Clinicians often refer to any power-driven scaler as an ultrasonic. However, the savvy clinician will know the differences in these machines and select the appropriate device for the individual patient’s needs. Both sonic and ultrasonic scalers utilize rapidly vibrating, water-cooled tips to remove de-posits from the tooth surface and to debride the periodontal pocket. The vibration of the insert tip is measured as frequency. The sonic scaler operates in a frequency range of 2,500 to 7,000 cycles per second.
A sonic unit attaches to conventional high-speed handpiece tubing. The unit is small and portable since a separate power unit is not needed. Compressed air blows over a metal rod in the unit, which pulsates and causes the tip to vibrate in an orbital pattern. Water flows through the unit to dissipate heat that builds up from the pulsating rod. As the frequency range of the sonic scaler is extremely low, it is difficult to remove tenacious deposits with this type scaler.
Ultrasonic units operate between 20,000 and 50,000 cycles per second. The 2 types of ultrasonic scaler units currently on the market are the piezoelectric and the magnetostrictive. These units have been shown to be effective in deposit removal and, with their variety of tip-styles, are excellent devices for nonsurgical periodontal therapy.
The dental handpiece of piezoelectric devices contains ceramic crystals which change size as electrical current is passed over them. This size change results in a linear motion of the unit’s tip. Although water flows through the unit, little heat is produced by the movement of the crystals or tip.
The magnetostrictive ultrasonic unit functions at a frequency just slightly lower than the piezoelectric model. This scaler’s handpiece contains a stack of metal strips or a metal rod which shortens and lengthens when exposed to an electromagnetic field. This shortening/lengthening process causes an elliptical movement of the tip. Heat is generated by the electrical-to-mechanical energy shift; therefore, water-cooling is necessary. Water flows through the handpiece, providing the needed cooling plus the added benefit of lavage, or flushing of the periodontal pocket.
High Speed Imaging of Cavitation around Ultrasonic Scaler
Comparison of magnetostrictive and piezoelectric ultrasonic scaler