Water fluoridation is the addition of controlled fluoride to the public water supply to reduce tooth decay. Fluoridated water contains fluoride at an effective level to prevent cavities; this can occur naturally or by adding fluoride. Fluoridation of water operates on the tooth surface: inside the mouth, it creates a low level of fluoride in the saliva, which reduces the rate at which the demineral tooth enamel and increases the rate at which it remineralizes at an early stage of the cavity. Usually fluoride compounds are added to drinking water, a process that in the US spends an average of about $ 1.06 per person per year. Defluoridation is required when naturally occurring fluoride levels exceed the recommended limits. In 2011, the World Health Organization recommended a fluoride level of 0.5-1.5 mg/L (milligrams per liter), depending on climate, local environment, and other sources of fluoride. Bottled water usually has unknown levels of fluoride.
Dental caries remains a major public health problem in most industrialized countries, affecting 60-90% of schoolchildren and most adults. Water fluoridation reduces cavities in children, while efficacy in adults is less clear. A Cochrane review estimates a reduction in cavities when water fluoridation is used by children who do not have access to other sources of fluoride to 35% in baby teeth and 26% in permanent teeth. The quality of evidence is bad. Most European countries have experienced a major decline in tooth decay without their use, but the fluoridation of milk and salt is widespread. Recent studies have shown that water fluoridation, especially in industrialized countries, may not be necessary because topical fluoride (such as toothpaste) is widely used, and caries levels are low.
Although fluoridation can cause dental fluorosis, which may alter the appearance of developing teeth or enamel fluorosis, the difference is mild and is usually not considered an aesthetic or public health problem. There is no clear evidence of any other adverse effects of water fluoridation. The fluoride effect depends on the total daily intake of fluoride from all sources. Drinking water is usually the largest source; Other fluoride therapy methods include fluoridation of toothpaste, salt, and milk. The views on the most efficient methods for prevention of tooth decay communities vary. The Australian Government states that water fluoridation is the most effective way to achieve widespread fluoride exposure throughout the community. The World Health Organization reports that water fluoridation, when feasible and culturally acceptable, has substantial benefits, especially for high-risk subgroups, while the European Commission found no benefit for water fluoridation compared with topical use.
General water fluoridation was first practiced in the US. In 2012, 25 countries have artificial fluoridation of water at various levels, 11 of which have more than 50% of their population drinking fluoridated water. Further 28 countries have naturally fluoridated water, although in many countries fluoride is above the recommended safe level. In 2012, approximately 435 million people worldwide receive water fluoridation at the recommended level (ie about 5.4% of the global population). About 214 million of them live in the United States. Major health organizations such as the World Health Organization and FDI World Dental Federation support water fluoridation as safe and effective. The Centers for Disease Control and Prevention lists water fluoridation as one of the top ten outstanding public health achievements of the 20th century in the United States. However, this practice is controversial as a public health measure; some countries and communities have stopped it, while others have expanded it. Opponents of the practice argue that both the benefits and the risks have been adequately addressed, and debate the conflict between what might be considered a mass treatment and individual freedom.
Video Water fluoridation
Destination
The purpose of water fluoridation is to prevent tooth decay by adjusting the fluoride concentration in the public water supply. Tooth decay (dental caries) is one of the most common chronic diseases worldwide. Although rarely life-threatening, tooth decay can cause pain and eating disorders, speech, facial appearance, and acceptance to society, and that greatly affects the quality of life of children, especially those with low socioeconomic status. In most industrialized countries, tooth decay affects 60-90% of schoolchildren and most adults; although problems appear to be lacking in African developing countries, are expected to increase in some countries there due to inadequate dietary changes and fluoride exposure. In the US, the minority and the poor both have levels of decayed and missing teeth, and their children have fewer dental treatments. Once the cavity occurs, the fate of the tooth is a repeating restoration, with an estimate for median life of amalgam dental filling ranging from 9 to 14 years. Mouth disease is the fourth most expensive disease to treat. The motivation for fluoridation of salt or water is similar to iodized salt for the prevention of intellectual disabilities and goiter.
