Enamel fluorosis levels

In general, moderate and severe fluorosis is rare. However, mild fluorosis has been detected at significant levels, for example, in 26% of subjects in one recent study [93]. However, the mildness of the fluorosis detected is associated with only very slight changes in the appearance of the teeth, which suggests that, even at these levels, it is not a major public health problem. Nonetheless, it is appropriate to ensure that parents or guardians of children continue to receive sound advice on safe levels of fluoride for those in their care to be exposed to and, since the cariostatic effect of fluoride is known to occur well after enamel formation during tooth development, treatment to reduce caries should concentrate on those measures that carry the lowest possible risks of fluorosis [91]. 

Fig. 2. Teeth demonstrating fluorosis. A high level of dietary fluoride has resulted in much of the enamel becoming opaque in patches, giving a mottled appearance. (Reprinted with permission from [48]. Copyright 2002 Mosby International Limited.) (See Colour Plate Section at the end of this book.)...

Ingestion > inhalation. At low levels mottling of tooth enamel. At high levels fluorosis—includes wide variety of health problems such as hyperparathyroidism, calcification of soft tissues, interference with collagen formation, severe skeletal deformity. 

At low-level concentrations, fluoride can reduce the risk of dental cavities. Exposure to somewhat higher amounts of fluoride can cause dental fluorosis, which, in its mildest form, can result in the discoloration of teeth. Severe dental fluorosis produces pitting and alteration of tooth enamel. Higher intake of fluoride, taken over a long period of time, can result in changes to bone and in a condition known as skeletal fluorosis. The effects of skeletal fluorosis include joint pain, restriction of mobility, and a possible increase in the risk of some bone fractures. 

Fluorine is a cumulative poison hence, chronic fluoride toxicity, known as fluorosis, may not be noticed for sometime. The enamel of the teeth will likely lose luster and become chalky and mottled when one of the following conditions prevails (1) when the fluoride content of the drinking water exceeds 2.5 ppm (2) when the amount of fluorine ingested exceeds 30 to 40 ppm of the dry matter of the diet or (3) when a person consumes (in food and water) fluorine in excess of 20 mg/day over an extended period of time. The degree of mottling depends upon the level of fluorine intake and individual susceptibility. Mottling of teeth in children heis been observed at fluoride concentrations in the diet and drinking water of 2 to 8 ppm. 

Fig. F-37. Fluorosis of human teeth, showing characteristic change in the enamel—loss of luster, and a chalky mottled appearance. This occurred in a lifetime resident of a community in which the drinking water naturally contained flouride at concentrations 2 to 3 times greater than the level considered optimal. (Courtesy, Department of Health and Human Services, Public Health Service, National Institute of Health, Bethesda, Md.)...

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