Crown fell out

Toothsmith

There is no way anything the hygienist does can CAUSE such damage to a crown.

It is very possible that a crown, or filling or tooth that is on the verge of coming off or breaking will just be tipped off by the hygienist, or even by a dentist doing a decent check-up.

So anything that falls off/to bits whilst a hygienist is working would probably have broken on the very next meal anyway. Certainly at sometime in the very near future.

Back to the original post:- A crown with a post on it looks like it just fits into the gum - but it doesn't. There will still be your own root down there, and that's what the crown cements into. These bits of root are very prone to breaking though. So sometimes, it will be possible to re-cement the crown - if the root is still sound, and sometimes it won't.