The purpose of fluoridation of water is to prevent chronic illness whose burden mainly falls on children and the poor. One other goal is to bridge inequalities in dental and dental care. Several studies have shown that fluoridation reduces the inequalities of oral health between the rich and the poor, but the evidence is limited. There is anecdotal but unscientific evidence that fluoride allows more time for dental treatment by slowing the progression of tooth decay, and it simplifies treatment by causing most of the cavities to occur in cavities and tooth cavities. Other reviews did not find sufficient evidence to determine whether water fluoridation reduces social inequalities in oral health.
Health and dental organizations around the world have validated their safety and effectiveness. Its use began in 1945, after studying children in areas where higher levels of fluoride occur naturally in water. Further studies show that moderate fluoridation prevents tooth decay.
Maps Water fluoridation
Implementation
Fluoridation does not affect the appearance, taste, or smell of drinking water. Usually done by adding one of the three compounds to water: sodium fluoride, fluorosilicic acid, or sodium fluorosilicate.
- Sodium fluoride (NaF) is the first compound to be used and is a reference standard. It is white powder or crystal, odorless; crystalline form is preferred if manual handling is used, because it minimizes dust. These are more expensive than other compounds, but are easy to handle and are typically used by smaller utility companies. It is toxic in grams through consumption or inhalation.
- Fluorosilicic Acid (H 2 SiF 6 ) is the most common additive used for water fluoridation in the United States. This is a cheap liquid product from the manufacture of phosphate fertilizers. It comes in a variety of strengths, usually 23-25%; because it contains so much water, shipping can be expensive. It is also known as hexafluorosilicic, hexafluosilic, hydrofluosilicic, and silicofluoric acid.
- Sodium fluorosilicate (Na 2 SiF 6 ) is a sodium salt of fluorosilicic acid. This is a very fine powder or crystal that is more easily shipped than fluorosilicic acid. It is also known as sodium silicofluoride.
These compounds are selected for their solubility, safety, availability, and low cost. The 1992 census found that, for the US public water supply system that reported the type of compound used, 63% of the population received fluoridated water with fluorosilicic acid, 28% with sodium fluorosilicate, and 9% with sodium fluoride.
Recommendations
The Centers for Disease Control and Prevention develop recommendations for water fluoridation that specify requirements for personnel, reporting, training, inspection, monitoring, monitoring, and action in overfeed cases, together with technical requirements for each major compound used.
Although fluoride was once considered an essential nutrient, the US National Research Council has omitted this designation because of a lack of research that suggests it is important for human growth, although it is still considering fluoride as a "beneficial element" because of its positive impact on oral health.. The European Food Safety Authority panel on Diet Products, Nutrition and Allergies (NDA) considers fluoride not to be an essential nutrient, however, because the beneficial effects of the fluoride diet on prevention of dental caries have defined the value of Adequate Intake (AI) for it. AI fluoride from all sources (including non-dietary sources) is 0.05 mg/kg body weight per day for children and adults, including pregnant and lactating women.
In 2011, the US Department of Health and Human Services (HHS) and the US Environmental Protection Agency (EPA) lowered the recommended fluoride level to 0.7 mg/L. By 2015, the US Food and Drug Administration (FDA) recommendation from the US Public Health Service (PHS) for the fluoridation of community water systems, recommends that bottled water manufacturers limit fluoride in bottled water to no more than 0.7 milligrams per liter (mg/L) (milligrams per liter, equivalent to parts per million ).
The previous recommendations are based on an evaluation from 1962, when the US established optimal fluoride levels ranging from 0.7-1.2 mg/L (milligrams per liter, equivalent to parts per million), depending on the average maximum daily air temperature; Optimal levels are lower in warmer climates, where people drink more water, and are higher in cold climates.
These standards are not suitable for all parts of the world, where fluoride levels may be excessive and fluoride must be removed from water, and based on assumptions that have become obsolete with the advent of air conditioning and increased use of soft drinks, processed foods, fluoridated toothpaste, and sources other fluorides. In 2011 the World Health Organization stated that 1.5 mg/L should be an absolute upper limit and 0.5 mg/L may be an appropriate lower threshold. A 2007 Australian systematic review recommends a range of 0.6-1.1 mg/L.
