Fluoridation as public health measures
‫وﺻﺎل ﻋﻠﻲ اﻟﻌﺒﯿﺪي‬.‫د‬.‫أ‬
History
The history of water fluoridation can be divided into three periods.
1. The first (c. 1901–1933) was research into the cause of a form of mottled tooth
enamel called the Colorado brown stain.
2. The second (c. 1933–1945) focused on the relationship between fluoride
concentrations, fluorosis, and tooth decay.
3. The third period, from 1945 on, focused on adding fluoride to community water
supplies.
Source of fluoride
• Drinking water is typically the largest source of fluoride.
• Dental products ex, toothpaste;
• Air pollution from fluoride-containing coal ;
• Foods, including ex, tea, corn, rice, and fish.
Water fluoridation: It is the controlled addition of fluoride to a public water supply to
reduce tooth decay. This can occur naturally or by adding fluoride.
Goal
The goal of water fluoridation is to prevent tooth decay by adjusting the
concentration of fluoride in public water supplies. Tooth decay (dental caries) is one of
the most prevalent chronic diseases worldwide.
• Although it is rarely life-threatening, tooth decay can cause pain and impair
eating, speaking, facial appearance, and acceptance into society especially in
children.
• Although the problem appears to be less in developing countries, it is expected to
increase because of changing diet and inadequate fluoride exposure.
• Oral disease is the fourth most expensive disease to treat.
Implementation
Fluoridation does not affect the appearance, taste, or smell of drinking water. It is
normally accomplished by adding one of three compounds to the water:
• Sodium fluoride (NaF) was the first compound used. It is a white, odorless
powder or crystal; the crystalline form is preferred if manual handling is used. It is
more expensive than the other compounds.
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• Fluorosilicic acid (H 2 SiF 6 ) is a liquid by-product.
• Sodium fluorosilicate (Na 2 SiF 6 ) is a powder or very fine crystal.
Level of fluoride
The optimal level of fluoride the is 1ppm (parts per million equivalent to
milligrams per liter). The optimal level is not appropriate for all parts of the world, so
the optimal level is range from 0.7 to 1.2 ppm and is depending on:
1. the average maximum daily air temperature; the optimal level is lower in warmer
climates, where people drink more water, and is higher in cooler climates.
2. Increase other sources of fluorides.
The use of optimal level of fluoride is to achieved maximum caries reduction with
minimum side effect (dental fluorosis).
Fluoride in naturally occurring water can be above, at, or below recommended levels;
• Rivers and lakes generally contain fluoride levels less than 0.5 mg/L,
• Groundwater can contain as much as 50 mg/L.
• Bottled water typically has unknown fluoride levels,
• Some home water filters remove some or all fluoride.
Defluoridation
It is a process to remove excessive amounts of fluorides when the level exceeds
recommended limits in naturally fluoridated waters. Defluoridation is carried out by
adding chemicals to precipitate the fluoride. Chemicals usually used include: calcium
oxide, magnesium compounds, etc.
Mechanism
Fluoride exerts its major effect by interfering with the demineralization mechanism
of tooth decay. The caries-prevention effect of fluoride is mostly due to systemic effect
which occur during tooth formation, as well as surface (topical) effect, which occur after
tooth eruption.
Tooth decay is an infectious disease. The bacteria such as Streptococcus mutans and
Lactobacillus produce acids when carbohydrates, especially sugar, are eaten. When
enough acid is produced so that the pH goes below 5.5, the acid dissolves
hydroxyapatite of tooth enamel, in a process known as demineralization. After the sugar
is gone, some of the mineral loss can be recovered—or remineralized—from ions
dissolved in the saliva. Caries result when the rate of demineralization exceeds the rate
of remineralization.
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Fluoride therapy
• Drinking water is typically the largest source;
Water fluoridation has advantages, especially for subgroups at high risk. It is
effective at reducing caries in both children and adults. With studies estimating up to
40% reduction in caries. Which is either:
1. Communal water fluoridation:
2. School water fluoridation:
The important thing is the optimal level of fluoride in school water fluoridation is
about 4.5 times that of the communal water fluoridation because children spend
only part of their day in the school.
• Alternatives methods of fluoride therapy:
Although water fluoridation is the most effective means of achieving fluoride exposure
that is community-wide, other fluoride therapies are also effective in preventing tooth
decay systemically; they include:
1. Fluoridated tablets:
The age of the patient and area of residence in consideration. The child instructed
to chew the tablets between his teeth to have topical and the systemic effect of
fluoride.
2. Fluoridation of salt and milk:
The effectiveness of salt fluoridation is about the same as that of water
fluoridation, if most salt for human consumption is fluoridated. Fluoridated milk
benefits schoolchildren, especially their permanent teeth. Depending on location,
the fluoride is added to milk, to powdered milk, or to yogurt.
• Topical fluoride application…………….
1. Fluoride toothpaste, fluoridated mouth rinses, gels:
These are the self-applied topical fluoride application of low concentration.
It is widely used. It relies on individual and family behavior.
2. Mouthwash, gel, varnish, and dental sealants:
These are the professional fluoride application of high concentration.
All fluoridation methods, including water fluoridation, create low levels of fluoride ions
in saliva and plaque fluid, thus exerting a topical or surface effect.
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Side effects
Fluoride's adverse effects depend on total fluoride dosage from all sources. About
70–90% of ingested fluoride is absorbed into the blood, where it distributes throughout
the body. About 99% of retained fluoride is stored in bone, teeth, and other calcium-rich
areas.
• At the commonly recommended dosage, the only clear adverse effect is a mild
dental fluorosis (which is a hypoplastic defect of enamel formation by excessive
fluoride systemically during tooth development).
• Fluoride can occur naturally in water in concentrations above recommended
levels:
1. which can have several long-term (chronic) adverse effects, including:
--Dental fluorosis, which can alter the appearance of children's teeth
during tooth development.
--Skeletal fluorosis, and weakened bones.
2. In rare cases, it can cause acute fluoride poisoning, with symptoms that
include:
-- nausea, vomiting, and diarrhea.
Ethics and politics
Fluoridation presents a conflict between communal benefit and a violation of
individual rights. Fluoridation can be viewed as:
• a violation of ethical or legal rules that “prohibit medical treatment without
medical supervision or informed consent”.
• a public intervention to replicate the benefits of naturally fluoridated water in
order to free people from the misery of toothache and dental work, with greatest
benefit to those least able to help themselves.
The motivation for fluoridation of water or salt is similar to that of iodized salt for the
prevention of mental retardation and goiter.
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