Root Morphology and Instrumentation Implications Practice Test

Power control in an ultrasonic unit is about changing how far the tip vibrates—the amplitude of the oscillation. When you increase this amplitude, the tip moves more each cycle, delivering more mechanical energy to the target and effectively increasing the energy (power) applied during scaling. Frequency, which is the rate of vibration, is set by the transducer and remains essentially fixed for a given device, so it isn’t what you adjust when you’re changing power. Wavelength depends on the frequency and the medium and isn’t directly adjustable with the power control. The electrical drive voltage underlies the motion, but in practice the control labeled as power corresponds to adjusting the vibration’s amplitude. So, increasing power equates to increasing the amplitude of the tip’s vibration.