I had this really deep cavity filled 4 years ago and the dentist said it's so deep it might need a root canal later on, if it will not heal. In the beginning it was all fine, felt no pain. But then I started feeling extreme sensitivity to cold and my dentist tried pushing off the root canal as much as possible. But then i couldn't handle it so i had the root canal done. I've never felt any pain since then. Now i feel that same pain from cold things in the same teeth that i felt before having the RC done. Any ideas what this can be from? i had a cleaning done two weeks ago, when i started feeling the pain, and my dentist said i was free of cavities or other problems. said the pain will go away on its own...