|Classification and external resources|
A mild case of dental fluorosis (the white streaks on the subject's upper right central incisor) observed in dental practice
Dental fluorosis, also called mottling of tooth enamel, is a developmental disturbance of dental enamel caused by excessive exposure to high concentrations of fluoride during tooth development. The risk of fluoride overexposure occurs at any age but it is higher at younger ages. In its mild forms (which are its most common), fluorosis often appears as unnoticeable, tiny white streaks or specks in the enamel of the tooth. In its most severe form, tooth appearance is marred by discoloration or brown markings. The enamel may be pitted, rough and hard to clean. The spots and stains left by fluorosis are permanent and may darken over time.
Teeth are generally composed of hydroxyapatite and carbonated hydroxyapatite; as the intake of fluoride increases, so does the teeth's composition of fluorapatite. Excessive fluoride can cause white spots and, in severe cases, brown stains, pitting, or mottling of the enamel. A tooth is no longer at risk of fluorosis after eruption into the oral cavity. At this point, fluorapatite is beneficial because it is more resistant to dissolution by acids (demineralization). Although fluorosis usually affects permanent teeth, occasionally the primary teeth may be involved.
Risk factors for dental fluorosis
The most superficial concern in dental fluorosis is aesthetic changes in the permanent dentition (the adult teeth). These changes are prone to occur in children who are excessively exposed to fluoride between 20 and 30 months of age. The critical period of exposure is between 1 and 4 years old, and the child is no longer at risk after 8 years of age. The severity of dental fluorosis depends on the amount of fluoride exposure, the age of the child, individual response, weight, degree of physical activity, nutrition, and bone growth.
Recent studies have shown that fluorosis is associated with oxidative stress on neurons in the brain . This oxidative stress is linked to neurodegeneration as seen in Alzheimer's and other brain disorders.
Many well-known sources of fluoride may contribute to overexposure including dentifrice/fluoridated mouthrinse (which young children may swallow), bottled waters which are not tested for their fluoride content, inappropriate use of fluoride supplements, ingestion of foods especially imported from other countries, and public water fluoridation. The last of these sources is directly or indirectly responsible for 40% of all fluorosis, but the resulting effect due to water fluoridation is largely and typically aesthetic. Severe cases can be caused by exposure to water that is naturally fluoridated to levels well above the recommended levels, or by exposure to other fluoride sources such as brick tea or pollution from high fluoride coal.
The differential diagnosis for this condition may include Turner's hypoplasia (although this is usually more localized), some mild forms of amelogenesis imperfecta, and other environmental enamel defects of diffuse and demarcated opacities.
H.T. Dean's fluorosis index was first published in 1934. The index underwent two changes, appearing in its final form in 1942. This form became the most universally accepted classification system for dental fluorosis. An individual's fluorosis score is based on the most severe form of fluorosis found on two or more teeth.
|Classification||Criteria – description of enamel|
|Normal||Smooth, glossy, pale creamy-white translucent surface|
|Questionable||A few white flecks or white spots|
|Very Mild||Small opaque, paper white areas covering less than 25% of the tooth surface|
|Mild||Opaque white areas covering less than 50% of the tooth surface|
|Moderate||All tooth surfaces affected; marked wear on biting surfaces; brown stain may be present|
|Severe||All tooth surfaces affected; discrete or confluent pitting; brown stain present|
As of 2005[update] surveys conducted by the National Institute of Dental and Craniofacial Research in the USA between 1986 and 1987 and by the Center of Disease Control between 1999 and 2002 are the only national sources of data concerning the prevalence of dental fluorosis.
|Very mild fluorosis||19.85%|
The U.S. Centers for Disease Control found a 9% higher prevalence of dental fluorosis in American children than was found in a similar survey 20 years ago. In addition, the survey provides further evidence that African Americans suffer from higher rates of fluorosis than Caucasian Americans.
