Ultrasonic Scalers: Piezo vs. Magnetostrictive

Ultrasonic scalers are great labor-saving devices which many find indispensable. Having an electronic instrument that vibrates 25,000 times (or more) every second can be extremely useful and can be an effective way of providing treatment in a variety of procedures.

But what to choose? There are piezo ultrasonic units, magnetostrictive and even sonic scalers that connect to your unit like a standard handpiece. All of these units use mechanical means to create vibrations but they all do it in different ways.

Sonic Scaler

First,  the handpiece scaler. More properly these are referred to as sonic scalers (rather than ultrasonic) as they normally operate at only 6 kHz. Given the lower frequency, they are less powerful than ultrasonic units.

Also known as air scalers, these scalers use a metal cylinder (rotor) balanced between o’rings to provide vibration when air pressure is applied. These attach to a standard handpiece coupler on your delivery system and operate at normal handpiece drive air pressure (32-35 psi).

Magnetostrictive Scaler

Next, magnetostrictive ultrasonic units.  Magnetostrictive scalers have metal stacks that vibrate and provide an elliptical motion of the tip. These scalers are usually considered easier to use (less technique sensitive) but are sometimes considered as less gentle.

These units are now offered in 25 kHz or 30 kHz frequencies. This technology has been around for a long time and historically, the magnetostrictive has been the most popular ultrasonic design in the United States

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Piezo Scaler

The newest introduction to the US market is the piezo ultrasonic units. Piezo’s have been around for a long time but have been predominately used in Europe.

Piezo ultrasonics have ceramic stacks that provide linear motion and generally operate at a frequency of about 32-35 kHz.

Piezo’s are more technique sensitive given the linear motion of the tips. One must use the scaler parallel to the tooth surface to avoid “hammering” with the piezo tip. When used properly, many consider the piezo to be more gentle than magnetostrictive scalers.

Piezo Scalers generally have a wider range of tips and are becoming quite popular with dentists for endodontics and some surgical procedures in addition to perio and the more commonly expected hygiene procedures.