Hydrodynamic ultrasonic sinus floor elevation--an experimental study in sheep.

PURPOSE: The aim of the present study was to evaluate the pressure forces appearing to elevate the sinus membrane by comparing the hydraulic and pneumatic pressure. Also, the relation between the time and volume of the applied liquid and the achieved lift-volume were determined. MATERIALS AND METHODS: A total of 190 fresh, half sheep heads were used for the present investigation. An ultrasound surgical device (Piezotome; Acteon, Bordeaux, France) was tested to evaluate the pressure increase at different flow rates. The elevation volume at different flow rates and activation times of the ultrasound hand piece were measured. RESULTS: To detach the sinus membrane pneumatically from the sinus floor, a mean average pressure of 29.54 millibars was required. Using the hydraulic technique, a mean average pressure of 19.8 millibars was determined. Comparing the different flow rates, the elevated volume increased to 0.52 mL when a flow of 60 mL/minute was used. Using an activation time of 20 seconds, a lifted volume of 3.92 mL could be measured on average. If the flow was set to a maximum of 60 mL/minute, the created volume increased to 5.58 mL. A comparison using the chi(2) test showed a significant correlation (P = .03) between the application time and the created sinus lift volume. Even at high flow rates of 60 mL/minute of the activated Piezotome for a 20-second period, no rupture of the sinus membrane of the sheep heads occurred in 190 experiments. CONCLUSION: From these results, we have concluded that hydrodynamic ultrasound could be used as an alternative method for sinus floor elevations of any size and volume with a mere 3-mm-diameter transcrestal approach, if findings from clinical investigations confirm the results of the present animal study.