Ultrasonic dissection uses what mechanism?

• A. Electrical current directly cutting tissue
• B. Mechanical energy converted to high frequency ultrasonic vibration
• C. Thermal energy from laser
• D. Chemical reaction at blade tip

Answer: (B)

Ultrasonic dissection relies on mechanical energy converted to high‑frequency vibration delivered to the tissue by the instrument’s blade. A transducer inside the device turns electrical energy into ultrasonic motion, causing the blade to oscillate rapidly. This rapid, localized vibration mechanically disrupts tissue and allows precise cutting along tissue planes; the energy is mainly mechanical, not electrical conduction through the tissue, and not from laser or chemical reactions. The heat generated from this vibration assists some coagulation by protein denaturation at the tip, but the fundamental mechanism is the high‑frequency mechanical disruption rather than electrical cutting, laser energy, or a chemical reaction.