Comment by jaredklewis

How has it been “solved?” There’s just tradeoffs.

There’s evidence that despite widespread availability of fluoride toothpaste and mouthwash, fluoridated drinking water improves dental outcomes at the population level.

There’s also evidence that at high levels (not the normal levels it is added at, but at higher levels which can happen on accident) fluoride may reduce IQ.

I’m ok with either trade off but the “solved” phrasing makes it sound like there is an obviously superior choice.