Comraddict said:
I'm having two on Wednesday - both teeth have abscesses. So it shouldn't hurt.
LMAO now because of me everyone on CFC is gonna wait to have an abscess before going to the dentist :S but pretty please don't do that

'coz if abscesses are quiet benign, they can easily evoluate into massive and critical facial infections (which can even threaten life pronostic...)
And just to warn you, it can still hurt. Depend on the type of infection/abscess. If it's not hurting you right now, spontaneously, there are big chances it won't hurt you when you get the canal treatment.
Also, for molars and 1rst upper bicuspids, you have more than 2 roots, so you can have a necrosed part while the other part will still be only inflamated (and you can't just root canal half of a tooth, if you do it it's for the entire pulp)
Good luck Comraddict

and just concentrate on the fact, that if it's quiet painfull, it's a pain for a greater good (you don't want to have pus evacuating directly into your mouth do you??)
I wish my worst ever pain was from a root canal. I had to get two wisdom teeth pulled (upper and lower). The many shots I took somehow did not do enough of a job stopping the endless pain for the hour.
The top one was relatively easy enough to remove but the lower one was a mix of several kinds of pain. It has not fully pushed out so the tooth had to be drilled to the point of burning, cut to divide it, and individually pulled out after working each piece like you do with loose teeth. My fourth wisdom tooth was barely a bump in my gums so thankfully I was spared even more shots and pain. I had tears streaming from the pain, stitches, my mouth was flowing with blood for hours and had to be drained quickly, and a puffed face that effectively closed an eye.
Had a wisdom tooth pulled out myself, by a professor (and friend) from the hospital (needless to say, I asked him because he's quiet competent). Lower wisdom tooth (these are hard to painkill 'coz the bone around them is kinda compact and novocain doesn't diffuse well through it). Took 1h15. I actually felt the pain the whole way (when it was getting to hurting I asked him to shot me once more. He had to drill the toth to cut it to 3 parts, and to drill the jaw bone around the tooth in order to have access to the root. When he finished I asked him if I could see the work in a mirror, he answered : No I wont let you, I actually had to butcher you.
Worst thing though was the taste of burnt dentin in the back of my throat (because I knew what that taste was

), and it took me 2 months to be able to open my mouth completly (because of the swelling)
Still he did a good work, and I'm going back for the upper one to equilibrate jaw relationship (though, as you said, upper wisdom teeth are much easier, and also much easier to painkill which is a good point for the patient)
You can always have all 4 removed at once at the hospital, but I wanted to be awake to follow the procedure, and when you're awake the surgeon tends to be a lot less agressive (true!!!)