Events
Fluoride that occurs naturally in water can be above, at, or below the recommended level. Rivers and lakes generally contain fluorine levels of less than 0.5 mg/L, but groundwater, particularly in volcanic or mountainous areas, may contain as much as 50 mg/L. Higher fluorine concentrations are found in volcanic, hydrothermal, , and others derived from the highly evolved magma and hydrothermal solution, and this fluorine dissolves into the adjacent water as fluoride. In most drinking water, more than 95% of total fluoride is the F - ion, with the magnesium-fluoride complex (MgF ) being the next most common. Since fluoride levels in water are usually controlled by fluorite solubility (CaF 2 ), high levels of natural fluoride are associated with deficient calcium, alkaline, and soft water. Defluoridation is required when naturally occurring fluoride levels exceed the recommended limits. This can be achieved by seeping water through the granular layer of active alumina, bone meal, bone char, or tricalcium phosphate; with coagulation with alum; or with precipitation with lime.
Pitchers or water filters installed in the faucet do not alter the fluoride content; More expensive reverse osmosis filters remove 65-95% fluoride, and distillation eliminates all fluoride. Some bottled water contains undetermined fluoride, which may be present naturally in the source water, or if water is sourced from the fluoridated general supply. The FDA states that bottled water products labeled as deionized, purified, demineralized, or distilled have been treated in such a way that they do not contain or only track fluoride counts unless they specifically list fluoride as an additive.
Evidence
Existing evidence suggests that water fluoridation reduces tooth decay. Consistent evidence also suggests that it causes dental fluorosis, which is mostly mild and is usually not an aesthetic problem. There is no clear evidence of any other side effects, although most of the research has poor quality.
Effectiveness
Reviews have shown that water fluoridation reduces tooth decay in children. The conclusions for efficacy in adults are less clear with some reviews finding benefits and others not. Studies in the US in the 1950s and 1960s showed that water fluoridation reduced childhood cavities by fifty to sixty percent, while studies in 1989 and 1990 showed a lower decline (40% and 18% ), possibly due to increased use of fluoride from other sources. , especially toothpaste, and also the 'halo effect' of foods and beverages made in areas containing fluoride and consumed in non-humidified ones.
A systematic review of UK 2000 (York) found that water fluoridation was associated with a decrease in the proportion of children with 15% perforated teeth and with declining decayed, missing, and filled primary teeth (average decrease was 2.25 teeth). The study found that evidence has moderate quality: some studies attempt to reduce observer bias, control for confounding factors, report variance measurements, or use appropriate analysis. Although there is no major difference between natural and artificial fluoridation, evidence is inadequate for conclusions about differences. The 2007 Australian systematic review used the same inclusion criteria as the York criteria, plus one additional study. This did not affect York's conclusions. The systematic review of the European Commission 2011 is based on its effectiveness on the conclusions of the York review. The systematic Cochrane 2015 review estimates cavity reduction when water fluoridation is used by children who do not have access to other sources of fluoride to 35% in baby teeth and 26% on permanent teeth. The evidence is of poor quality.
Fluoride can also prevent cavities in adults of all ages. A 2007 meta-analysis by CDC researchers found that water fluoridation prevented about 27% of the cavities in adults, around the same fraction as those prevented by exposure to fluoride delivery methods (29% on average). A review of the European Commission 2011 found that the benefits of water fluoridation for adults in terms of reduced decay are limited. The 2015 Cochrane Review found no conclusive research on the effectiveness of water fluoridation in adults. A 2016 review found evidence of variable quality that, in aggregate, discontinuation of community water fluoridation programs is usually followed by increased cavities.
Most countries in Europe have experienced a substantial decrease in cavities without using water fluoridation. For example, in Finland and Germany, tooth decay rates remain steady or continue to decline after fluoridation of water stops. Fluoridation may be useful in the US. Because unlike most other European countries, the US has no school-based dental care, many children do not visit dentists regularly, and for many US children, fluoridation of water is a major source of exposure to fluoride. The effectiveness of fluoridation of water may vary according to circumstances such as whether dental preventive care is free for all children.
