I haven't had any drilling done but last time I went, the little suction thing was too loud. I would ask if they could not use that.
Tinnitus Talk Support Forum
There is a laser, I think it's called Waterlase, that can drill with very little noise. You just need to research dentists who are trained in using it. My dentist is and she is considered a holistic dentist. I researched it in case I need a filling in the future. I'm also going in every 3 months for a manual cleaning without automatic devices.
I have read some people taking NAC to help prevent any further issues. Know nothing about that myself
Tell your dentist you have tinnitus and can't tolerate loud sounds.