How many semesters of toxicology and human physiology can we suppose the average dentist - that is out there advocating for the phosphate fertilizer industry's interest in fluoridating public water systems - received in their schooling?
How do these advocating dentists answer to the question of dosage, since infants being raised on formula would be receiving about 3 times what an adult would just in the water - let alone that some infant formulas actually contain fluoride in their composition. What about construction workers - particularly in summer - that likely consume more than twice the amount of water as the average adult. What about Hispanics that are far more sensitive to the negative side effects of fluoride, as well as blacks that are about twice as sensitive as Hispanics?
The dental associations are not only in the back pocket of fluoride producers like the phosphate fertilizer and aluminum industries, but they are defensive about the subject because of the massive liability they are piling onto year after year, for continuing to advocate for fluoride.
Same reason they continue to pretend there are no harmful health effects that result from amalgam fillings. They stand to suffer extreme exposure to stand liable to all those they negatively impacted with them - particularly after those negative health effects became so widely known.