No, it is a poison and we get all the fluoride we need from other sources. Adding it to the water supply is mass medication and is wholly unethical. There are no benefits whatsoever in adding it to water. How can adding it carte blanche be beneficial...how is the dose regulated, how do you determine how much each individual has consumed?
When you drink fluoridated water it passes the teeth, is absorbed into the body and begins affecting bone and the pineal gland. It doesn't home in on teeth! It affects the whole body.
Use fluoridated tooth paste if you want to get the best benefit. But it should be an individual choice not some nanny state directive.