My dentist charges until the deductible is met. I've always just paid before I leave the office, but I always have to ask them "what do I owe you?" I'm sure if I didn't they would bill me for any balances. There have actually been a couple of times over the last umpteen years that Carrie (reception/billing) has said let's just wait and see what insurance picks up, but those were situations where we didn't know if insurance would consider the work necessary or cosmetic.