How our dentist handles it, is they call it a happy visit. They first introduce the child to all the dental type stuff and then do whatever the child allows them to. They don't push anything.
But the miss sat right down on the chair, all smiles, with her mouth open wide. The hygienist could tell that this was going to be a good visit. And the miss actually stayed for 45 minutes, getting the entire cleaning. They even tried x-rays, but the miss had a hard time biting the plate the correct way, so they decided to try next time.