Fluorosis
Fluoride side effects depend on the total dose of fluoride from all sources. At the recommended dosage, the only obvious side effect is dental fluorosis, which can change the appearance of children's teeth during dental development; this is mostly mild and may not represent a real effect on aesthetic appearance or on public health. In April 2015, the recommended fluoride levels in the United States are converted to 0.7 ppm from 0.7-1.2 ppm to reduce the risk of dental fluorosis. The 2015 Cochrane Review estimates that for 0.7 ppm fluoride levels, the percentage of participants with esthetic awareness fluorosis is about 12%. This increases to 40% when considering fluorosis at any level that is not an aesthetic problem. In the US, mild or mild tooth fluorosis has been reported in 20% of the population, moderate fluorosis in 2% and severe fluorosis less than 1%.
The critical period of exposure is between the ages of one to four, with the risk of ending around the age of eight. Fluorosis can be prevented by monitoring all sources of fluoride, with fluoride water directly or indirectly responsible for about 40% risk and other sources, especially toothpaste, responsible for the remaining 60%. Compared with naturally fluoridated water at 0.4 mg/L, fluoridation of up to 1 mg/L is estimated to cause additional fluorosis in one of every 6 people (95% CI 4-21 people), and cause additional fluorosis of aesthetic attention in one of every 22 people (95% CI 13.6-? person). Here, aesthetic concern is the term used on a standard scale based on what teenagers will find unacceptable, as measured by a 1996 study of 14-year-olds. In many industrialized countries fluorosis prevalence is increasing even in undefined communities, mainly due to fluoride from ingested toothpaste. A systematic review of 2009 indicates that fluorosis is associated with the consumption of infant or water formulas added to reconstitute the formula, that the evidence is distorted by publication bias, and that evidence that fluoride formulas causes weak fluorosis. In the US declining dental decline is accompanied by increased fluorosis in both fluoridated and unfluoridated communities; thus, fluoride has been reduced in various ways around the world in infant formula, children's toothpaste, water, and fluoride supplement schedule.
Security
Fluoridation has little effect on the risk of fractures (fractures); This can result in a fracture risk slightly lower than an excessive fluoridation rate or no fluoridation. There is no clear relationship between fluoridation and cancer or cancer deaths, both for cancer in general and also specifically for bone and osteosarcoma cancer. Other adverse effects are not sufficient evidence to reach a conclusive conclusion.
Fluoride can occur naturally in water in concentrations well above the recommended level, which may have some long-term adverse effects, including severe dental fluorosis, skeletal fluorosis, and weakened bone; water utilities in developed countries reduce fluorine levels to the maximum levels set in areas where natural levels are high, and WHO and other groups work with countries and regions in developing countries with excessive fluoride levels naturally to achieve safe levels. The World Health Organization recommends a maximum fluoride value guideline of 1.5 mg/L as the rate at which fluorosis should be minimal.
In rare cases, improper water fluoridation practices can lead to overfluoridation that causes acute poisoning of fluoride poisoning, with symptoms that include nausea, vomiting, and diarrhea. Three outbreaks were reported in the US between 1991 and 1998, caused by a fluoride concentration as high as 220 mg/L; in the Alaska outbreak of 1992, 262 people became ill and one died. In 2010, about 60 gallons of fluoride were released to water supplies in Asheboro, North Carolina within 90 minutes - the intended amount to be released within a 24-hour period.
Like other common water additives such as chlorine, hydrofluosilic acid and sodium silicofluoride decrease the pH and lead to a small increase in corrosivity, but this problem is easily overcome by increasing the pH. Although it has been hypothesized that hydrofluosilic acid and sodium silicofluoride may increase human lead uptake from water, the 2006 statistical analysis does not support the concern that these chemicals lead to higher blood lead concentrations in children. Track arsenic and lead levels may be present in fluoride compounds added to water, but there is no reliable evidence that their presence is of concern: concentrations are below the measurement limit.
The effect of water fluoridation on the natural environment has been investigated, and no side effects have been established. The problems studied include the concentration of fluoride in ground water and downstream streams; lawns, gardens, and plants; consumption of plants grown in fluoridated water; air emissions; and equipment noise.
