In reality what will happen is that rich kids will be just fine because they will get their fluoride treatments at the dentist every six months.
It's the poor kids who will suffer because they don't see the dentist regularly because it's expensive, so they won't get their treatments.
As for “fluoride treatments”, those are applied to the teeth, not drank. They are not a substitute for regular brushing.
It is true that many studies were at higher doses(2x to 4x), but that should not mean that it is acceptable to intentionally raise fluoride levels to half of harmful levels, because we want to protect teeth.
If you don't want cavities decrease sucrose, brush and floss. Can I brush my teeth with use baking soda, use whatever? Arent they are OUR teeth? What if we find some additive might help some other health issue? Should we add that to everyone's drinking water?
At safe levels fluoridation is a public health measure akin to fortifying foods with vitamins (e.g., iodine in salt or folic acid in flour something we do all the time).
That's a very high standard of evidence.
Toxicity testing is often carried out on mice, up to the dosage required for any observable effect. From that safe levels for humans are derived, e.g. the NOAEL (No Observed Adverse Effect Level).
To say that a study done in humans, got observable effects at only twice the intended dose (who knows what the s.d. of the dose is, but anyway) and we conclude there's simply not enough evidence?
Many chemicals have been banned on the basis of far less evidence.
Consider the following: Many water sources have a ton of salts and such in them naturally. Fluoride being one of them. The reason why water fluoridation became a thing in the first place is because it was noticed that higher natural levels of fluoridation resulted in fewer caries.
Water treatment in order to make it safe to drink often involves processes that remove and filter out these minerals and chemicals. Which means said things need to be added back in, as part of the treatment process.
Also, fluoride helps with remineralisation when it is used pretty much regularly, not once per 6 months. Fluoride treatments once per 6 months are not gonna bring back the enamel lost.
I do not understand what is the big deal here. In many countries there are specific recommendations wrt to fluoride and kids brushing their teeth that seem to work fine. This seems to be a solved issue in many places in the world without fluoridating water.