Dental fluorosis is a disorder characterized by permanent discoloration and brown markings on the surface of teeth due to excessive exposure to fluorides. It is a developmental disturbance which is caused by incorporation of the excess fluoride ions within the tooth structures. The disorder is caused during the period of development of the dentition (4 months to 9 years of age). Generally teeth affected by dental fluorosis are resistant to dental caries. The amount of tooth surface affected by dental fluorosis depends upon the frequency, duration and severity of fluoride exposure.
The excess of fluoride creates enamel defects leading to formation of less mineralized enamel. This hypomineralized enamel is more porous and has lesser strength compared to normal enamel.
The mild forms of fluorosis are characterized by diffuse white, chalky areas of discoloration. The tooth appears less translucent and lacks the shiny surface of a normal tooth. If present on the front teeth these spots pose an aesthetic problem. The area may be slightly softer than normal enamel.
In moderate cases of dental fluorosis yellow to dark brown spots are seen on most of the teeth. In few cases larger portions of tooth surfaces may be involved. These areas are termed as ‘mottled enamel ‘characterized by zones of soft, hypomineralized enamel.
In very severe cases deep, irregular, brownish pits can be noticed on the tooth surfaces.
Dental fluorosis arises when a child is exposed to an excess of dietary fluoride. Most of the cases the source of fluoride is drinking water. Fluoridated water is generally advised to prevent dental caries. The optimum amount of fluorides is 1ppm (part per million). Water containing higher amounts of fluoride can easily lead to the development of fluorosis in children.
In certain geographic areas the available water is high in fluoride. Since the 20th century, the use of fluoridated water is adopted to minimize dental decay. Few food items such as pickles, cucumber, grape juice and spinach also contain fluorides.
Use of fluoridated toothpastes in early ages or consumption of toothpaste can also lead to excess of fluoride in the body. Children advised to use fluoride tablets or topical supplements to avoid dental decay are also susceptible to fluorosis if they exceed the prescribed amount of the drug.
Prevention of dental fluorosis on larger scale is carried out by defluoridation of the drinking water containing excessive fluorides. Avoidance of fluoridated toothpastes in very young children and optimizing the use of toothpastes in older children. Supervision of children using any fluoride containing products is recommended, as excess of fluorides can lead to fluoride toxicity.
Treatment of dental fluorosis depends upon the extent of tooth involvement.Generally dental fluorosis is only associated with cosmetic problems. In mild cases teeth whitening procedures are carried out. Microabrasion of the teeth and bleaching of the teeth are effective forms of tooth whitening. For the cases which can not be treated by teeth whitening, dental composites are used. The affected areas are excavated and replaced by dental composite restorations. Porcelain veneers can also be used to restore the natural color of the teeth.