# Why Is Fluoride So Good For Your Teeth? **URL:** \ **Category:** In My Humble Opinion\ **Created:** [June 22, 2022, 2:54pm UTC](https://boards.straightdope.com/t/why-is-fluoride-so-good-for-your-teeth/966634 "2022-06-22T14:54:06Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![Jim\_B](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jim_b/32/4338_2.png) [@Jim\_B](https://boards.straightdope.com/u/Jim_B)\ **Post date:** [June 22, 2022, 2:54pm UTC](https://boards.straightdope.com/t/why-is-fluoride-so-good-for-your-teeth/966634/1 "2022-06-22T14:54:06Z")
You have to admit, modern dentistry wouldn’t be where it’s at without fluoride. Where I live they even put it in the water. What makes fluoride so good for your teeth? It’s an element. (Okay, you chemists out there. It’s an _-ide_ of fluorine, because fluorine is poisonous. I know that 🙂 . But still.) What makes it so special and so uniquely associated with our teeth? And last question, is it indeed a nutrient necessary in human nutrition, like Potassium or Iron? Thank you in advance for your helpful replies 🙂 . ---
**Author:** ![Johnny\_Bravo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_bravo/32/493_2.png) [@Johnny\_Bravo](https://boards.straightdope.com/u/Johnny_Bravo)\ **Post date:** [June 22, 2022, 2:58pm UTC](https://boards.straightdope.com/t/why-is-fluoride-so-good-for-your-teeth/966634/2 "2022-06-22T14:58:57Z")
From the CDC: > Fluoride works by stopping or even reversing the tooth decay process—it keeps tooth enamel strong and solid. Tooth decay is caused by certain bacteria in the mouth. When a person eats sugar and other refined carbohydrates, these bacteria produce acid that removes minerals from the surface of the tooth. Fluoride helps to remineralize tooth surfaces and prevents cavities from forming. Per your second question, it is not considered an essential mineral. ---
**Author:** ![naita](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/naita/32/5862_2.png) [@naita](https://boards.straightdope.com/u/naita)\ **Post date:** [June 22, 2022, 3:48pm UTC](https://boards.straightdope.com/t/why-is-fluoride-so-good-for-your-teeth/966634/3 "2022-06-22T15:48:39Z")
A more technical explanation: > Fluoride catalyzes the diffusion of calcium and phosphate into the tooth surface, which in turn [remineralizes](https://en.wikipedia.org/wiki/Remineralisation_of_teeth) the crystalline structures in a dental cavity. The remineralized tooth surfaces contain fluoridated [hydroxyapatite](https://en.wikipedia.org/wiki/Hydroxyapatite) and [fluorapatite](https://en.wikipedia.org/wiki/Fluorapatite), which resist acid attack much better than the original tooth did. > [Tooth enamel - Wikipedia](https://en.wikipedia.org/wiki/Tooth_enamel#Fluoride_remineralization) It helps restore damaged enamel, and the restored enamel is more resistant to acid, which is what damaged it in the first place. (Oral bacteria produce acids when digesting sugars in your mouth.) ---
**Author:** ![Jackmannii](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jackmannii/32/311_2.png) [@Jackmannii](https://boards.straightdope.com/u/Jackmannii)\ **Post date:** [June 22, 2022, 4:11pm UTC](https://boards.straightdope.com/t/why-is-fluoride-so-good-for-your-teeth/966634/4 "2022-06-22T16:11:25Z")
> [@Jim\_B](#): > > Where I live they even put it in the water. No! Actually, close to 3 in 4 Americans have fluoridated water supplies - that is, with fluoride concentrations sufficient to prevent tooth decay (all drinking water naturally contains fluoride to some extent). ---
**Author:** ![Mallard](https://avatars.discourse-cdn.com/v4/letter/m/b9bd4f/32.png) [@Mallard](https://boards.straightdope.com/u/Mallard)\ **Post date:** [June 24, 2022, 7:48pm UTC](https://boards.straightdope.com/t/why-is-fluoride-so-good-for-your-teeth/966634/5 "2022-06-24T19:48:55Z")
I’ve lived in a jurisdiction that’s had fluoridated water since I was a child and I went for a 50 year period without a “new” cavity. 1970-2020(age 18-68). Had to have some old fillings replaced over the years, however. I’m sure fluoride had something to do with it. ---
**Author:** ![ekedolphin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ekedolphin/32/10003_2.png) [@ekedolphin](https://boards.straightdope.com/u/ekedolphin)\ **Post date:** [June 24, 2022, 7:53pm UTC](https://boards.straightdope.com/t/why-is-fluoride-so-good-for-your-teeth/966634/6 "2022-06-24T19:53:38Z")
Why is there a conspiracy theory that fluoride is a deadly poison? Are people confusing it with fluorine? ---
**Author:** ![rsat3acr](https://avatars.discourse-cdn.com/v4/letter/r/a3d4f5/32.png) [@rsat3acr](https://boards.straightdope.com/u/rsat3acr)\ **Post date:** [June 24, 2022, 8:23pm UTC](https://boards.straightdope.com/t/why-is-fluoride-so-good-for-your-teeth/966634/7 "2022-06-24T20:23:39Z")
Dentist here. Fluoride is good for your teeth because it makes the enamel in your teeth harder when it is incorporated in the mineral component of teeth either during initial formation of the enamel through systemic fluoride or by topical application after the enamel has formed. Yes fluoride is a poison, but like all poisons it is dose related. Too much fluoride could kill you but so could too much salt or vitamin A. It would be difficult to ingest enough to kill you unless you tried. In my over 36 years of doing this I recall one death from fluoride. IIRC an toddler was given fluoride trays and left unsupervised. He swallowed the fluoride and died a couple of days later of kidney failure. I believe it was thirtyish years ago in El Paso. Why they used fluoride trays instead of varnish or even a rinse is beyond me and then to leave unsupervised, stupid. ---
**Author:** ![Jackmannii](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jackmannii/32/311_2.png) [@Jackmannii](https://boards.straightdope.com/u/Jackmannii)\ **Post date:** [June 24, 2022, 11:46pm UTC](https://boards.straightdope.com/t/why-is-fluoride-so-good-for-your-teeth/966634/8 "2022-06-24T23:46:57Z")
> [@ekedolphin](#): > > Why is there a conspiracy theory that fluoride is a deadly poison? Are people confusing it with fluorine? Sodium fluoroacetate (a compound not employed in municipal water fluoridation) has been used as a pesticide and rodenticide. “X” is a poison/has been used as a poison" is a favorite argument of the kind of people who triumphantly point to early chemotherapeutic drugs being derived from WWI chemical warfare agents. Dosage, chemical formulation and mode of use matter. \*the most common fluoride compound used in water fluoridation is [fluorosilicic acid](https://www.cdc.gov/fluoridation/engineering/wfadditives.htm); all such compounds produce the same fluoride ions and are metabolized similarly.