# Another toothpaste question

**URL:** <https://boards.straightdope.com/t/another-toothpaste-question/110119>\
**Category:** Factual Questions\
**Created:** [May 21, 2002, 4:10pm UTC](https://boards.straightdope.com/t/another-toothpaste-question/110119 "2002-05-21T16:10:52Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Crafter\_Man](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crafter_man/32/458_2.png) [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)\
**Post date:** [May 21, 2002, 4:10pm UTC](https://boards.straightdope.com/t/another-toothpaste-question/110119/1 "2002-05-21T16:10:52Z")

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If I understand correctly, water is fluoridated with the goal of getting fluoride _into_ your body and eventually reaching your teeth.

So how does fluoride in toothpaste work?

Is there an assumption that you’ll swallow a little bit of toothpaste every time you brush your teeth, thereby getting fluoride into your body?

Or does the fluoride form a hard, microscopic layer on your teeth?

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**Author:** ![Yeah](https://avatars.discourse-cdn.com/v4/letter/y/dbc845/32.png) [@Yeah](https://boards.straightdope.com/u/Yeah)\
**Post date:** [May 21, 2002, 9:36pm UTC](https://boards.straightdope.com/t/another-toothpaste-question/110119/2 "2002-05-21T21:36:55Z")

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Topically applied fluoride binds directly to the enamel surface of the tooth.