Dental fluorosis

Dental fluorosis is a hypomineralization of tooth enamel produced by the chronic ingestion of excessive amounts of fluoride during the period when unerupted teeth are developing. Normal mineralization of permanent teeth, other than third molars, occurs from about the time of birth until about six years of age. After that time, teeth (except third molars) are mineralized to such an extent that they cannot be affected by fluorosis. Nor is it possible after that time to diminish any existing fluorosis by lowering the consumption of ingested fluoride.

The intensity of fluorosis ranges from barely noticeable, whitish flecks or striations that affect only a small portion of the enamel to unsightly confluent pitting of the entire enamel surface with dark brown or black staining. Teeth affected by the mildest degrees of fluorosis generally are not cosmetically compromised and are highly resistant to developing dental decay. Although primary teeth may be affected by dental fluorosis, the condition tends to affect permanent teeth more than primary teeth.

Various indexes or classification systems have been used in surveys to measure the presence and severity of enamel fluorosis. Most indexes score fluorosis according to various scales that range from absent to severe. The index developed by H. Trendley Dean has been used since 1942 and permits important historical comparisons.

Epidemiologic studies done in the 1930s and 1940s of the relation between fluoride concentration in water and dental fluorosis showed that about 10 to 15 percent of persons born and reared in communities with about one part fluoride per million parts of water (ppm) in drinking water had signs of mild forms of fluorosis. When water fluoridation began to be implemented in the United States in 1945, it was the only source of additional ingested fluoride other than that which occurred naturally in some foods and beverages, such as seafood and tea. Since then, many additional sources of fluoride have become available, such as dietary fluoride supplements prescribed as an alternative source of fluoride for areas with fluoridedeficient drinking water, various fluoride solutions, gels and varnishes for professional application, fluoride toothpastes—which currently comprise nearly all toothpaste sales—and fluoride mouth rinses. The use and misuse of these products has led to increased ingestion of fluoride by young children. Consequently, the prevalence, and to a lesser extent, the severity of dental fluorosis has been shown in recent surveys to have increased in both fluoridated and unfluoridated communities. Epidemiologic surveys have shown strong associations between fluorosis and consumption of water with higher than optimal water fluoride concentrations, early use of fluoride toothpastes, use of dietary fluoride supplements, and prolonged use of infant formula in the form of powdered concentrate.

To reduce the risk of developing dental fluorosis, toothbrushing by young children should be supervised closely. They should use only a dab or pea-sized quantity of toothpaste on a child-sized toothbrush and be instructed to spit out thoroughly after brushing. Dietary fluoride supplements should not be prescribed for children who drink fluoridated water. In fluoridated communities, parents who wish to give their children formula beyond the age of one year should use ready-to-feed varieties or dilute powdered concentrate mixed in bottled water with a low-fluoride concentration.

Fluorosis may be tested by bleaching affected teeth, sometimes accompanied by applying various remineralizing agents. Severe fluorosis may be treated cosmetically by bonding various facings on affected teeth.

(SEE ALSO: Community Water Fluoridation; Oral Health)

Bibliography

Dean, H. T. (1942). "The Investigation of Physiological Effects by the Epidemiological Method." In Fluorine and Dental Health, ed. F. R. Moulton. Washington, DC: American Association for the Advancement of Science.

Pendrys, D.; Katz, R.; and Morse, D. (1996). "Risk Factors For Enamel Fluorosis in a Nonfluoridated Population." American Journal of Epidemiology 143:808–815.

Pendrys, D. G., and Katz, R. V. (1998). "Risk Factors for Enamel Fluorosis in Optimally Fluoridated Children Born after the U.S. Manufacturers' Decision to Reduce the Fluoride Concentration of Infant Formula." American Journal of Epidemiology 148:967–974.

— HERSCHEL S. HOROWITZ

A mild case of dental fluorosis (the white streaks on the subject's upper right central incisor) observed in dental practice

Dental fluorosis is a health condition caused by a child receiving too much fluoride during tooth development. The critical period of exposure is between 1 and 4 years old; children over age 8 are not at risk.^[1] In its mild form, which is the most common, fluorosis appears as tiny white streaks or specks that are often unnoticeable. In its severe form it is characterized by black and brown stains, as well as cracking and pitting of the teeth.^[2]

The severity of dental fluorosis depends on the amount of fluoride exposure, the age of the child, individual response, and nutritional and other factors.^[1] Although water fluoridation can cause fluorosis, most of this is mild and not usually of aesthetic concern.^[3] 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.^[4]

Contents 1 Physiology 2 Dean's Index 3 Prevalence 4 American Dental Association advisory 5 Treatment 6 References 7 External links

Physiology

Dental fluorosis occurs because of the excessive intake of fluoride either through fluoride in the water supply, naturally occurring or added to it; or through other sources. The damage in tooth development occurs between the ages of 3 months to 8 years, from the overexposure to fluoride. Teeth are generally composed of hydroxyapatite and carbonated hydroxyapatite; when fluoride is present, fluorapatite is created. Excessive fluoride can cause white spots, and in severe cases, brown stains or pitting or mottling of enamel. Fluorosis cannot occur once the tooth has erupted into the oral cavity. At this point, fluorapatite is beneficial because it is more resistant to dissolution by acids (demineralization). Although it is usually the permanent teeth which are affected, occasionally the primary teeth may be involved.

