Q. I had 2 crowns at the back upper side replaced and one new one (so they are 3 in a row) and root canal prior to this.. I also had root canal on the other side of my back upper side and these teeth were then filled (2 of them). that was about a month ago and when I bite both sides of these teeth are in such pain that I avoid chewing at all! I Also the teeth that have had root canal are sensitive to cold…I thought if your teeth are dead you can’t feel anything??