The reason I use a vet instead of a dentist is that in my state, only vets can sedate.
I'm pretty sure that's the law for every state, cori.
Since equine dentists aren't medical practitioners they're not allowed to use sedation drugs, because sedation is a medical procedure.
If your horse needs sedation to float, then you pay the vet and
the equine dentist. I'd much rather just pay the vet.
Mine uses a manual float, but I've also had my horses done with power floats. As long as they're careful, the power floats work great and take less time.