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.

Dean's Index

H.T. Dean's fluorosis index was developed in 1942 and is currently the most universally accepted classification system. An individual's fluorosis score is based on the most severe form of fluorosis found on two or more teeth.^[5]

Dean's Index

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

Prevalence

As of 2005^[update] surveys conducted by the National Institute of Dental Research in the USA between 1986 and 1987^[6] and by the Center of Disease Control between 1999 and 2002^[7] are the only national sources of data concerning the prevalence of dental fluorosis.

NIDR and CDC findings

Deans Index	1987	2002
Questionable fluorosis	17%	11.8%
Very mild fluorosis		19%
Mild fluorosis	4%	5.83%
Moderate fluorosis	1%	0.59%
Severe fluorosis	0.3%
Total	22.3%	37.2%

The Center of 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 of more than 1ppm (part per million), and in children who have a poor intake of calcium.

Dietary reference intakes for fluoride^[6]

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 (142)	3.0	10
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 rate of 1ppm, it is necessary to consume one litre of water in order to take in 1 mg of fluoride. It is 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. Coal burning can pollute air with fluoride: indoor air with approximately 60 µg F/m³ and drinking water with 3.6 mg F/L are similarly toxic to developing permanent teeth.^[8]

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 began recommending to parents that infants from 0 through 12 months of age should have their formula prepared with water that is fluoride-free, or contains low levels of fluoride to reduce the risk of fluorosis.^[9]

Treatment

Before and after porcelain laminate veneers

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 treatment modalities. Generally speaking, bleaching and microabrasion are used for superficial staining, whereas the conservative restorations are used for more unaesthetic situations.

References

1. ^ ^{a b} 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. http://medicinaoral.com/medoralfree01/v14i2/medoralv14i2p103.pdf. 
2. ^ "Enamel fluorosis". American Academy of Pediatric Dentistry. http://www.aapd.org/publications/brochures/fluorosis.asp. Retrieved 2009-02-04. 
3. ^ 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).  The full report is at: "A systematic review of the efficacy and safety of fluoridation" (PDF). Australian National Health and Medical Research Council. 2007. http://www.nhmrc.gov.au/PUBLICATIONS/synopses/_files/eh41.pdf. Retrieved 2008-12-09. 
4. ^ 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. http://www.who.int/water_sanitation_health/publications/fluoride_drinking_water_full.pdf. Retrieved 2009-01-24. 
5. ^ (PDF) Fluoridation Facts. American Dental Association. 2005. pp. 28–29. http://web.archive.org/web/20070307065553/http://www.ada.org.au/media/Fluoridenow/Documents/AmDA+fluoridation_factsRO.pdf. 
6. ^ ^{a b} (PDF) Fluoridation Facts. American Dental Association. 2005. p. 29. http://web.archive.org/web/20070307065553/http://www.ada.org.au/media/Fluoridenow/Documents/AmDA+fluoridation_factsRO.pdf. 
7. ^ "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. http://www.cdc.gov/mmwr/preview/mmwrhtml/ss5403a1.htm#tab23. Retrieved 2006-10-29. 
8. ^ Ruan JP, Bårdsen A, Astrøm AN, Huang RZ, Wang ZL, Bjorvatn K (2007). "Dental fluorosis in children in areas with fluoride-polluted air, high-fluoride water, and low-fluoride water as well as low-fluoride air: a study of deciduous and permanent teeth in the Shaanxi province, China". Acta Odontol. Scand. 65 (2): 65–71. doi:10.1080/00016350600931217. PMID 17453423. 
9. ^ What is the ADA’s interim guidance on infant formula and fluoride? American Dental Association Website accessed May 28, 2008 http://www.ada.org/public/topics/fluoride/infantsformula_faq.asp#2

External links

• What is fluorosis? has images of very mild, mild, and moderate dental fluorosis.

v • d • e Tooth disease (K00-K05, 520-525) Developmental/ tooth abnormality Quantity Anodontia/Hypodontia · Hyperdontia Abnormalities of size and form Concrescence · Fusion · Gemination · Dens evaginatus/Talon cusp · Dens invaginatus · Enamel pearl · Macrodontia · Microdontia · Taurodontism Disturbances in formation Dilaceration · Regional odontodysplasia · Turner's hypoplasia Other hereditary disturbances in structure Amelogenesis imperfecta · Dentinogenesis imperfecta · Dentin dysplasia Acquired Dental caries · Attrition · Abrasion · Erosion tooth resorption (External resorption, Internal resorption, Root resorption) Pulpitis · Periapical abscess · Fluorosis · Toothache bone cyst (Dentigerous cyst, Calcifying odontogenic cyst, Glandular odontogenic cyst) Alignment Malocclusion see also odontogenic tumors

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