Mechanism
Fluoride gives its main effect by interfering with the demineralization mechanism of tooth decay. Tooth decay is an infectious disease, a key feature that is an increase in bacterial tooth plaques such as Streptococcus mutans and Lactobacillus . It produces organic acids when carbohydrates, especially sugars, are eaten. When enough acid is produced to lower the pH below 5.5, the acid dissolves the carbonated hydroxyapatite, the main component of tooth enamel, in a process known as demineralization. After the sugar is gone, some mineral loss can be recovered - or remineralization - of the ion dissolved in the saliva. Cavity results when the demineralization rate exceeds the level of remineralization, usually in a process that takes months or years.
All fluoridation methods, including water fluoridation, produce low amounts of fluoride ions in saliva and plaque fluid, thus exerting topical or surface effects. A person living in an area with fluoridated water may experience an increase in fluoride concentration in the saliva of about 0.04 mg/L several times during the day. Technically, these fluorides do not prevent cavities but control the rate at which they develop. When the fluoride ion is present in the plaque fluid along with the dissolved hydroxyapatite, and the pH is higher than 4.5, the fluorapatite remineralization veneer is formed on the surface of the remaining enamel; The veneer is much more acid-resistant than the original hydroxyapatite, and is formed more rapidly than ordinary remineralized enamel. The effects of fluoride cavity prevention are largely due to these surface effects, which occur during and after dental eruptions. Although some systemic (whole body) fluorides return to the saliva through the blood plasma, and to the un-erupted tooth via plasma or crypt fluid, there is little data to determine what percentage of the anti-oxidant effects of fluoride derived from this systemic mechanism. Also, although fluoride affects the physiology of tooth bacteria, its effect on bacterial growth seems irrelevant to cavity prevention.
The fluoride effect depends on the total daily intake of fluoride from all sources. Approximately 70-90% of swallowed fluoride is absorbed into the blood, where it is distributed throughout the body. In infants 80-90% of absorbed fluoride is retained, with the remainder removed, mostly by urine; in adults about 60% is maintained. Approximately 99% of stored fluoride is stored in bones, teeth, and other calcium-rich areas, where excess amounts can cause fluorosis. Drinking water is usually the largest source of fluoride. In many industrialized countries, toothpaste ingested is a major source of fluoride exposure in unlocalized communities. Other sources include dental products other than toothpastes; air pollution from coal containing fluoride or from phosphate fertilizers; trona, used to soften meat in Tanzania; and tea leaves, especially preferred tea bricks in parts of China. High levels of fluoride have been found in other foods, including barley, cassava, corn, rice, taro, sweet potatoes, and fish protein concentrates. The US Medical Institute has established a food reference intake for fluoride: Adequate intake values ​​range from 0.01 mg/day for infants aged 6 months or less, up to 4 mg/day for men aged 19 and older; and Tolerable Intake Rate is 0.10 mg/kg/day for infants and children up to 8 years of age, and 10 mg/day thereafter. A rough estimate is that adults in temperate climates consume 0.6 mg/day of fluoride without fluoridation, and 2 mg/day with fluoridation. However, these values ​​differ greatly among regions of the world: for example, in Sichuan, China the average daily fluoride intake is only 0.1 mg/day in drinking water but 8.9 mg/day in food and 0.7 mg/day directly from the air due to the use of high fluoride soft coal for cooking and drying groceries indoors.
Alternative
The views on the most effective methods for prevention of tooth decay communities vary. A review of the Australian government states that water fluoridation is the most effective way to achieve fluoride exposure that exists throughout the community. The EC review states "There is no clear advantage in supporting water fluoridation compared with topical prevention". Other fluoride therapy is also effective in preventing tooth decay; they include fluoride toothpaste, mouthwash, gel, and varnish, and fluoridated salt and milk. Dental sealants are also effective, with the estimated cavities prevented ranging from 33% to 86%, depending on the age of the sealant and the type of study.
The fluoride toothpaste is the most widely used and rigorously assessed fluoride treatment. Introduction in the early 1970s is considered a major reason for the decline in tooth decay in industrialized countries, and toothpaste appears to be a single common factor in countries where tooth decay has declined. Toothpaste is the only realistic fluoride strategy in many low-income countries, where lack of infrastructure makes water or salt fluoridation unfeasible. It depends on individual and family behavior, and its use is less likely among lower economic classes; in low-income countries is not reached by the poor. The fluoride toothpaste prevents about 25% of the cavities on young permanent teeth, and their effectiveness increases if higher fluoride concentrations are used, or if brushing is monitored. Gargle and fluoride gel are as effective as fluoride toothpaste; fluoride varnish prevents about 45% of the cavities. For comparison, brushing with nonfluoride toothpaste has little effect on cavities.
