Only one thing has ever made me comfortable sitting in that dentists chair - acupuncture! It probably sounds sort of funny because many people who fear the dentist also fear needles - but if you can get past that part (not so difficult, really) it can really help. First of all, there are treatments you can get to dampen pain. One of my professors tells a story where he was going to get a dental procedure (filling, I think) and did a 45 minute stimulation of a point called Large Intestine 4, which is on the hand. He then left for the dentist.
He requested no anesthesia and after some discussion, they allowed it. It was in Germany - I'm not sure you could get an American dentist to do that. Anyway, he had the procedure and there was no problem. I asked him what he thought about more serious procedures and if acupuncture could do anything about the extreme tension people go through before going to a dentist. There are several very simple treatments that can be done for general relaxation - adding the pain dampening treatments on top and you have a recipe for an ok treatment.
At least that has been my experience. I've done this for my last two dental visits (one a root canal and crown in the same visit) and not only do I have no discomfort, I don't work myself into a panic attack before the visit and I also seem to recover from the anesthesia much faster.
Just a thought!