Flouride is an element that is essential for the general well being of the body at large, but to be specific it contributes immensely to the dental well being.
How is it important?
Flouride renders the enamel of the teeth more resistant to dissolution under an acid attack, and hence, prevents tooth cavitation.
How does it exert its effects?
Flouride, through many sources (toothpastes, diet, water, salt) gets incorporated into the surface enamel layers of the teeth and forms a structure called Flourhydroxyapatite.
- The Flouride ion replaces the hydroxyl ions and are held by more extensive hydrogen bonding which leads to a stronger structure which is more resistant to acidic dissolution.
The oral fluids that bathe the teeth are saturated with fluorides. Under acidic conditions (after a meal), the outermost mineral layer of the teeth start to dissolve, however, the saturated solution of fluorides present in the saliva/plaque, diffuse into the porous layers, interacting with the basic mineral unit, hydroxyapatite, and forms flourhydroxyapatite, which is more resistant to decay. This process of remineralisation forms a composite, where the surface of the lesion is supersaturated with flourhydroxyapatite and the interior of the lesion is still saturated with hydroxyapatite. The interior of the lesion has the potential to be supersaturated with Flourhydroxyapatite, if minimal concentrations of flouride are maintained in the oral fluids. This can be achieved by the small amounts of flouride through the dentifrices or food.
2. The flouride may also exert its action biologically, by its direct action on the bacterial enzyme enolase which reduces the bacterial acid production or disrupting the bacterial cells by dissociation of HF into H ions and F ions.
In what forms can flouride be utilised?
Flouride can be consumed through regular dietary sources.
Flouride is present in dentifrices and is therefore available as a local reserve around the teeth. The maximum permissible range of Flouride in toothpastes should not be above 1000ppm. There are various types of toothpastes based on their flouride content and therefore the intended action.
Daily Requirements Of Flouride:
The maximum permissible range of flouride intake differs among various age groups. The biological age of a person determines the dental age and the stage of enamel formation of the permanent teeth. Once the enamel formation for the permanent teeth is completed, there is fairly a low risk of developmental disturbances to occur.
Flouride: Double edged sword
Dr. Pooja Chaturvedi 