For everyone who hasn't heard, fluoride doesn't prevent tooth decay. It does however harden your arteries.
http://www.activistpost.com/2012/01/new-research-fluoride-linked-to-1-cause.html

http://www.mbschachter.com/dangers_of_fluoride_and_fluorida.htm

http://naturaldentistry.us/1378/the-dangers-of-fluoride/

These are just two. If you type fluoride dangers into dogpile you'll get a lot more hits. From what I understand fluoride is a byproduct of aluminum and fertilizer manufacturing. It is not a vitamin and it is not approved by the FDA. It may have topical benefits but no benefits and many risks are associated with consumption. If you choose to use it directly on teeth I caution you to be very careful not to swallow any if possible, and do your best to make sure it's not in your drinking water. To me the risks highly outweigh any unproven benefits so I avoid it altogether.

Fluoride is naturally occurring in trace amounts in most freshwater and saltwater sources and has been for thousands of years. I imagine as long as you do not consume too much, that it is perfectly ok. You can die from drinking too much water, too, of course.

The key word being trace amounts Cheese. And not all fluoride is equal in terms of safety either.

I'll just copy this from the link above:Research shows fluoridation is unnecessary since we’re already receiving 300% or more of the American Dental Association’s recommended daily amount. The chemicals used for fluoridation are not high purity, pharmaceutical quality products. Rather they are byproducts of aluminum and fertilizer manufacturing and contain a high concentration of toxins and heavy metals such as arsenic, lead and chromium. All proven to be carcinogens (cancer causing).

So the point is they're putting toxic fluoride in our water and way too much of it. Then encouraging people to ingest more which by all tests is dangerous!