Fluoride(F-) is the simplest anion of fluorine and a natural material which make building bone and teeth. Fluoride reduces the damage to the enamel layer by configuring the flour apatite and its contribution to the tooth enamel. Fluorine ions reduce the speed of removing minerals from the enamel layer and increase the speed of metals to older persons in the early stages of decay. Fluorine such effects through the removal and re-metals to tooth2 the metals occur when fluorine in the oral cavity. And after it is swallowed fluorine become less impact.3 There are three initial interactions include ion fluorine for mineralization4
Iso-ionic exchange of F’ for OH’ in appetite: Ca10(PO4)6(OH)2 + 2F’ ‘ Ca10(PO4)6F2 + 2OH’
The substitution of ionic ion between fluorine and hydroxide in apatite and crystalline growth of fluorapatite from a solution above saturation are possible to occur during exposure to a small amount of fluorine (0.01-10 ppm per million ) for long periods of time and this happens in the mouth, briefly, when the use of products containing fluorine2 There are interested in the study of the impact of fluorine to microorganism found in the mouth, and concluded that the fluorine does not react as countermeasures, but also reduces the bacteria sticks to teeth with reduced removing minerals from it. Fluoride can be find it by many chemical methods (sodium fluoride, stenos fluoride, amino fluoride, mono fluoro phosphate, and many others) .
Second: Fluoride intake:
There are various sources contain fluoride, some of which has a simple and rich quantities such as milk and cheese. These sources include drinking water containing natural fluoride, water fluoridated through food supplements also diet is prepared in the house using the water and toothpaste and lotion mouth and some other products5. the highest concentrations are founding tea seafood spinach and gelatin, the least in citrus fruits, vegetables, eggs and milk6
Second: Absorption fluoride:
Fluoride is absorbed rapidly in the body and the absorption rate depends on fluoride solubility and acidity of the stomach. Fluoride7, which is not absorbed in the stomach, will be absorbed in the intestine for 30-60 minutes. Plasma after absorption will carry fluoride and distribute it throughout the body8 . Most of the fluoride secretion is eliminated by the kidneys in the urine and small amounts are eliminated by the sweat glands.
Third: Distribution and Retention:
Fluoride is distributed by plasma to the whole body and tissue. There is a convergence in the mineralization between them. About 99% of fluoride is located in mineralized tissues such as bone and teeth. The highest concentration of fluoride ate the surface next to tissue fluid suppling the fluoride.
The fluoride ion (F) is stored as an integral part of the crystal lattice of teeth and bones. Amount stored varies with the intake, the time of exposure, and the age and stage of the development of the individual. The teeth store small amounts, with highest levels on the tooth surface. Fluoride that accumulates in bone can be mobilized slowly from the skeleton due to the constant resorption and remodeling of bone. Once tooth enamel is fully matured, the fluoride deposited during development can be altered by cavitate dental caries, erosion, or mechanical abrasion9.
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Chapter 2: effect and benefit of fluoridation
1-Appearance of teeth
2- dental caries for primary and permanent teeth
3-Tooth loss and periodontal health
First appearance of teeth:
Teeth which have perfect or slightly higher level of fluoride appear white, shining, opaque, and without blemishes. When level is less the caries will start progression rapidly to attack the teeth and grow to make different type of problem and lesion10. When the level is slightly more than optimum, teeth may exhibit mild enamel fluorosis seen as white areas in bands or flecks. Without close scrutiny, such spots blend with the overall appearance. The majority of fluorosis today is mild and not considered an esthetic problem11.
Dental Caries: Primary Teeth
A Cochrane review on fluoridation for the prevention of dental caries, that dental caries a major public health problem in most countries, affecting 60% to 90% of school children, and that community water fluoridation is considered by health to be a key strategy in the prevention of dental caries12. From the 107 studies, they found that of water fluoridation resulted in reductions in dmft of 1.81 (a 35% reduction) and in DMFT of 1.16 (a 26% reduction) compared to the median control group mean values13. There were also increases in the percentage of caries-free children of 15% for the deciduous dentition and 14% for the permanent dentition. The major of studies (71%) were conducted prior to 1975 and the widespread introduction of the use of fluoride toothpaste14
With fluoridation from birth, the caries incidence is reduced up to 40% in the primary teeth.' The introduction of fluoridation into a community significantly increases the proportion of caries-free children and reduces the decayed, missing, and filled teeth (dmft/DMFT) scores when compared to areas that are non-fluoridated over the same time period.
For example, children aged 6-9 years in Newburgh, New York, had five times as many caries-free primary teeth present as did the children of Kingston, where fluoride was not present in the community drinking water15
Dental Caries: Permanent Teeth
Maximum benefit is seen with fluoridated water from birth. Estimates have shown the reduction in caries due to water fluoridation alone (factoring out other sources of topical fluoride) among adults of all ages is 27%16. The effects are similar to communities with optimum levels of natural fluoride in the water. Many more individuals are completely caries-free when fluoride is in the water.
Anterior teeth, particularly maxillary, receive more protection from fluoride than do posterior teeth. Anterior teeth are contacted by the drinking water as it passes into the mouth17. And progression Not only are the numbers of carious lesions reduced, but the caries rate is slowed Caries progression is also reduced in the surfaces that receive fluoride for the first time after eruption18.
Third: Tooth loss and periodontal health:
Gum disease is one of the two major dental diseases Which affect the population around the world at a high-level Prevalence rates19.It was observed that proliferation of periodontal disease is the largest in developing Countries from industrialized countries20.
The role of personal risk factors such as poor lifestyle Negative psychological and social conditions have been said to play an important role in the causes of adult gingivitis.
It prevents bone resorption by fluoride in a variety of model systems indicates May protect against the loss of alveolar bone in the gums Disease21. Fluoridated drinking water may affect periodontal disease through direct or indirect mechanisms. Direct effects may occur if fluoridation decreases the amount of adherence of plaque or if fluoresced teeth inhibit
plaque Fluoridation may also affect indirectly. on the periodontal tissue by reducing caries and the amount of restorative treatment fluoridation reduces interproximal caries, fewer restorations may be placed on smooth tooth surfaces, resulting in less subgingival calculus. Similarly, if fluoridation decreases interproximal restorations, this may reduce attachment loss, pocket depth and the number of interproximal bleeding sites. Fluoridation may also reduce the amount of recession from fillings placed on buccal surfaces22.