Flouride is toxic, period. The argument that you are likely trying to make, to oppose my statement, is how much of it can a person ingest before having negative health effects and is it really good for your teeth. It might be better to read about its history of usage, and that many countries do not allow flouride in their drinking water, and have a cavity rate that is equal or less than that of the U.S.
Some communities have a naturally-occurring fluoride level higher than the amount that is added in other communities for tooth health. (As described at your link, these places see some cases of fluorosis, but no one dies of cancer.) That is, only very small non-toxic amounts of fluoride are ever added. These amounts have radically improved the oral health of children in those communities. Poor children, who have little access to dentists in red states, would be especially harmed if cranks have their way and fluoridation ceases.
Let me guess, you also don't want iodine to be added to salt?
https://www.primallifeorganics.com/blogs/primal-life-organic... (The Neurotoxin Lurking in Medicine Cabinets Around the Globe)
https://origins.osu.edu/article/toxic-treatment-fluorides-tr... (Fluoride's Transformation from Industrial Waste to Public Health Miracle)