Joel344 schrieb-ed:

True. But, well, let me play the devil´s advocate:

Didn´t our mutual friend, Tren Dean, once fabricate a "J"-shaped curve
showing a decrease in caries prevalence with increasing fluoride
concentration (up to a certain level)? As "the dose makes the poison"
(not primarily the concentration), the same effect should be seen if a
person drinks one litre of 1 ppm fluoride-containing water or two liters
of  0.5 ppm fluoride-containing water. There should, then, be a
difference between people drinking different amounts of the same water.

(Rhetoric) Question: How did he discriminate in his studies, which
"children" drank how much water and, thus, got what fluoride dose?

Peter