ACTION OF FLUORIDE ON TEETH
It is deposited on the enamel by the formation of a globular deposits of CaF2.
These globules do not dissolve as quickly as expected on their basis of their solubility.
The solubility is attributed to prescence of phosphate and proteins rich surface covering these globules.
The dissolution of fluoride from globules is pH dependent,because phosphate ions are released when they are protonated at low pH.
During a cariogenic challenge, F released from this globules may diffuse into the enamel promoting reformation of apatite.
It is known that the formation of the CaF2 reservoir is increased under acidic compared to neutral condition.
Fluoride from saliva or exogenous sources such as fluoride rinses, gels, varnishes and toothpastes is taken up preferentially by biofilms, lessens the effects of an acidogenic challenge and facilitates remineralization when the resting pH returns to 7.0.
INCREASED CONCENTRATION
Increased concentrations of calcium and phosphate in biofilms, saliva and artificial calcifying fluids, excessive levels of fluoride lead to rapid mineral precipitation on the enamel surface and owing to occlusion of surface porosities communicating with the subsurface leads to white-spots.
INCREASED CONCENTRATION
Increased concentrations of calcium and phosphate in biofilms, saliva and artificial calcifying fluids, excessive levels of fluoride lead to rapid mineral precipitation on the enamel surface and owing to occlusion of surface porosities communicating with the subsurface leads to white-spots.
So that high concentration topical fluoride results in unsightly white opacification of enamel lesions.
High frequency application of low F concentration agents has been considered the most beneficial treatment regime.
journal of de n t i s t r y, 2 0 0 8
Adv Dent Res ,1994
