It's not all that different from going to the dentist. I dread the build up to it, but once I'm in there it's not so bad.
Oh man, I had the most intense tooth cleaning experience when my wisdom teeth were
rotting in the back of my mouth. It was like the release during sex, but continual. The
hygienist kept asking if I was in pain, since I was tensing up so much, but it wasn't
precisely pain - rather a feeling which wasn't quite describable.
I've had some pretty extreme pains (though no broken bones or the like), and none of them
felt anything like this.