Sciencemadness Discussion Board

Sodium Fluoride and Tooth Decay?

SunriseSunset - 15-11-2015 at 09:29

This kinda boggles my mind a bit.. Why on earth would there be tablets (meant for oral ingestion) of sodium fluoride for treating tooth decay?



Like, how does that work? lol I can't seem to find any science backing direct application of sodium fluoride helping tooth decay. i've heard claims from very old studies, but never actual scientific explanations.

Based on what I know, fluoride ion attacks oxygen so severely that it eats through glass. Enamel is composed of Calcium Phosphate.

SunriseSunset - 15-11-2015 at 09:34

Sodium Fluoride is not intensely water-soluble, but it is to a small enough degree. However, Calcium Fluoride is completely insoluble. So I hypothesize for example, that if you were to continually add NaF to water that has CaCl2 dissolved. You would continually precipitate Calcium Fluoride. I'm going out on a limb here but perhaps it's worth discussion. It might be a good idea to start buying fluoride free toothpaste and spring water from now on. There's a lot of bad rumors going around.

deltaH - 15-11-2015 at 09:39

The mineral component of teeth is hydroxyapatite, Ca5(PO4)3(OH). Note the hydroxyl groups. Those hydroxyl groups can be substituted by other small anions, for example, fluoride, resulting in the formation of fluorapatite, Ca5(PO4)3F.

Hydroxyapatite is susceptible to attack by acids released by bacteria, but fluorapatite is more resistant. Ingesting small amounts of fluoride and exposing the surface of teeth fluoridates them to some degree imparting some measure of protection against bacterial acids.

At least that is what I've been taught ;)



MolecularWorld - 15-11-2015 at 09:42

I haven't done any medical research, but I also think it has to do with the insolubility of calcium fluoride. I took those tablets for a short time when I was younger and, like toothpaste and mouthwash, they weren't meant to be swallowed, just chewed and spat out. I believe a layer of calcium fluoride is supposed to form on teeth to prevent acid erosion.

Edit: deltaH hit enter before me.

[Edited on 15-11-2015 by MolecularWorld]

BromicAcid - 15-11-2015 at 09:47

Here is another photo of the pills along with a brand name:

http://www.pharmer.org/images/foreign/sodium-fluoride-naf

There is plenty of good research out there (search Google scholar and prepare to be inn undated) and an equal amount of unverified quackery along with a few papers that are appropriately skeptical on the benefits and harm of the fluoride ion. Fluoride is toxic, no one will doubt that but it apparently does have therapeutic applications. However, it was my understanding as a layman that the application only had to be done superficially to help with dental carries. That would make me wonder why a pill form would be available. Unfortunately in my exhaustive 5 minutes of searching I came up empty handed.

I had read a book some time ago that discussed how citizens are being purposely poisoned by fluoride by the government around the world. The purpose? Because the aluminum industry produces too much fluoride and the only way to dispose of it is to put it in our water.

SunriseSunset - 15-11-2015 at 09:54

Quote: Originally posted by deltaH  
The mineral component of teeth is hydroxyapatite, Ca5(PO4)3(OH). Note the hydroxyl groups. Those hydroxyl groups can be substituted by other small anions, for example, fluoride, resulting in the formation of fluorapatite, Ca5(PO4)3F.

Hydroxyapatite is susceptible to attack by acids released by bacteria, but fluorapatite is more resistant. Ingesting small amounts of fluoride and exposing the surface of teeth fluoridates them to some degree imparting some measure of protection against bacterial acids.

At least that is what I've been taught ;)


This is the exact type of answer I was looking for! :]

Boffis - 15-11-2015 at 10:02

The reason for fluoride in tooth products is that the outer layer of teeth (the enamel) is composed of hydroxylapatite and it is more susceptable to acid attack than fluorapatite. I presume therefore that the idea is that there is anion exchange F- for OH-.

I am surprised that there would be much exchange as apatites are very stable particularly the fluoroapatite and most mineral apatites are the fluoride dominated member.