Perhaps I should clarify things a bit:
exDemMom, PhD, Biochemistry and Molecular Biology. Current research focus: toxicology.
I think I do know something about fluoride. It's been mentioned in a few classes I had to take along the way. I know even more about poisons in general: the dose makes the poison. In other words, these anti-fluoride screeds spend a lot of time detailing the horrors of fluoride poisoning, without ever mentioning that the doses needed to cause such spectacular effects are hundreds or thousands (or more) times higher than the typical daily dose from toothpaste and fluoridated water.
Your body, I might add, has a wonderful system for removing poisons: the liver and kidneys. Without them, we'd be dead, since toxins are present in virtually all the food we eat (that includes the "natural" and "organic" stuff, too). The only way to avoid ingesting poison is to avoid eating, drinking, breathing, or touching anything.