Fluoride therapy
Encyclopedia
Fluoride therapy is the delivery of fluoride
to the teeth topically or systemically in order to prevent tooth decay (dental caries
) which results in cavities. Most commonly, fluoride is applied topically to the teeth using gels, varnishes, toothpaste
/dentifrices
or mouth rinse
. Systemic delivery involves fluoride supplementation using water, salt, tablets or drops which are swallowed. Tablets or drops are rarely used where public water supplies are fluoridated
.
effect on the plaque
fluid. Fluoride combats the decay primarily by the formation fluorapatite
via remineralization of enamel. The fluoride ions reduce the rate of tooth enamel demineralization, and increase the rate of remineralization
of the early stages of cavities. Fluoride exerts its major effect by this demineralization and remineralization cycle. Fluoride also affects the physiology of dental bacteria, although its effect on bacterial growth
does not seem to be relevant to cavity prevention. Fluoride has minimal effect on cavities after it is swallowed. Technically, fluoride does not prevent cavities but rather controls the rate at which they develop. Although fluoride is the only well-documented agent with this property, it has been suggested that also adding some calcium
to the water would reduce cavities further.
organizations. As mentioned, fluoride primarily only helps teeth when it is in the mouth. After it is swallowed, it has minimal effect.
A 2000 systematic review
of water fluoridation's effectiveness found that fluoridation was associated with a decreased proportion of children with cavities (the median of mean decreases was 14.6%, the range â5% to 64%), and with a decrease in decayed, missing, and filled primary teeth (the median of mean decreases was 2.25 teeth, the range 0.5 to 4.4 teeth). A more comprehensive 2007 review which used the 2000 review for its water fluoridation efficacy conclusions affirmed this result.
Prescription strength fluoride toothpaste generally contains 1.1% (4,950 ppm) sodium fluoride toothpaste. This type of toothpaste is used in the same manner as regular toothpaste. It is well established that 1.1% sodium fluoride is safe and effective as a preventive of caries. This prescription dental cream is used up to three times daily in place of regular toothpaste.
is sodium fluoride. Over-the-counter solutions of 0.05% sodium fluoride (225 ppm fluoride) for daily rinsing are available for use. Fluoride at this concentration is not strong enough for people at high risk for cavities.
Prescription mouth rinses are more effective for those at high risk for caries, but are usually counterindicated for children, especially in areas with fluoridated drinking water. However, in areas without fluoridated drinking water, these rinses are sometimes prescribed for children.
The gel or foam is applied through the use of a mouth tray, which contains the product. The tray is held in the mouth by biting. Application generally takes about four minutes, and patients should not rinse, eat, smoke, or drink for at least 30 minutes after application.
Some gels are made for home application, and are used in a manner similar to toothpaste. The concentration of fluoride in these gels is much lower than in professional products.
An imprint of a person's teeth can be made by a dentist, who then uses that to make well fitting trays to put over their teeth. The patient can then use this to hold a fluoride treatment against their teeth overnight.
has practical advantages over gels in ease of application, a non-offensive taste, and use of smaller amounts of fluoride than required for gel applications. Varnish is intended for the same group of patients as the gels and foams. There is also no published evidence as of yet that indicates that professionally applied fluoride varnish is a risk factor for enamel fluorosis
. The varnish is applied with a brush and sets within seconds.
.
and death, but the amounts of fluoride amount to several ounces for an adult. Chronic intake and topical exposure may cause dental fluorosis
, and excess systematic exposure can lead to systemic effects such as skeletal fluorosis
. Young children are at risk for receiving excess fluoride, and the ADA has recently issued an interim guidance on their fluoride consumption.
Most fluorosis is mild and cosmetic, but the chance of more severe fluorosis increases with exposure. A recent report by National Research Council (NRC) states that severe dental fluorosis can be considered a "toxic effect" which increases the prevalence of caries (106), but fluorosis this severe is not expected with the normal use of fluoride therapy.
Fluoride
Fluoride is the anion Fâ, the reduced form of fluorine when as an ion and when bonded to another element. Both organofluorine compounds and inorganic fluorine containing compounds are called fluorides. Fluoride, like other halides, is a monovalent ion . Its compounds often have properties that are...
to the teeth topically or systemically in order to prevent tooth decay (dental caries
Dental caries
Dental caries, also known as tooth decay or a cavity, is an irreversible infection usually bacterial in origin that causes demineralization of the hard tissues and destruction of the organic matter of the tooth, usually by production of acid by hydrolysis of the food debris accumulated on the...
