Water fluoridation is the addition of fluoride to a public water supply to reduce tooth decay. Fluoridated water contains fluoride at a level that is effective for preventing cavities; this can occur naturally or by adding fluoride. Although fluoridation can cause dental fluorosiswhich can alter the appearance of developing teeth or
Fluoridating agents fluorosis the differences are mild and usually not considered to be of aesthetic or public health concern.
Drinking water is typically the largest source;  other methods of fluoride therapy fluoridation toothpaste, salt, and The Australian government states that water fluoridation is the most effective way to achieve fluoride exposure that is community-wide.
Public water fluoridation was first practiced in the U. A further 28 countries have water that is naturally fluoridated, though in many of them the fluoride is above the optimal level. Some countries Fluoridating agents communities have discontinued fluoridation, Fluoridating agents others have expanded it.
The goal of water fluoridation is to prevent tooth decay by adjusting the Fluoridating agents of fluoride in public water supplies. The goal of water Fluoridating agents is to prevent a chronic disease whose burdens particularly fall on children and the poor. Health and dental organizations worldwide have endorsed Fluoridating agents safety and effectiveness.
Fluoridation does not affect the appearance, taste, or smell of drinking water. These compounds were Fluoridating agents for their solubilitysafety, availability,
Fluoridating agents low cost. Centers for Disease Control and Prevention developed recommendations for water fluoridation that specify requirements for personnel, reporting, training, inspection, monitoring, surveillance, and actions in case of overfeed, along with technical
Fluoridating agents for each major compound used.
Although fluoride was once considered an essential
Fluoridating agents U. National Research Council has since
Fluoridating agents this designation due to the lack of studies showing it is essential for human growth, though still considering fluoride a "beneficial element" due to its positive impact on oral health.
The AI of fluoride from
Fluoridating agents sources including non-dietary sources is 0. Inthe U. Public Health Service PHS for fluoridation of community water systems, recommended that bottled water
Fluoridating agents limit fluoride in bottled water to no more than 0.
Previous recommendations were based on evaluations fromwhen the U. Fluoridating agents standards are not appropriate for all parts of the world, where fluoride levels might be excessive and fluoride Fluoridating agents be removed from water, and is based on assumptions that have become obsolete with the rise of air conditioning and increased use of soft drinksprocessed foodfluoridated toothpasteand other sources of fluorides.
Fluoride naturally occurring in water can be above, at, or below recommended levels.
Rivers and lakes generally contain fluoride levels less than Fluoridating agents. Because fluoride levels in
Fluoridating agents are usually controlled by Fluoridating agents solubility of fluorite CaF 2high natural fluoride levels are associated with calcium -deficient, alkaline, and soft waters. It can be accomplished by percolating water through granular beds of activated alumina
Fluoridating agents mealbone charor tricalcium phosphate ; by coagulation with alum ; or by precipitation with lime.
Existing evidence suggests that water fluoridation reduces tooth decay. Consistent evidence also suggests that it causes dental fluorosismost of which is mild and not
Fluoridating agents of aesthetic concern.
Reviews have shown that water fluoridation reduces cavities in children. The review found Fluoridating agents the evidence was of moderate quality: Although no major differences between natural and artificial fluoridation were apparent, Fluoridating agents evidence was inadequate for a conclusion about any differences. This did not affect the York conclusions.
Fluoride may also prevent cavities in adults of all ages. Most countries in Europe have experienced substantial declines in cavities without the use of water fluoridation due to the introduction of fluoridated toothpaste in the s and the large use of other fluoride-containing products, including mouthrinse, dietary supplements, and Fluoridating agents applied or prescribed gel, foam, or varnish.
Fluoridating agents still clearly necessary in the U. Fluoride's adverse effects depend on total fluoride dosage Fluoridating agents all sources. At the commonly recommended dosage, the only clear adverse effect is dental fluorosiswhich can alter the appearance of children's teeth during tooth development ; this is mostly mild and is unlikely to represent any real
Fluoridating agents on aesthetic appearance or on public health.
The critical period of exposure is between ages one and four years, with risk ending around Fluoridating agents eight. Here, aesthetic concern is a
Fluoridating agents used in a standardized scale based on what adolescents would find as measured by a study Fluoridating agents British year-olds.
Fluoridation has little effect on risk of bone fracture broken bones ; it may result in slightly lower fracture risk than either excessively high levels of fluoridation or no fluoridation. Fluoride can occur naturally in water in well above recommended levels, which can have several long-term adverse effectsincluding Fluoridating agents fluorosisskeletal fluorosisand weakened bones; water utilities in the developed world reduce fluoride levels to regulated maximum levels in regions where natural levels are high, and the WHO and other groups work with countries and regions in the developing world with naturally excessive fluoride levels to achieve safe levels.
In rare cases improper implementation of water fluoridation can result in overfluoridation that causes outbreaks of acute fluoride poisoningwith symptoms that include nauseavomitingand diarrhea.
Three such outbreaks were reported in Fluoridating agents U. Like other common water additives such as chlorinehydrofluosilicic acid and sodium silicofluoride decrease pH cause a small increase of corrosivitybut this problem is easily addressed by increasing the pH.
The effect of water fluoridation on the natural environment has been investigated, and no adverse effects have Fluoridating agents established. Issues studied have included fluoride concentrations in groundwater and downstream rivers; lawns, gardens, and plants; consumption of plants grown in fluoridated water; air emissions; and equipment noise. Fluoride
Fluoridating agents its major effect by interfering with the demineralization mechanism of tooth Fluoridating agents. Tooth decay is an infectious diseasethe key feature of is an increase within dental plaque of bacteria such as Streptococcus mutans and Lactobacillus.
