Ultrasonic scalers

Power scaling devices are either ‘sonic’, vibrating between 3,000 and 8,000 times per second, or ‘ultrasonic’, operating between 20,000 and 50,000 Hz. The ultrasonic ones tend to work better than the sonic kind, deplaquing and flushing the periodontal pocket well, and destroying bacterial cell walls with cavitating bubbles in their water streams.

Ultrasonic scalers are either ‘magnetostrictive’, where energy is converted to elliptical strokes in the unit's metal rod, or ‘piezoelectric’, where strokes go in a linear pattern, back and forth, regulated by crystals in the ceramic handpiece. These both work well in calculus and stain removal, and they both have a variety of inserts for things like heavy deposits or root planing.

We stock every variety of descalers here at Sky Dental, and we invite you to browse and ask questions.

But let’s talk about the two kinds of ultrasonics. Which is better?

Magnetoscriptive tips, which are pretty convenient for you at chairside (easy to work with and handily interchangable among manufacturers), are a little buzzy and uncomfortable for some patients, particularly if you use the distal end of the tip, which really rotates. Useful as those tips can be, especially for digging at heavy deposits, they sometimes make patients complain. Metal stacks on magnetoscriptive inserts, which can bend, can make vibration even worse. By comparison, piezo tips are more fiddly for you to change out, but they’re gentler on your patient. You only use the sides of this kind of tip, and it doesn’t whirl like an Evinrude propeller. The clinical effect is about like that of a Gracey curette. The handpiece is wide, too, which makes it easier for you to work with.

But there are other concerns with the two types. Magnetostrictive handpieces are not always safe for patients with old-style, unshielded pacemakers, importantly. Piezo ones are pacemaker-safe. Piezo ones also use less water to control heat, a conceivable safety factor for patients who may have trouble breathing. Why use the magnetostrictive scalers at all? Because they’re faster. By a lot.

Informal literature suggests that patient preference is split evenly between the two types of ultrasonics. Most dental practices use only the magneto kind; a minority use both. Only a few use the piezos alone, though the number is growing. The price differential between the two is not very big, if one shops carefully. Surveyed hygienists, confusingly, strongly prefer the results they get with magnetostrictives, but also believe that piezoelectrics, because they’re gentle and seem modern and advanced to patients, are the way of the future.

Recent investigation of patient preference is turning up surprises, however. A careful study [1] in Japanese patients undergoing supragingival scaling with both instruments, evaluating discomfort, pain, sound, vibration, hyperesthesia, and treatment time, showed amelioration of complaints in 74%, 65%, 80%, 67%, 57% and 53% of subjects in magnetostrictive treatment, respectively. Patients preferred the old-fashioned way, in other words.

[1] Ikeda Y, Kawada A, Tanaka D, Ikeda E, Kobayashi H, Iwata T. A comparative questionnaire study of patient complaint levels between magnetostrictive ultrasonic scaler (Cavitron^® ) and piezoelectric ultrasonic scalers. Int J Dent Hyg. 2021 Aug;19(3):273-278. doi: 10.1111/idh.12478.