) which results in cavities. Most commonly, fluoride is applied topically to the teeth using gels, varnishes, toothpaste
Toothpaste
Toothpaste is a paste or gel dentifrice used with a toothbrush as an accessory to clean and maintain the aesthetics and health of teeth. Toothpaste is used to promote oral hygiene: it serves as an abrasive that aids in removing the dental plaque and food from the teeth, assists in suppressing...
/dentifrices
Toothpaste
Toothpaste is a paste or gel dentifrice used with a toothbrush as an accessory to clean and maintain the aesthetics and health of teeth. Toothpaste is used to promote oral hygiene: it serves as an abrasive that aids in removing the dental plaque and food from the teeth, assists in suppressing...
or mouth rinse
Mouthwash
Mouthwash or mouth rinse is a product used to enhance oral hygiene. Some manufacturers of mouthwash claim that antiseptic and anti-plaque mouth rinse kill the bacterial plaque causing cavities, gingivitis, and bad breath. Anti-cavity mouth rinse uses fluoride to protect against tooth decay...
. Systemic delivery involves fluoride supplementation using water, salt, tablets or drops which are swallowed. Tablets or drops are rarely used where public water supplies are fluoridated
Water fluoridation
Water fluoridation is the controlled addition of fluoride to a public water supply to reduce tooth decay. Fluoridated water has fluoride at a level that is effective for preventing cavities; this can occur naturally or by adding fluoride...
.
Benefits
Fluoridation is widely, but not universally, accepted by dentists as being useful. The U.S. Center for Disease Control lists water fluoridation as one of the "ten greatest public health achievements of the 20th century." It is therefore understandable that fluoride therapy would be commonly practiced and in many modalities. Many types of fluoride therapies are known, ranging from at-home therapies (use of fluoridated toothpaste) to professionally administered, such as topical fluorides provided by dental offices, to publicly sponsored fluoridation of water or other commonly ingested materials such as salt. At-home therapies can be further divided into over-the-counter (OTC) and prescription strengths. The fluoride therapies, whether OTC or PATF, are categorized by application â dentifrices, mouthrinses, gels/ foams, varnishes, dietary fluoride supplements, and water fluoridation.Mechanism
All fluoridation methods provide low concentrations of fluoride ions in saliva, thus exerting a topicalTopical
In medicine, a topical medication is applied to body surfaces such as the skin or mucous membranes such as the vagina, anus, throat, eyes and ears.Many topical medications are epicutaneous, meaning that they are applied directly to the skin...
effect on the plaque
Dental plaque
Dental plaque is a biofilm, usually a pale yellow, that develops naturally on the teeth. Like any biofilm, dental plaque is formed by colonizing bacteria trying to attach themselves to a smooth surface...
fluid. Fluoride combats the decay primarily by the formation fluorapatite
Fluorapatite
Fluorapatite, often with the alternate spelling of fluoroapatite, is a mineral with the formula Ca53F . Fluorapatite is a hard crystalline solid. Although samples can have various color , the pure mineral is colorless as expected for a material lacking transition metals...
via remineralization of enamel. The fluoride ions reduce the rate of tooth enamel demineralization, and increase the rate of remineralization
Remineralisation of teeth
Remineralisation of teeth is a process in which minerals are returned to the molecular structure of the tooth itself. Teeth are porous allowing fluids and demineralisation beneath the surface of the tooth. When demineralised, these pores become larger...
of the early stages of cavities. Fluoride exerts its major effect by this demineralization and remineralization cycle. Fluoride also affects the physiology of dental bacteria, although its effect on bacterial growth
Bacterial growth
250px|right|thumb|Growth is shown as L = log where numbers is the number of colony forming units per ml, versus T Bacterial growth is the division of one bacterium into two daughter cells in a process called binary fission. Providing no mutational event occurs the resulting daughter cells are...
does not seem to be relevant to cavity prevention. Fluoride has minimal effect on cavities after it is swallowed. Technically, fluoride does not prevent cavities but rather controls the rate at which they develop. Although fluoride is the only well-documented agent with this property, it has been suggested that also adding some calcium
Calcium
Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust...
to the water would reduce cavities further.
