Priyanka Purohit, Yashila Jamir, Dinesh Rao & Sunil Panwar

THE action of fluoride ions in humans is a typical example of adouble-edged sword. Fluoride is beneficial in small amounts but larger quantities lead to toxicity. Daily optimum level of fluoride consumption plays an important role in preventing dental caries and enhances the mineral deposition in bone.But fluoride beyond the threshold concentration can cause toxicity. Prolonged and excessive consumption of fluoride in various forms leads to deleterious effects on teeth (dental fluorosis), bone (skeletal fluorosis), and soft tissue (non-skeletal fluorosis).

In the early 1900s,brown mottled enamel was observed byDr Fredrick McKay as a clinical effect of fluoride in Colorado.The stains were known as the ‘Colorado stains’ by local inhabitants. Dr Fredrick McKay further investigated and named these stains ‘Mottled enamel.’

Around the 1920s, Dr Henry Klein found that enamel readily adsorbed fluoride. And so, individuals born in fluoridated environments developed teeth with greater resistance to caries compared to those exposed to fluoride after the eruption.

Research also showed that the presence of fluoride at certain levels in the water supply (1 part per million) resulted in minimum mottling and significantly lower prevalence of dental caries than that experienced in populations not exposed to fluoridated water supply.Hence, the optimal fluoride level recommended by the American Dental Association (ADA) for drinking water is 0.7-1.2ppm.

Fluoride consumption beyond this recommended level leads to a condition known as dental fluorosis. It is a fluoride-induced condition in which enamel development is disrupted. It is observed as white spots or opaque white lines. When the fluoride intake is moderate, brown stains are seen, and at higher concentrations, discrete pitting of the enamel surface is seen…read more on NOPR