The effectiveness of salt fluoridation is similar to water fluoridation, if most of the salt for human consumption is fluoride. Fluoride salts reach consumers in salt at home, in school meals and in large kitchens, and on bread. For example, Jamaica has only one salt producer, but a complex public water supply; it started fluoridating all salt in 1987, achieving a decline in cavities. Garamation of universal salt is also done in Colombia and Switzerland Canton of Vaud; in Germany fluoride salts are widely used in households but non-reconstituted salts are also available, giving consumers choice. The concentration of fluoride in salt ranged from 90 to 350 mg/kg, with the study showing an optimal concentration of about 250 mg/kg.
Milk fluoridation is done by the Borrow Foundation in parts of Bulgaria, Chile, Peru, Russia, Macedonia, Thailand and the UK. Depending on the location, fluoride is added to milk, milk powder, or yogurt. For example, fluoridated milk powder is used in rural Chile where water fluoridation is not technically feasible. These programs are intended for children, and are not targeted or evaluated for adults. A systematic review found low-quality evidence to support the practice, but also concluded that more research is needed.
Other public health strategies for controlling tooth decay, such as education to change behavior and diet, have no impressive results. Although fluoride is the only well-documented agent that controls the rate at which cavities develop, it has been suggested that adding calcium to water will reduce further cavities. Other agents to prevent tooth decay include antibacterials such as chlorhexidine and sugar substitutes such as xylitol. Chewing gum with Xylitol has been recommended as a supplement for fluoride and other conventional treatments if chewing gum is not too expensive. Two proposed approaches, bacterial replacement therapy (probiotics) and caries vaccine, will share the benefits of water fluoridation requiring only minimal patient compliance, but have not been proven safe and effective. Other experimental approaches include fluoride sugar, polyphenols, and casein phosphate calcium casein-phosphopeptide-amorphous phosphopeptides.
The 2007 Australia Review concludes that water fluoridation is the most effective and most socially fair way to expose the entire community to the prevention effect of fluoride cavities. The 2002 US study estimated that sealants lowered the cavity by about 60% overall, compared to about 18-50% for fluoride. The 2007 Italian study suggests that water fluoridation may not be necessary, especially in industrialized countries where cavities are scarce, and conclude that other topical toothpaste and fluoride is the best way to prevent cavities around the world. The World Health Organization's 2004 review stated that water fluoridation, if culturally acceptable and technically feasible, has a substantial advantage in preventing tooth decay, especially for high-risk subgroups.
Usage
As of November 2012, a total of about 378 million people worldwide received artificial fluoride water. The majority of them are in the United States. About 40 million worldwide receive water that is naturally fluoridated to the recommended level.
Much of the initial work to establish a link between fluoride and dental health was done by scientists in the US during the early 20th century, and the United States was the first country to apply large-scale public fluoridation of water. It has been introduced to various levels in many countries and regions outside the US, including Argentina, Australia, Brazil, Canada, Chile, Colombia, Hong Kong, Ireland, Israel, Korea, Malaysia, New Zealand, Philippines, Serbia, Singapore, Spain, England, and Vietnam. In 2004, an estimated 13.7 million people in Western Europe and 194 million in the US received artificial fluoride water. In 2010, about 66% of the US population received fluoridated water.
Natural fluoride water is used by about 4% of the world's population, in countries including Argentina, France, Gabon, Libya, Mexico, Senegal, Sri Lanka, Tanzania, USA and Zimbabwe. In some locations, especially in Africa, China, and India, natural fluoridation exceeds the recommended level.
