Wikipedia also has an entry on fluoridation of water http://en.wikipedia.org/wiki/Water_fluoridation
This indicates that there are no harmful effects as long as the levels are monitored and natural fluoride levels are accounted for.
The side effects anyway are small and not at all horrific. See article.
I am not too sure Wikipedia is classed as a reliable source!
Even the article you indicate does not come out saying Fluoridation of water is bad and the levels it indicates as harmeful (5 - 10gms) is far far over what a normal person will be exposed to.
I would be, and am, much more worried about the widespread use of antibiotics and growth chemicals used in meat production around th world and in the residual effects of pesticides in fruit and veg.