I'm probably in the minority but I think the relatively new requirement of floating every 6 months to a year is a overblown. I really does depend on your horse, his age, his diet, and his teeth. I have two geldings in their 20s--they didn't have their teeth floated until their late teens and they are still in excellent health. One of them doesn't drop a bit of whole oats, and the vet said he doesn't even need floating.. On the other hand, I have an 8 year old mare that grinds her teeth when she eats and drops feed all over the place; she's in great shape, but I have hers done more often. I have a 12-year old stallion who drops feed; I had the dentist come, and he floated his teeth, but he noted the reason he drops grain in because one of his teeth grew in wrong, and there's a gap. It would need surgery.
All I'm saying is that floating is expensive, and if your horse ends up with big "hooks" on the side of his teeth and really has trouble eating, then it's a problem. Otherwise, be careful how you spend your money.