The google/startpage search results for "fluoride in water vs toothpaste" are almost as heavily curated as searching for information about COVID. That alone should tell you something.

Most water companies add 0.5 to 1.0 mg of fluoride per liter of water.

The fluorides added to water (sodium fluoride and hydrofluorosilicic acid) is NOT the same as fluoride found naturally in water (calcium fluoride). Sodium fluoride is added to toothpaste as well.

Unlike calcium fluoride, sodium fluoride is readily absorbed by your body and is not naturally-occurring. Before it became known as the "miracle" of modern dentistry, sodium fluoride was just industrial toxic waste. To get the sodium fluoride in toothpaste to work, the toothpaste needs to be acidic, so while it does mineralize your teeth, it also erodes your tooth enamel at the same time.

More concerning is hydrofluorosilicic acid, which is also toxic waste, as hydrofluorosilicic acid is often contaminated with arsenic (a known carcinogen), and also leaches lead from plumbing. This shit is added to drinking water.

The smarter thing to do is to ditch fluoride entirely, filter it from your drinking water, brush with non-fluoridated toothpaste, and instead use microcrystaline hydroxyapatite to remineralize your teeth. You want hydroxyapatite sourced from cow bones, not the nanomolecular synthetic shit, because the nano hydroxyapatite is relatively unstudied and could behave like asbestos or talcum powder.

Brush your teeth with essential oils and use hydroxyapatite to mineralize your teeth. We shouldn't be adding toxic fluoride to drinking water. Fluoridated toothpaste for kids with their baby teeth is fucking idiotic, and fluoridated toothpaste for anyone is unnecessary when you can get the same results from hydroxyapatite without any toxicity. If you are some vegan ideologue freak, use the fluoridated toothpaste, but rinse like five times and make sure you get all of that shit out of your mouth.