<prompt> Frequency of ultrasonic preparation is:20,000 - 25000 cycles sec5000 - 15000 cycles sec30000 - 40000 cycles sec1500 - 6500 cycles sec  <response>: Ultrasonic preparation: Consists of a peeso electric ceramic unit that generates ultrasonic waves which activate a magnetostrictive hand piece.The hand piece produces movements of the shaft of the file between 0.001 to 0.004 inches in a frequency of 20,000 25,000 sec.NaOCI is used as irrigant solution.Increased thermal and mechanical ability of the irrigating solution removes debris and tissue effectively and removal of smear layer is also efficient. 