My back crown just came off but there's no pain. Why not? Never had a root canal.

This back bottom tooth has been aching a little for a couple weeks. I’m chewing gum and the crown, nine years old, came off. What’s left is a silver “crown” looking thing-no skin- and I don’t know what it is and I don’t know why it doesn’t hurt to chew on it. Why not?
I have rotten luck with crowns unless they’re gold and I don’t understand that either!