone temperature at the osteotomy depth of 1mm was insertion torque (P=0.003) and at the depth of 10-mm implant macrodesign (P=0.029), while no significant predictor at depth of 5mm was identified (0.05). Higher insertion torque values as well as non-self-tapping implant macrodesign were related to higher temperatures. Implant placement in sites prepared by bone drilling induced significantly higher temperature increase (P=0.021) compared with bone condensing sites at the depth of 5mm, while no significant difference was recorded at other depths. Compared with 30Ncm, insertion torque values of 35 and 40Ncm produced significantly higher temperature increase (P=0.005; P=0.003, respectively) at the depth of 1mm. There was no significant difference in temperature change induced by 35 and 40Ncm, neither by implant macrodesign at all investigated depths (0.05). Conclusions Placement of self-tapping implants with low insertion torque into sites prepared by lateral bone condensing technique might be advantageous in terms of thermal effect on bone.