“Safety of ultrasonic toothbrushes when ultrasonic baths can cause arthritis?”

Hi there, when I worked in a lab with an ultrasonic cleaning bath, I was told to never put my hands in it because I could damage my joint tissue and develop arthritis (see refs 1 and 2 below). Can someone tell me that the frequency and intensity of an ultrasonic toothbrush is so much lower, that there is no damage to underlying tissue in the mouth and jaw? And that the power used by ultrasonic toothbrushes is way below the threshold to cause cavitation bubbles in underlying tissue and blood?

I've tried finding studies on scholar.google.com but I didn't find a study yet that primarily focussed on the safety of ultrasonic toothbrushes. Authors in the study (doi: 10.3290/j.ohpd.a37710a) in 2015 wrote that more data on safety is needed. I hope that an expert here will know more.

Ref 1)
http://www.soniclean.com.au/about/faqs#6
Can I put my hands into the water when my ultrasonic cleaner is activated?

As part of occupational health and safety, no part of the operator's body should be submerged into the water during operation as the ultrasonic energy is enough to cause damage to joint tissues and result in long-term arthritic conditions.

Ref 2)
https://www.bjultrasonic.com/can-i-put-my-hands-into-ultrasonic-cleaning-solution/
Can the Hands Be Immersed in the Ultrasonic Cleaning Solution While the Cleaning Process Is Ongoing?

Immersing the hands in the cleaning bath during the cleaning process is not advisable. When an ultrasonic cleaning process is ongoing, ultrasonic power produces ultrasonic waves that act on the cleaning solution to create cavitation bubbles. The implosions of these bubbles are intense and produce powerful energy. The implosions can cause skin irritations while the energy from implosions can harm the tissues of the joints. Rheumatic diseases can develop when joint tissues are harmed.