I use my vet because I prefer the horse to be sedated. I think it is easier, quicker and safer for everyone concerned and the vet can get on and do a much better job. The vets in my practise all go on regular courses to make sure they are good with teeth, because it is a good source of revenue for vets. My old horse had to be done every 6 months. My new one needs annual checks.
That is pretty much the same reason I use my vet! All of the vets in the surgery are fully qualified dentists aswell he came prepared to sedate my youngster yesterday but when he saw how chilled out she was he went for it without and she actually quite enoyed the experience (odd horse)
She is to be done again in 6 months when she is due her vaccination and then yearly after that