The same thing happened to me last month but with chips. You just get a filling (I think) and it's pretty easy and painless aside from the shot....which they fucked up mine and numbed both sides so yeah.
OP, do you have a night guard? I grind my teeth/mash them/bite them against each other when I sleep and I was super concerned it about it hurting my teeth so I went to my dentist and got a night guard. Perhaps look into getting one, if you don't already?
it has always been my greatest fear as well. as I've said before I getting my teeth at night so I have quite a few nightmares of all my teeth falling out. ..so today has sucked.