Owing to the universal presence of fluorides in water, soil and air, it is not surprising that individuals are exposed to various levels of fluoride intake through foods, water, industrial and pharmaceutical products and other sources. Although water-borne fluoride has been said to represent the single largest source of daily intake of fluoride, in some parts of the world, staple diets, particularly high in fluoride may be the main contributor. Since it's a double edged sword, intake of fluoride in a limited range plays a key role in prevention of dental caries. Knowledge of the mechanism by which fluoride promotes caries control is essential for the achievement of the maximum benefits of this element with minimum risk of side effects. Thus, fluoride is still of the utmost importance for preventing dental caries, as well as for modern non- invasive dental caries management.