Recently a dental hygenist told me that kids should start seeing the dentist starting at age 6 months, for "preventive care" since so many babies get baby bottle mouth.
Um . . .
My daughter didn't visit the dentist until she was 4, and my 4 yo son has not gone yet because I know he'd be totally freaked out- I see no reason to subject him to that until he's ready. Otherwise he could develop a very unhealthy view of dental visits, and fear them when he may really need them someday.
We have never supplemented flouride and avoid flouride toothpaste as well- and our kids have never had problems with their teeth, cavities or otherwise.
They eat a very healthy whole foods organic diet, with almost no sugar. They do not drink juices, only teas, and water, and occasionally milk. We brush their teeth in the morning, and at night before bed.
That all being said, this is what has worked well for us but I think this is all a very personal thing depending on your child. If your child is ready to see the dentist younger than that than I see no problem with it. If your child has problems with tooth decay, then flouride is probably a good idea. And I have known kids with perfectly healthy lifestyles whose teeth for some reason have decay problems.