It's marginally beneficial to dental health. The whole story of how that was discovered is very interesting.
There was a town in Colorado, can't remember the name, who's spring was contaminated with Flouride. The people had all the classic symptoms that are now associated with Flouride poisoning, including
dental flourosis.
BigDave, where's the theory? Flouride is a toxic chemical. What's theoretical about that. I get so tired of seeing the phrase "conspiracy theory" being used as a derogative.