So a piece of filling just came out,
A piece of filling coming out means that the rest of the filling must be taken down and another one must be put to fill the entire cavity. Just another piece of filling replacing the old one wouldn't bond with the one that didn' fell.
. And that's assuming they won't try and drag me into doing more work on other teeth.
I hope that your dentist is an honest one and will just recommend you other dental work that is absolutely necessary.
You can ask him to show you with the mirror the tooth that he says that he needs to redo, so you can see for yourself what he sees, the reasons for which he has to replace other fillings.
The questions about reactivity and hyperacusis are very important.
If more visits to the dentists are necessary, try to spread them apart.
Having T doesn't mean that you can let your teeth go to hell. Not going in time for a dental problem means more visits to the dentist later on, to fix a bigger problem.
Even for adjusting dentures you will hear some drilling, so there is no way around it.
You can use earplugs and ask the dentist not to drill a lot at a time, but to take breaks.