74.6% of Americans get fluoridated tap water; https://jada.ada.org/article/S0002-8177(24)00204-6/fulltext shows that even with instructions to brush and floss and instructions to use it, water flouridation reduces cavities in a community by at least 20%.
About 60% of bottled water in the US is sourced from municipal tap water systems:
https://www.nyruralwater.org/news/study-shows-nearly-64-bott...
74.6% of Americans get fluoridated tap water; https://jada.ada.org/article/S0002-8177(24)00204-6/fulltext shows that even with instructions to brush and floss and instructions to use it, water flouridation reduces cavities in a community by at least 20%.