View Single Post
Mar22-06, 02:12 AM
P: 736
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 University of Vermont,
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
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 produce fluorapatite instead ?

(*I am not certain, however, as to where the body might 'obtain' these fluoride anions...early on...(But I like biotechnology))
Phys.Org News Partner Biology news on
An uphill climb for mountain species?
Brain circuit differences reflect divisions in social status
Extinctions during human era worse than thought