I love that this is the state of public discourse even on hacker news. Just accuse something of being like anti-vax and the down votes follow. No critical thought required.
Someone participating in this discussion would either know this from general knowledge, or could look it up.
People aren't that ignorant.
You have only to look up the rates of tooth decay among non-fluoridated countries to find that there is no difference whatsoever.
It doesn't matter what theirs is, the link I gave you isn't useful as a source, but as a list of sources.
Therefore, "anti-fluoride" seems fitting.
If you must dispute water fluoridation on Hacker News, do so by making careful, factual, respectful comments.
The site guidelines specifically ask you not to call names. That includes both calling each other names as well as calling each others' arguments names (e.g. "woo").