I had this tooth -- a bottom molar -- with a history of trouble. First, it was one of the ones that needed a really big filling when I finally stopped being a poor grad student and got the dozen fillings I needed. But the filling broke, and I had to get a crown put on it. (I also switched dentists.)
Then, about a year and a half ago, I think, one afternoon during lunch it started getting heat-sensitive, and then it started really hurting A LOT. I had to keep cold water on it all the time or it was just unbearable. So I went to the dentist and said "you need to do something about this right now", and she drilled it out and packed it with anaesthetic stuff that would finish off killing the nerve, and I got a root canal a week or two later. (The root canal, it turned out, was really no big deal -- it was a lot like getting a filling, it just took three times as long.)
Well, for the last couple days, that same tooth had started being temperature- and pressure-sensitive again from time to time, and this morning it started hurting. And again with the needing to keep cold water on it or else ow. So I went straight to the dentist, didn't even go to work, and she had a look at it.
Apparently, the other nerve was calcified (which was why they couldn't get it with the root canal) and it was probably dying. I was a little perplexed when it first started to hurt, because I was like, "it's DEAD, how can it hurt?!", and the calcified-other-nerve explains that. Plus, the tooth probably had vertical cracks, which don't show up on X-rays, in it. She said she could send me to a specialist to have them diagnose it, but in her experience (and she herself had a tooth that did the same thing), they're basically never salvageable in this condition.
So, she pulled it.
It took a while, but it didn't really hurt. I'm on percoset now, waiting for the novocaine to wear off. We'll see how long that takes, since the injection hit the nerve directly (there's an electric sensation when that happens), dammit, which means it's probably traumatized and will take weeks for the numbness to go away completely. I'm already starting the vitamin B regimen to help it along.
I switched the gauze in my mouth a few minutes ago and spat out the most disgusting giant blob of jellied blood I've ever seen. Ewwwww!
Lunch is a protein shake. Dinner will probably be another protein shake and pudding. *sigh*
Teeth: yet another argument against Intelligent Design.
UPDATE: Awesome! The novocaine appears to be wearing off without a problem! The "electric sensation" is a classic sign of a direct hit on the nerve. It didn't happen the time I did get nerve trauma, and this time it did happen but there's no trauma. Waaaaaacky.