The operation itself is quite vicious if you compare it to your average filling. The concept of a root canal is that the tooth's root is redundant: once the tooth grows to its full size, as in once you stop growing, the root doesn't do much and you could well live without it. Thus in cases where the root becomes troublesome it is simply sucked off and killed. What usually takes place is that the top of the tooth is removed, drilling is done through its center, the root is cleaned off the drilled hole (using tiny bottle brushes like tools), poison and antibiotics are poured into where the root once was, and then the root's previous home is filled with rubber. Yes, I was expecting some titanium alloy to go in there but instead you get a byproduct of oil. When all is done and dusted, a crown is placed over the tooth to make it look like a tooth. And there you go: you get to save the tooth but you're rid of the pain the tooth brought you.
You might think I've provided the above description to shock and awe you, as if to either scare you away from ever seeing a dentist or to show you how brave I am for going through this motion. That is not the case; my intention was to show root canal for the marvel it is. Think of the alternative: I certainly did while suffering a painful weekend on heavy pain killers while still going through unprecedented pain. Less than a hundred years ago, people had to compensate for the fact our teeth were never meant to last more than a few decades - why would they when, in evolutionary terms, most people died before they were 35 - by pulling their tooth out with a string? When looked upon this way, the fact we can go through a relatively painless operation called a root canal and get to keep our mouth looking nice and cool is a wonder of human ingenuity.
Still, I would rather wait a while before my next root canal.
Note the above photo was taken during the operation by my dentist. At first I took photos of my myself just so I could see what's taking place; then the dentist cooperated and took a couple of shots for me. She also arranged for me to hold a mirror instead...
You can see the bottle brush used to remove the root popping out of my tooth there. The full set of photos is on my Flickr page. As per my current policy, the photos are accessible to friends only.