Dental Biotech: Synthesizing Fluorapatite

[bomba923]

Some background information first:

*Hydroxyapatite (i.e., Ca₅[(PO₄)₃OH]) comprises 97-98% of human tooth enamel. It will demineralize at pH 5.5.

*Fluoride ions are usually added to drinking water and are found in fluoride toothpastes (commonly via NaF).
According to Wikipedia,

Fluoride ions can replace hydroxide ions in hydroxyapatite (Ca₅[(PO₄)₃OH]), forming fluorapatite (Ca₅[(PO₄)₃F]), which is more chemically stable and dissolves at pH 4.5. This is generally believed to lead to fewer cavities, since stronger acids are needed to attack the tooth enamel.

According to the http://www.uvm.edu/~swgordon/131-01/131web/caseymorley/discussion.html ,

The difference in solubility products between hydroxyapatite and fluorapatite is important to consider when examining their resistance to cavities. As discussed in demineralization, hydroxyapatite is more dissociated in equilibrium than fluorapatite, which assumingly allows acids to penetrate the crystal structure more easily.
Perhaps the most important property of fluorapatite in its resistance to cavities is the F^- itself. When F^- ions are released, they help kill cavity-causing bacteria.

Sounds wonderful
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Now here is my question:

-What if the formation of fluorapatite (for our teeth) did not require drinking water, and fluoride toothpaste? What if...say, we could synthesize fluorapatite ourselves (biologically speaking)?
-Is there a genetic basis for the synthesis of hydroxyapatite?→Can we alter this...to produce fluorapatite instead ?

(*I am not certain, however, as to where the body might 'obtain' these fluoride anions...early on...(But I like biotechnology))

 

[Moonbear]

We'd still need to get fluoride from somewhere.

But, related to your question, I just came across this article today saying that you can also get too much fluoride, and it can damage teeth and bones!

http://apnews.excite.com/article/20060322/D8GGNC6O3.html

WASHINGTON (AP) - The high levels of fluoride that occur naturally in some drinking water can cause tooth and bone damage and should be reduced, the National Research Council said Wednesday.

The study did not analyze the benefits or risks of adding fluoride to drinking water. Instead it looked at the current maximum limit of 4 milligrams per liter. Approximately 200,000 people live in communities where that level occurs naturally in water.

 

[DocToxyn]

I believe that the hydroxyapatite found in enamel is also the same that is found in bone. It may not possible to modify one without the other thus there may be some broader-reaching toxicities associated with this application of fluoride, especially when you are talking about incorporating it into developing systems. Your teeth may be better off, but the damage that was incurred during bone development way outweighs it. Evolution may have avoided/eliminated direct exposure to fluoride during these sensitive time periods and instead opted for later incorporation via exposure of the external compartment. Of course, this is purely hypothetical.