Hi. About 20 years ago I had a root canal filling in one of my front lower teeth. I have never had a problem with this. Then about 18mths ago I had another top back - Tooth 16. I had nothing but problems and continual pain & finally had it out about 3 weeks ago. A couple of days after finishing antibiotics the bottom tooth that I have a root canal in started getting sore and has been really sore ever since, at times aching, but real pain if a bite hard on it, or knock it with a fork or anything. If I rub the gum underneath it is really sore. I know there can be major problems with root canals and wonder how this can be linked??