Performance of Ultrasonic Devices for Bone Surgery and Associated Intraosseous Temperature Development

Purpose: The purpose of this study was to evaluate and to compare the bone-cutting performance and intraosseous temperature development of three modern ultrasonic devices for bone surgery (UDBS). Materials and Methods: The following UDBS and associated cutting tips (straight bone saws) were used in this study: (1) Piezosurgery II professional, tip OT 7 (Mectron); (2) Piezotome, tip BS 1 (Acteon); and (3) SurgySonic, tip ES007 (American Dental Systems/Günther Jerney). In the experimental setup UDBS, handpieces were immobilized, and bone specimens from the middiaphysis of a bovine femur were moved in a longitudinal direction under the cutting tip to a standardized depth of 3.0 mm. Intraosseous temperature development was measured using a glass-fiber isolated thermocouple. The cutting performance was defined by the time required to reach the cutting depth of 3.0 mm. Statistical analysis was performed using the Wilcoxon rank sum test. Results: The median increase (25th through 75th percentiles) of the local intraosseous temperature was 3.0°C (2.2°C to 4.2°C) for the SurgySonic, 2.2°C (1.8°C to 3.2°C) for the Piezosurgery II, and 1.1°C (0.7°C to 1.6°C) for the Piezotome. The median cutting performance was 0.31 mm/s (0.11 to 0.46 mm/s) for the Piezotome, 0.25 mm/s (0.23 to 0.27 mm/s) for the Piezosurgery II, and 0.04 mm/s (0.03 to 0.05 mm/s) for the SurgySonic. Conclusions: Among the three tested UDBS, the Piezotome and the Piezosurgery II showed a significantly higher cutting performance than the SurgySonic. The Piezotome produced the smallest increase in intraosseous temperature. Keywords: cutting performance, intraosseous temperature development, material testing, ultrasonic bone surgery