Comment by danny_codes

https://en.wikipedia.org/wiki/Opposition_to_water_fluoridati...

I draw your attention to the first sentence.

Also this is interesting:

Fluoridation may be useful in the U.S. because unlike most European countries, the U.S. does not have school-based dental care, many children do not visit a dentist regularly, and for many U.S. children water fluoridation is the prime source of exposure to fluoride.