Heat production during different ultrasonic and conventional osteotomy preparations for dental implants

Objectives: The purpose of this study was to evaluate the intraosseous temperature changes during ultrasonic and conventional implant site preparation in vitro with respect to the effect of load and irrigation volume. Material and methods: Implant sites were prepared using two different ultrasonic devices (Piezosurgery, Mectron Medical Technology and VarioSurg, NSK) and one conventional device (Straumann) at loads of 5, 8, 15 and 20N and with irrigation volumes of 20, 50 and 80 ml/min. During implant site preparation, temperatures were measured in fresh, equally tempered bovine ribs using two thermocouples placed at a distance of 1.5mm around the drilling site in cortical and cancellous bone. The preparation time was recorded. Results: The heat production and time required for implant site preparation using both ultrasonic devices were significantly higher than those for conventional drilling (P<0.01). Increased loading had no effect on heat production. A higher irrigation volume was associated with a diminished temperature increase in the cortical bone for ultrasonic but not for conventional drilling, which resulted in significantly lower temperatures in cortical as compared with cancellous bone during ultrasonic implant site preparation. Conclusions: Ultrasonic implant site preparation is more time consuming and generates higher bone temperatures than conventional drilling. However, with the levels of irrigation, ultrasonic implant site preparation can be an equally safe method.