5 years ago, I had a root canal on an upper left molar (#14). I never got a crown for financial reasons and basically forgot all about it because there was no pain. However, several months ago, I was eating something and the tooth cracked. Apparently the crack was severe and extended to the gum. I had the cracked fragment removed. There was some pain associated with the crack (I was told by the dentist that this was really due to the cut in the gums, not the tooth), but for the most part, the tooth did not hurt still. Last week I had crown lengthening surgery, which resulted in a lot of soreness around tooth (mostly gum pain but also some tooth pain), and yesterday I had a crown prep procedure. Now my tooth hurts a LOT and is very sensitive when I touch/tap it. Could this possibly mean that the root canal was not successful?? I am going to get a crown in a few days and I want to know if there are any other possible complications, or whether it is normal for my tooth to be in so much pain due to just the crown prep. Thank you!