Water fluoridation
Water fluoridation is the controlled addition of fluoride to a public water supply in order to reduce tooth decay. Its use in the U.S. began in the 1940s, following studies of children in a region where water is naturally fluoridated. It is now used for about two-thirds of the U.S. population on public water systems and for about 5.7% of people worldwide. Although the best available evidence shows no association with adverse effects other than fluorosis, most of which is mild, water fluoridation has been contentious for ethical, safety, and efficacy reasons, and opposition to water fluoridation exists despite its support by public healthPublic health
Public health is "the science and art of preventing disease, prolonging life and promoting health through the organized efforts and informed choices of society, organizations, public and private, communities and individuals" . It is concerned with threats to health based on population health...
organizations. As mentioned, fluoride primarily only helps teeth when it is in the mouth. After it is swallowed, it has minimal effect.
A 2000 systematic review
Systematic review
A systematic review is a literature review focused on a research question that tries to identify, appraise, select and synthesize all high quality research evidence relevant to that question. Systematic reviews of high-quality randomized controlled trials are crucial to evidence-based medicine...
of water fluoridation's effectiveness found that fluoridation was associated with a decreased proportion of children with cavities (the median of mean decreases was 14.6%, the range â5% to 64%), and with a decrease in decayed, missing, and filled primary teeth (the median of mean decreases was 2.25 teeth, the range 0.5 to 4.4 teeth). A more comprehensive 2007 review which used the 2000 review for its water fluoridation efficacy conclusions affirmed this result.
Toothpaste
Most toothpaste today contains 0.32% (1450 ppm) fluoride, usually in the form of sodium fluoride or sodium monofluorophosphate (MFP); 100 g of toothpaste containing 0.76 g MFP equates to 0.1 g fluoride.Prescription strength fluoride toothpaste generally contains 1.1% (4,950 ppm) sodium fluoride toothpaste. This type of toothpaste is used in the same manner as regular toothpaste. It is well established that 1.1% sodium fluoride is safe and effective as a preventive of caries. This prescription dental cream is used up to three times daily in place of regular toothpaste.
Mouth rinses
The most common fluoride compound used in mouth rinseMouthwash
Mouthwash or mouth rinse is a product used to enhance oral hygiene. Some manufacturers of mouthwash claim that antiseptic and anti-plaque mouth rinse kill the bacterial plaque causing cavities, gingivitis, and bad breath. Anti-cavity mouth rinse uses fluoride to protect against tooth decay...
is sodium fluoride. Over-the-counter solutions of 0.05% sodium fluoride (225 ppm fluoride) for daily rinsing are available for use. Fluoride at this concentration is not strong enough for people at high risk for cavities.
Prescription mouth rinses are more effective for those at high risk for caries, but are usually counterindicated for children, especially in areas with fluoridated drinking water. However, in areas without fluoridated drinking water, these rinses are sometimes prescribed for children.
Gels/foams
Gels and foams are used for individuals who are at high risk for caries, orthodontic patients, patients undergoing head and neck radiation, patients with decreased salivary flow, and children whose permanent molars should, but cannot, be sealed.The gel or foam is applied through the use of a mouth tray, which contains the product. The tray is held in the mouth by biting. Application generally takes about four minutes, and patients should not rinse, eat, smoke, or drink for at least 30 minutes after application.
Some gels are made for home application, and are used in a manner similar to toothpaste. The concentration of fluoride in these gels is much lower than in professional products.
An imprint of a person's teeth can be made by a dentist, who then uses that to make well fitting trays to put over their teeth. The patient can then use this to hold a fluoride treatment against their teeth overnight.
Varnish
Fluoride varnishFluoride varnish
Fluoride varnish is a highly concentrated form of fluoride which is applied to the tooth's surface, by a dentist, dental hygienist or other health care professional, as a type of topical fluoride therapy. It is not a permanent varnish but due to its adherent nature it is able to stay in contact...
has practical advantages over gels in ease of application, a non-offensive taste, and use of smaller amounts of fluoride than required for gel applications. Varnish is intended for the same group of patients as the gels and foams. There is also no published evidence as of yet that indicates that professionally applied fluoride varnish is a risk factor for enamel fluorosis
Dental fluorosis
Dental fluorosis 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 between the ages of 3 months and 8 years. In its mild forms , fluorosis often appears as unnoticeable,...
. The varnish is applied with a brush and sets within seconds.
Slow-release devices
Devices that slowly release fluoride can be implanted on the surface of a tooth, typically on the side of a molar where it is not visible and does not interfere with eating. The two main types are copolymer membrane and glass bead. These devices are effective in raising fluoride concentrations and in preventing cavities, but they have problems with retention rates, that is, the devices fall off too often.Dietary supplements
Dietary fluoride supplements in the form of tablets, lozenges, or liquids (including fluoride-vitamin preparations) are used primarily for children in areas without fluoridated drinking water. The evidence supporting the effectiveness of this treatment for primary teeth is weak. The supplements prevent cavities in permanent teeth. A significant side effect is mild to moderate dental fluorosisDental fluorosis
Dental fluorosis 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 between the ages of 3 months and 8 years. In its mild forms , fluorosis often appears as unnoticeable,...
