Over 5 years ago, I had a root canal and crown done on a lower back molar. It was still very sensitive after treatment. After my insistence that the pain was still there, the dentist thought it was referred pain from the molar behind it, so I got a root canal and crown on that tooth as well, several years ago. I'm still experiencing pain to hot and cold and sensitivity to sweet. I'm sure it is one of those two molars. I have been back to the endodontist who checked the teeth with both hot and cold, and I had no reaction. The gum around and between the teeth seems sensitive to me as well. One of the crowns is receding (I don't think the fit was right from the beginning) and needs to be replaced, the other crown needed a filling to close a gap. After the 2nd crown got the filling, my sensitivity decreased by about 95% for 6 months or so. One night at dinner, a hot soup set it off again, I went weeks with incremental throbbing in the area. The dentist and endodontist insist that the root canals have not failed and there is nothing more they can do. I'm wondering if the gum or area around the tooth can be sensitive (there is no noticeable swelling). Or can something else be wrong? I'm at a loss, since I've now been to 4 different dentists and one endodontist who claim it can't be happening. Help?! Also--whenever my tooth becomes sensitive, I start tapping on teeth trying to narrow it down--the only two teeth that seem to be sensitive are the two with root canals and crowns. It doesn't make any logical sense at all, but it still seems to be happening.