Intraosseous heat generation during sonic, ultrasonic and conventional osteotomy.

Abstract Objectives To assess heat generation in osteotomies during application of sonic and ultrasonic saws compared to conventional bur. Methods Two glass-fiber isolated nickel–chromium thermocouples, connected to a recording device, were inserted into fresh bovine rib bone blocks and kept in 20 ± 0.5 °C water at determined depths of 1.5 mm (cortical layer) and 7 mm (cancellous layer) and 1.0 mm away from the planned osteotomy site. Handpieces, angulated 24–32°, were mounted in a vertical drill stand, and standardized weights were attached to their tops to exert loads of 5, 8, 15 and 20 N. Irrigation volumes of 20, 50 and 80 ml/min were used for each load. Ten repetitions were conducted using new tips each time for each test condition. The Mann–Whitney-U test was used for statistical analysis ( p Results Both ultrasonic and sonic osteotomies were associated with significantly lower heat generation than conventional osteotomy ( p Conclusion Although none of the systems under the conditions of the present study resulted in critical heat generation, the application of ultrasonic and sonic osteotomy systems was associated with lower heat generation compared to the conventional saw osteotomy. Copious irrigation seems to play a critical role in preventing heat generation in the osteotomy site.