.
Indications for fluoride therapy
The individual's risk factors and the reason for treatment will determine which method of fluoride delivery is used. Consult with a dentist before starting any treatment.- white spotsDental cariesDental caries, also known as tooth decay or a cavity, is an irreversible infection usually bacterial in origin that causes demineralization of the hard tissues and destruction of the organic matter of the tooth, usually by production of acid by hydrolysis of the food debris accumulated on the...
- Moderate to high risk patients for developing decay
- Active decay
- Orthodontic treatmentOrthodonticsOrthodontics, orthodontia, or orthodonture is the first specialty of dentistry that is concerned with the study and treatment of malocclusions , which may be a result of tooth irregularity, disproportionate jaw relationships, or both...
- Additional protection if necessary for children in areas without fluoridated drinking water
- To reduce tooth sensitivity
- Protect root surface
- Decreased salivary flow
- Institutionalized patients
Health risks
Consumption of large amounts of fluoride can lead to fluoride poisoningFluoride poisoning
In high concentrations, soluble fluoride salts are toxic and skin or eye contact with high concentrations of many fluoride salts is dangerous. Referring to a common salt of fluoride, sodium fluoride , the lethal dose for most adult humans is estimated at 5 to 10 g...
and death, but the amounts of fluoride amount to several ounces for an adult. Chronic intake and topical exposure may cause dental fluorosis
Dental fluorosis
Dental fluorosis 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 between the ages of 3 months and 8 years. In its mild forms , fluorosis often appears as unnoticeable,...
, and excess systematic exposure can lead to systemic effects such as skeletal fluorosis
Skeletal fluorosis
Skeletal fluorosis is a bone disease caused by excessive consumption of fluoride. In advanced cases, skeletal fluorosis causes pain and damage to bones and joints.-Forms:...
. Young children are at risk for receiving excess fluoride, and the ADA has recently issued an interim guidance on their fluoride consumption.
Overdose
In 1974 a 3-year old child swallowed 45 milliliters of 2% fluoride solution, estimated to be triple the fatal amount, and then died. The fluoride was administered during his first visit to the dentist, and the dental office was later found liable for the death.Fluorosis
- See main article Dental fluorosisDental fluorosisDental fluorosis 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 between the ages of 3 months and 8 years. In its mild forms , fluorosis often appears as unnoticeable,...
.
Most fluorosis is mild and cosmetic, but the chance of more severe fluorosis increases with exposure. A recent report by National Research Council (NRC) states that severe dental fluorosis can be considered a "toxic effect" which increases the prevalence of caries (106), but fluorosis this severe is not expected with the normal use of fluoride therapy.
Fluoride conversion chart
| APF (10)(%)(1000) | ppm |
|---|---|
| 1.0% | 10,000 |
| 1.23% | 12,300 |
| NaF (4.5)(%)(1000) | ppm |
| 0.05% | 225 |
| 0.20% | 900 |
| 0.44% | 1,980 |
| 1.0% | 4,500 |
| 1.1% | 4,950 |
| 2.0% | 9,000 |
| 5.0% | 22,500 |
| SnF2 (2.4)(%)(1000) | ppm |
| 0.40% | 960 |
| 0.63% | 1,512 |
Further reading
- Committee on Fluoride in Drinking Water, National Research Council. (2006). Fluoride in Drinking Water: A Scientific Review of EPA's Standards. National Academies Press.
- government guidelines
- Fluoride History History of fluoride therapy including early patents
- Clark CD. Appropriate use of fluorides in the 1990s. J Canad Dent Assoc. 1993;59:272-279.
- Hawkins R, Locker D, Noble J, Kay EJ. Prevention. Part 7: Professionally applied topical fluorides for caries prevention. British Dental J. 2003: Vol. 195, No 6: 313-317.
- Moran R, Saemundsson S. Fluoride Varnish: An alternative to traditional topical fluoride therapy. Department of Pediatric Dentistry, University of North Carolina 1996
- Stookey GK. Review of fluorosis risk of self-applied topical fluorides: dentifrices, mouthrinses and gels. Community Dent Oral Epidemiol. 1994;22:282-286