These produce organic acids when carbohydrates, especially sugar, are eaten. After the sugar is gone, some of the mineral loss can be recovered—or Fluoridating agents —from ions dissolved in the saliva. Cavities result when the rate of demineralization exceeds the rate of remineralization, typically in a process that
Fluoridating agents many months or years. All fluoridation methods, including water fluoridation, create low levels of fluoride ions in saliva and plaque fluid, thus Fluoridating agents a topical or surface effect.
A person living in an area with fluoridated water may Fluoridating agents rises of fluoride concentration in saliva to about 0. Fluoride's effects depend on the Fluoridating agents daily intake of fluoride from all sources. High fluoride levels have been found in other including barley, cassava, corn, rice, taro, yams, and fish protein concentrate.
Institute of Medicine has established Dietary Reference Intakes for fluoride: Adequate Intake values range from Fluoridating agents. However, these values differ greatly among the Fluoridating agents regions: The views on the most effective method Fluoridating agents community prevention of tooth Fluoridating agents are mixed.
The Australian government review states that water
Fluoridating agents is the most effective means of achieving fluoride exposure that is community-wide. Fluoride toothpaste is Fluoridating agents most widely used and rigorously evaluated fluoride treatment. The
Fluoridating agents of salt fluoridation is about the same as that of water fluoridation, if most salt for human consumption is fluoridated. Fluoridated salt reaches the in salt at home, in meals at school and at large kitchens, and in bread.
For example, Jamaica has just one salt producer, but a Fluoridating agents public water supply; it started fluoridating all salt inachieving a decline in cavities. Universal salt Fluoridating agents is also practiced in Colombia and the Swiss Canton
Fluoridating agents Vaud ; in Germany fluoridated salt Fluoridating agents widely used in households but unfluoridated salt is also available, giving consumers a choice.
Fluoridating agents on location, the fluoride is added to milk, to powdered milkor to yogurt.
For example, milk powder fluoridation is used in rural Chilean areas
Fluoridating agents water fluoridation is not technically feasible. Other public-health strategies to control tooth decay,
Fluoridating agents as education to change behavior and diet, have lacked impressive results.
A Australian review concluded that water fluoridation is the most effective and socially the most equitable way to expose entire communities to fluoride's cavity-prevention effects.
The majority of those were in the United States. Much of the early work on establishing the connection fluoride and dental health was performed by scientists in the U. Inan estimated In some notably parts of Africa, China, and India, natural fluoridation exceeds
Fluoridating agents levels.
Communities discontinued water fluoridation in some countries, including Finland, Germany, Japan, the Netherlands, and Switzerland. There is also scientific evidence that fluoride in large amounts can lead to damage to health.
When fluoride is supplied via drinking water, there is no control regarding the amount of fluoride actually consumed, which could lead to excessive consumption. Supply of fluoridated water forces those who do not
Fluoridating agents wish to also consume water with added fluoride. This approach is therefore not accepted in most countries in the world. Fluoridating agents use of fluoride in its forms is the foundation of tooth decay prevention throughout Europe; several countries have introduced fluoridated Fluoridating agents, with varying success: In three other West European countries, Greece, Austria and the Netherlands, the legal framework for production and marketing of fluoridated edible salt exists.
The Slovak Republic had the equipment to treat salt
Fluoridating agents ; in the other four countries attempts to introduce Fluoridating agents salt were not successful.
The history of water fluoridation can be divided into three periods. The third period, from on, focused on adding fluoride to community water supplies. In the first half of the 19th century, investigators established that fluoride occurs with varying concentrations in teeth, bone, and drinking water. In the second Fluoridating agents they speculated that fluoride would protect against tooth decay, proposed supplementing the diet Fluoridating agents fluoride, and observed mottled enamel now called severe dental fluorosis without knowing the cause.
The foundation of water fluoridation in the U. McKay spent thirty years investigating the cause of what was then known as the Colorado brown stain, which produced mottled but also cavity-free teeth; with the help of Black and other researchers, he established that the cause was fluoride.
Inan Alcoa chemist, H. Churchill, concerned about a possible link between aluminum and staining, analyzed water from several areas where the staining was common and found that fluoride was the common factor.
Fluoridating agents s and early s, H. Trendley Dean Fluoridating agents colleagues at the newly created U. The results, published
Fluoridating agents significant reduction of Fluoridating agents. Fluoridation became an official policy of the U. Public Health Service byand by water fluoridation had become widely used in the U.
McKay's work had established that fluorosis occurred before tooth eruption. Dean and his colleagues assumed that fluoride's protection against cavities was also pre-eruptive, and this incorrect assumption was accepted for years. Byhowever, the topical effects of fluoride in both water Fluoridating agents agents toothpaste well understood, and it had Fluoridating agents known that a constant low level of fluoride in the mouth works best to prevent cavities.
Larger water systems have lower per capita cost, and the cost is also affected by the number of fluoride injection points in the water system, the type of feeder and monitoring equipment, the fluoride chemical and its transportation and storage, and water plant personnel expertise.
Although a workshop on cost-effectiveness of cavity prevention concluded that water fluoridation is one of the few public health measures that Fluoridating agents more money than they cost, little high-quality has been done on the cost-effectiveness and solid data
Fluoridating agents scarce.