I can remember when fluoride issues were a conspiracy theory
Oh, it still is. Healdsburg adds fluoride to its water, and every couple of years the tin foil crew gets a ballot measure to remove the fluoride.
We have a pretty decent sized lower income population, that can't really get a lot of dental care, often happening when dentists do big sessions at a high school gym or something. Dentists from around the county will do a kids dental drive at a rotating set of towns. They are very clear in saying that the kids in Healdsburg have much less decay than the towns that don't fluoridate.
It's less obvious in places where most people have money and can send their kids to the dentist, make sure they have brushes and toothpaste, put capping material on the pockets of molars, etc...