Ultrasonic scalers vibrate at a frequency to help with removing stain, plaque and calculus. In addition, ultrasonic scalers create tiny air bubbles through a process known as cavitation. These bubbles serve an important function for periodontal cleanings. Since the bacteria living in periodontically involved pockets are anaerobic, meaning unable to survive in the presence of oxygen, these bubbles help to destroy them. The oxygen helps to break down bacterial cell membranes and causes them to lyse, or explode. Hand instruments may be used to complete the fine hand scaling that removes anything the ultrasonic scaler left behind. Alternatively, power scalers may be used following hand scaling in order to dispel deposits that have been removed from the tooth or root structure, but remain within the periodontal pocket.


Two ultrasonic instruments.
Sonic and ultrasonic scalers are powered by a system that causes the tip to vibrate. Ultrasonic scalers are typically powered by an air-driven turbine. Ultrasonic scalers typically use either magnetostrictive or piezoelectric systems to create vibration. Magnetostrictive scalers use a stack of metal plates bonded to the tool tip. The stack is induced to vibrate by an external coil connected to an AC source. Ultrasonic scalers also include a liquid output or lavage, which aids in cooling the tool during use, as well as rinsing all the unwanted materials from the teeth and gum line. The lavage can also be used to deliver antimicrobial agents.