The condition is more prevalent in rural areas where drinking water is derived from shallow wells or hand pumps. It is also more likely to occur in areas where the drinking water has a fluoride content greater than 1 ppm (part per million), and in children who have a poor intake of calcium.
|Age group||Reference weight kg (lb)||Adequate intake (mg/day)||Tolerable upper intake (mg/day)|
|Infants 0–6 months||7 (16)||0.01||0.7|
|Infants 7–12 months||9 (20)||0.5||0.9|
|Children 1–3 years||13 (29)||0.7||1.3|
|Children 4–8 years||22 (48)||1.0||2.2|
|Children 9–13 years||40 (88)||2.0||10|
|Boys 14–18 years||64
|Girls 14–18 years||57 (125)||3.0||10|
|Males 19 years and over||76 (166)||4.0||10|
|Females 19 years and over||61 (133)||3.0||10|
If the water supply is fluoridated at the level of 1 ppm, one must consume one litre of water in order to take in 1 mg of fluoride. It is thus improbable a person will receive more than the tolerable upper limit from consuming optimally fluoridated water alone.
Fluoride consumption can exceed the tolerable upper limit when someone drinks a lot of fluoride containing water in combination with other fluoride sources, such as swallowing fluoridated toothpaste, consuming food with a high fluoride content, or consuming fluoride supplements. The use of fluoride supplements as a prevention for tooth decay is rare in areas with water fluoridation, but was recommended by many dentists in the UK until the early 1990s.
Dental fluorosis can be prevented by lowering the amount of fluoride intake to below the tolerable upper limit.
American Dental Association advisory
In November 2006 the American Dental Association published information stating that water fluoridation is safe, effective and healthy; that enamel fluorosis, usually mild and difficult for anyone except a dental health care professional to see, can result from ingesting more than optimal amounts of fluoride in early childhood; that it is safe to use fluoridated water to mix infant formula; and that the probability of babies developing fluorosis can be reduced by using ready-to-feed infant formula or using water low in fluoride to prepare powdered or liquid concentrate formula. They go on to say that the way to get the benefits of fluoride but minimize the risk of fluorosis for a child is to get the right amount of fluoride, not too much and not too little. "Your dentist, pediatrician or family physician can help you determine how to optimize your child’s fluoride intake." 
Dental fluorosis can be cosmetically treated by a dentist. The cost and success can vary significantly depending on the treatment. Tooth bleaching, microabrasion, and conservative composite restorations or porcelain veneers are commonly used treatments. Generally speaking, bleaching and microabrasion are used for superficial staining, whereas the conservative restorations are used for more unaesthetic situations.
- "Enamel fluorosis". American Academy of Pediatric Dentistry. Retrieved 2009-02-04.
- Alvarez JA, Rezende KMPC, Marocho SMS, Alves FBT, Celiberti P, Ciamponi AL (2009). "Dental fluorosis: exposure, prevention and management" (PDF). Med Oral Patol Oral Cir Bucal 14 (2): E103–7. PMID 19179949.
- "Curcumin attenuates neurotoxicity induced by fluoride: An in vivo evidence". Pharmocognosy Magazine.
- United States Environmental Protection Agency (2010). Comment-Response Summary Report for the Peer Review of the Fluoride: Dose-Response Analysis for Non-Cancer Effects Document. Lay summary – EPA (2010).
- Yeung CA (2008). "A systematic review of the efficacy and safety of fluoridation". Evid Based Dent 9 (2): 39–43. doi:10.1038/sj.ebd.6400578. PMID 18584000. Lay summary – NHMRC (2007).
- Fawell J, Bailey K, Chilton J, Dahi E, Fewtrell L, Magara Y (2006). "Environmental occurrence, geochemistry and exposure" (PDF). Fluoride in Drinking-water. World Health Organization. pp. 5–27. ISBN 92-4-156319-2. Retrieved 2009-01-24.
- Fluoridation Facts (PDF). American Dental Association. 2005. pp. 28–29. Archived from the original on March 7, 2007.
- Fluoridation Facts (PDF). American Dental Association. 2005. p. 29. Archived from the original on March 7, 2007.
- "Table 23, Surveillance for Dental Caries, Dental Sealants, Tooth Retention, Edentulism, and Enamel Fluorosis --- United States, 1988--1994 and 1999--2002". Centers for Disease Control and Prevention. 2005. Retrieved 2006-10-29.
- Frequently Asked Questions (FAQ), American Dental Association Website accessed February 4, 2012