I posted a problem I thought was related to my gums a few weeks ago. About 10 years ago I had a root canal and crown done and it has been bothering me off and on since then. Well, I moved and went to a new dentist who x-ray the tooth and noticed that the first dentist did not go far enough down the canal and the dentist claims that I have a low grade infection and need a retreat of the tooth. We have a kind of HMO dental insurance plan, so I don't think economics comes in play here. Does this seem right, that a low grade infection could be causing discomfort when I bite down or tap on the tooth?

yes an infection can cause sensitivity to biting. there are a few things that can cause pain when biting and this is one of them.