This doesn't seem right to me. I've had some pretty extensive dental work done, including some really ugly extractions, all under consious sedation as others have mentioned. (Where basically, you are asleep and won't feel or remember anything, yet you are still breathing on your own.) I also recently had surgery on my achilles tendon without requiring general anesthesia -- they can do some pretty amazing things without having to put you completely under, so it's odd to me your dentist would want to do this.