I had a root canal over a year ago. the molar that was affected had a crown. My dentist went through the crown to do the root canal then sealed it with a filling, which I'm sure is a standard procedure. My problem is that it still is extremely sensitive to the bite. if I iput any pressure on it at all it is sensitive. If i have any sucking in that area it sends me through the roof. I called my dentist several times, visited him once where he ground my tooth for a better bite. this helped for about a month and it started to be sensitive again. I've had my teeth cleaned, at my dentist, and they said that it could take up to a year to feel back to normal. It's now over a year and I don't see any difference. If this is normal then I need to know that.