Ultrasonic scalers use piezoelectric or magnetostrictive technology to produce high-frequency vibrations that remove deposits from tooth surfaces. Piezoelectric scalers generate vibrations when crystals placed under mechanical stress produce electrical charges, while magnetostrictive scalers use an electromagnetic field to change the dimensions of metal stacks. These vibrations occur at 24,000-50,000 cycles per second. Cavitation produced by the vibrations disrupts bacterial cell walls and aids in removing pathogens from teeth.