Communities have stopped water fluoridation in some countries, including Finland, Germany, Japan, the Netherlands and Switzerland. On August 26, 2014, Israel ceased its fluoridation mandate, stating "Only about 1% of water is used for drinking, while 99% of water is intended for other uses (industry, agriculture, flushing toilets etc.) There is also scientific evidence that fluoride in large quantities can cause damage to health.When fluoride is supplied through drinking water, there is no control over the actual amount of fluoride consumed, which can lead to excessive consumption.Fluoridated water supplies are forcing those who do not expect water consumption with the addition of fluoride.Therefore this approach not accepted in most countries of the world. "This change is often motivated by political opposition to water fluoridation, but sometimes the need for water fluoridation is met by alternative strategies. The use of fluoride in its various forms is the foundation of preventing tooth decay throughout Europe; several countries have introduced fluoride salts, with success: in Switzerland and Germany, fluoride salts represent 65% to 70% of the domestic market, while in France market share reached 60% in 1993 but decreased to 14% in 2009; Spain, in 1986 the second Western European country to introduce table salt fluoridation, reported the market share in 2006 was only 10%. In three other Western European countries, Greece, Austria and the Netherlands, the legal framework for the production and marketing of salt can be eaten fluoride. At least six Central European countries (Hungary, Czech Republic and Slovakia, Croatia, Slovenia, Romania) have shown an interest in salt fluoridation; However, significant usage of about 35% is only achieved in the Czech Republic. The Slovak Republic has equipment to treat salt in 2005; in four other countries trying to introduce fluoride salt was unsuccessful.
History
The history of water fluoridation can be divided into three periods. The first ( c. 1801-1933 ) is a study of the cause of a branched tooth enamel form called Colorado brown stain. The second (c.1933-1945) focuses on the relationship between fluoride concentration, fluorosis, and tooth decay, and establishes that moderate fluoride levels prevent cavities. The third period, from 1945, focused on adding fluoride to a community water supply.
In the first half of the 19th century, researchers determined that fluoride occurred with various concentrations in teeth, bones, and drinking water. In the second half they speculated that fluoride would protect teeth from tooth decay, proposed to supplement the diet with fluoride, and observed the presence of enamel stripes (now called severe dental fluorosis) without knowing the cause. In 1874, German public health worker Carl Wilhelm Eugen Erhardt recommended a potassium fluoride supplement to maintain teeth. In 1892, British physician James Crichton-Browne noted in an address that the absence of fluoride from the diet has produced teeth "particularly susceptible to decay", and which proposes "reintroduction into our diet... from fluorine in some natural form that according...... to fortify the next generation of teeth ".
The cornerstone of water fluoridation in the US is a study of dentist Frederick McKay (1874-1959). McKay spent thirty years investigating what came to be known as Colorado brown stains, which produced dappled but cavity-free teeth; with the help of G.V. Black researchers and others, he determined that the cause is fluoride. The first report of the statistical relationship between stains and lack of tooth decay was made by British dentist Norman Ainsworth in 1925. In 1931, an Alcoa chemist, H.V. Churchill, concerned about the possible relationship between aluminum and coloring, analyzed water from several areas where common coloring occurred and found that fluoride was a common factor.
In the 1930s and early 1940s, H. Trendley Dean and his colleagues at the newly established US National Institute of Health published several epidemiological studies showing that fluoride concentrations of about 1 mg/L were associated with much lower cavities in temperate regions moderate, and that fluorosis increases but only to a level with no medical or aesthetic problems. Other studies found no significant other side effects even in areas with fluoride levels as high as 8 mg/L. To test the hypothesis that adding fluoride would prevent cavities, Dean and his colleagues conducted a controlled experiment with water fluoridation in Grand Rapids, Michigan, January 1945. The results, published in 1950, show a significant decline in cavities. Significant tooth decay was also reported by important preliminary studies outside the US, including the Brantford-Sarnia-Stratford study in Canada (1945-1962), the Tiel-Culemborg study in the Netherlands (1953-1969), the Hastings study in New Zealand (1954- 1970), and the study of the Department of Health in England (1955-1960). By today's standards, these and other pioneering studies are crude, but large reductions in cavities convince public health professionals about the benefits of fluoridation.
