Comment by jiggawatts
21 days ago
That's just not true. Most of the studies simply compared areas with different amounts of natural fluoride in their local water supply, and applied some basic statistics comparing dental health. There have also been some A/B studies possible in areas that stopped or started using fluoride in their water.
Multiple such studies have been done, globally, over many decades.
I think it depends on how strict your criteria and evidence requirements are.
There are two Cochrane reviews that I saw on community water fluoridation:
https://pubmed.ncbi.nlm.nih.gov/26092033/
https://pubmed.ncbi.nlm.nih.gov/39362658/
There is limited modern evidence (ie. in a world where everyone is brushing their teeth with fluoride toothpaste) of some reduction in tooth decay in children. There were no studies on adults that met the review criteria.
Overall it seems like we just don't really know how much impact CWF currently has.