Mass medication via fluoridated water puts certain groups of people at risk. It is a reckless and criminal practice that most countries prohibit. Since everyone drinks different amounts of water, there is no way to control how much fluoride people consume. It is therefore impossible to safely control what dosage of fluoride a person receives via the water supply. In other words, most of us.
Poor nutrition is widespread throughout America.
Furthermore, adult-onset diabetes is becoming increasingly prevalent in children. This disease adversely affects kidney function, which means more fluoride will be retained by the body building lifetime levels that will have serious consequences later. We don't really know, but California provides a good example. Furthermore, any projected savings to taxpayers because of reduced dental caries is obliterated by the high cost of dealing with the many health problems associated with the consumption of excess fluoride. Because fluoride compounds are so corrosive, water treatment plants must replace their equipment more often, as well as buy and add mass amounts of anti-corrosive chemicals.