Fluoridation became the official policy of the US Public Health Service in 1951, and by 1960 fluoridated water had been widely used in the US, reaching about 50 million people. In 2006, 69.2% of the US population in the public water system received fluoridated water, 61.5% of the total US population; 3.0% of the population in the public water system receives natural fluoride. In some other countries, the pattern is similar. New Zealand, which leads the world in per capita consumption of sugar and has the worst tooth in the world, started fluoridation in 1953, and in 1968 fluoridation was used by 65% ​​of the population served by tap water supply. Fluoridation was introduced to Brazil in 1953, regulated by federal law beginning in 1974, and in 2004 used by 71% of the population. In the Republic of Ireland, fluoridation was enacted in 1960, and after the constitutional challenges of the two major cities Dublin and Cork began in 1964; fluoridation became necessary for all large public water systems and in 1996 accounted for 66% of the population. In other locations, fluoridation was used and then discontinued: in Kuopio, Finland, fluoridation was used for decades but was stopped because the dental services provided a significant fluoride program and the risk of low space, and in Basel, Switzerland, it was replaced with fluoride salts.
McKay's work has determined that fluorosis occurs before a tooth eruption. Dean and his colleagues assume that fluoride protection against cavities is also pre-eruptive, and these false assumptions are accepted over the years. However, in 2000, the topical effects of fluoride (both in water and toothpaste) are well understood, and it is well known that low fluoride levels in the mouth work best to prevent cavities.
Economy
Fluoridation costs approximately $ 1.06 per person-year on average (range: $ 0.25- $ 11.19; all costs in this paragraph are for the US and in 2017 dollars, adjusted for inflation from previous estimates). Larger water systems have lower per capita costs, and costs are also influenced by the number of fluoride injection points in water systems, types of feeding and monitoring equipment, fluoride chemicals and their transport and storage, as well as the expertise of water installation personnel. In affluent countries the cost of salt fluoridation can also be ignored; developing countries may find it expensive to import fluoride additives. In comparison, fluoride toothpaste costs about $ 9 - $ 18 per person-year, at an additional cost to zero for people who have brushed their teeth for other reasons; and dental cleaning and fluoride varnish or gel applications cost about $ 97 per person per year. Assuming the worst case, with the lowest effectiveness estimates and the highest estimated operating costs for small towns, the cost of fluoridation is estimated at $ 16- $ 25 per surface of stored tooth decay, which is lower than the $ 95 forecast to recover the surface and an approximate $ 162 averaged cost-discounted lifetime of a decaying surface, which includes the cost of maintaining a restored tooth surface. It is not known how much is spent in industrialized countries to treat dental fluorosis, which is largely due to fluoride from ingested toothpaste.
Although a 1989 workshop on the cost-effectiveness of cavity prevention concluded that water fluoridation is one of several public health measures that save more money than their costs, little high-quality research has been done on cost-effectiveness and rare solid data. Dental sealants are only cost-effective when applied to high-risk children and teeth. The 2002 US study estimated that on average, the first permanent molar obstruction saves costs when they decompose faster than 0.47 per person per year while water fluoridation saves costs when total decay exceeds 0.06 surfaces per person-year. In the US, water fluoridation is more cost-effective than other methods to reduce tooth decay in children, and the 2008 review concludes that water fluoridation is the best tool for fighting tooth decay in many countries, especially among socially disadvantaged groups. A review of 2016 studies published between 1995 and 2013 found that water fluoridation in the US is cost effective, and that is more prevalent in larger communities.
US data from 1974 to 1992 showed that when water fluoridation was introduced into the community, there was a significant decrease in the number of employees per dental company and number of dental companies. Data show that some dentists respond to demand shocks by moving to non-fluoridated areas and by retraining as specialists.
Controversy
Water fluoridation controversy arises from political, moral, ethical, economic, and safety concerns about water fluoridation from public water supplies. Public health authorities around the world claim that water fluoridation at the right level is a safe and effective way to prevent dental caries. The most effective authority view on fluoride therapy for prevention of tooth decay communities is mixed; some of the country's water fluoridations are most effective, while others see no particular advantage and prefer a topical application strategy.
Opponents argue that water fluoridation has little or no caricotic benefit, can cause serious health problems, is not effective enough to justify the costs, and is pharmacologically obsolete, while some argue that this practice presents a conflict between the common rights and the rights individual.
See also
- History of water supply and sanitation
References
External links
- Fluoridation in Curlie (based on DMOZ)
Source of the article : Wikipedia
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