Can a Handheld Rechargeable "Ultrasonic" Scaler Be Turned Into a Cutter? (Spoiler: Nope)

I made a compact DIY ultrasonic knife by modifying an ultrasonic dental scaler I purchased from China for a little over $100. It worked great for fine detail work.

Well, someone showed me that there are also small, handheld, rechargeable "ultrasonic scalers" available for around $20. Could they also be made to work? I decided to purchase one to find out. It arrived today. The answer is no.

A roughly $20 "ultrasonic scaler" that -- spoiler alert -- is not ultrasonic.

So why not? Because the tool is not ultrasonic, meaning it does not vibrate at ultrasonic speeds (over 20,000 Hz) To do that, one requires an ultrasonic transducer. The transducer will vibrate the tip a tiny amount at super high frequencies. As a result of this motion, the tip gains some mild superpowers when it comes to breaking up different stuff, such as -- in the case of dental scalers -- breaking up hard calculus (tartar) on teeth without damaging the teeth themselves.

These tools may be advertised by sellers as "ultrasonic scalers" but they do not contain a transducer. In fact, the product packaging and manual themselves make no claims of being ultrasonic. It's just a vibe motor -- much like the one that vibrates your phone, or a cheap electric toothbrush. And that's all it is. A handheld vibe motor with a dental scaling tip on it.

I burned the $20 so you don't have to! eBay uses the magic word "ultrasonic" in the name and description of these tools but they are not. Maybe I can make a micro sanding tool out of it or something, but I won't be making an ultrasonic cutter out of it, that's for sure.