Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Fluoride Protection from Caries

The presence of even one fluoride ion in the crystal slows the transformation to amorphous calcium monohydrogen phosphate. Thus, in the presence of fluoride (e.g., after using fluoridated toothpastes), fluoroapatite forms at the tooth surface and reduces the rate of caries development. The increased fluoride concentration at the tooth surface also inhibits lactate production. These observations explain why cleaning the teeth with fluoridated toothpaste prevent caries. Cleaning the teeth exposes the apatite at the enamel surface. In the absence of fluoride, there is no protection because the biofilm forms within a few [Pg.291]

Before fluoride was added to toothpastes (1950-1970), fluoridated water provided considerable protection from caries, but now that virtually all toothpastes are fluoridated, some have questioned the need for water fluoridation. Yet carefully controlled studies in Scotland, where public pressure to remove fluoride from the water supply has been extremely strong, indicate a marked increase in caries despite the continued use of fluoridated toothpaste (see Sect. 16.3.2). Fluoride toothpaste-mediated protection from caries is dependent on oral hygiene efficacy, whereas protection from caries by fluoride in the water supply appears independent of oral hygiene. Protection from caries by artificial fluoridation of water supplies and fluoridated toothpaste is independent and additive. [Pg.292]

In the USA, water fluoridation became widely available after 1955 and fluoridated toothpastes after 1975. In 1954, few locations had naturally or artificially fluoridated drinking water and fluoridated toothpastes did not exist and the mean DMFT in US 12-13-year-old children was about 7. By 2004, according to the National Health Nutrition Examination Survey, most locations had fluoridated water and fluoridated toothpaste and the mean DMFT in 11-15-year-old children had fallen from 8.0 in the mid-1950s to less than 2.0. [Pg.292]


In the USA, water fluoridation became widely available after 1955 and fluoridated toothpastes after 1975 and caries in adolescent children has decreased by 66%. The effects of fluoride on caries are topical from the surface to the interior. Water fluoridation ensures small amounts of fluoride throughout a tooth and fluoridated toothpaste enhances the fluoride concentration at the tooth surface. Protection from caries by artificial fluoridation of water supplies and fluoridated toothpaste is cumulative. Investigations as to how fluoridation protects from caries has identified three mechanisms of caries protection (1) inhibition of demineralization, (2) enhancement of remineralization, and (3) inhibition of bacterial enolase activity reducing lactate production from ingested carbohydrates. Fluoride has little effect on bacterial growth, and gives no direct protection from gingivitis, periodontitis, or osteoporosis... [Pg.294]

This chapter describes how individuals with severe enamel fluorosis (mottled tooth enamel) became associated with fluoride in the public water supply and protection from dental caries. A comparison of caries experience with the fluoride content of public water supplies and enamel fluorosis in adolescents indicated that 1 pg fluoride/mL (1 part/million) in the water provides caries protection with minimal enamel fluorosis (sect. 1). One mechanism is the spontaneous isomorphic replacement of apatite s hydroxide anions with fluoride, which reduces enamel solubility. A second is fluoride-mediated inhibition of enolase, which retards bacterial acid production at teeth surfaces. These findings led to the use of fluoride in toothpastes, which provides better protection from caries at tooth surfaces than water fluoridation alone (sect. 2). The chapter concludes with a discussion of potentially harmful effects of fluoride ingestion (sect. 3). [Pg.285]

Apatites must undergo a solid-state transition to amorphous calcium phosphate before they can dissolve and the spontaneous replacement of hydroxide with fluoride ions slows the rate at which this transition occurs (Fig. 16.6b). Conversely, as an acid environment becomes more alkaline, fluoride ions promote the precipitation and crystallization of amorphous calcium monohydrogen phosphate/calcium fluoride into fluoro- and difluoro-apatites faster than amorphous calcium phosphate would crystallize into hydroxyapatite. Thus, fluoride ions have two effects on enamel that protect from caries they slow enamel dissolution in lactic acid and promote its re-precipitation and crystallization when the lactic acid is neutralized. [Pg.292]

A second mechanism of protection from caries is the incorporation of fluoride into bacterial biofilms where it inhibits enolase. Enolase catalyzes the production of phospho-enolpyruvate, the precursor of lactate in glycolysis, from 2-phosphoglycerate during glycolysis (Fig. 16.7 - see also Fig. 1.7). In addition, oral bacterial uptake of mono- and disaccharides mostly utilizes the phosphoenolpyruvate transport system to transfer them into the cytosol (Sect. 15.2.2). Fluoride therefore inhibits not only lactic acid production, but also the phosphoenolpyruvate transport system-mediated uptake of saccharide substrates. In short, fluoride inhibits saccharolytic fermentation by many oral bacteria. [Pg.293]

Four healthy young adult males receiving either 0, 1,3, 5 or 10 mg fluoride by mouth daily over each of 5 successive weeks gave urinary fluoride rates that were virtually a linear function of dose [190]. For the different doses of fluoride, urine fluoride recovery rates varied from 20.0 to 31.3 per cent (mean = 25.3 per cent) [190]. Humans having fluoridated salt (250 mg F kg ) in their diet appear from their urinary fluoride to have about the same protection from caries, as with water fluoridation [247]. [Pg.73]

Aluminium ions released from the dental silicate cement are also absorbed by hydroxyapatite and have a similar beneficial effect to that of fluoride (Halse Hals, 1976 Putt Kleber, 1985). Thus, the dental silicate cement confers protection against caries (dental decay) on surrounding tooth material. [Pg.258]

Remineralisation occurs when partly dissolved crystals are induced to grow by precipitation of the mineral-forming ions Ca + and POl". This is a natural process that occurs as a result of the concentration of these ions in saliva [23] and it serves to oppose the demineralising effects of caries. The processes involved are complex [24] and involve dynamic activity at the interface between the tooth, the saliva, the pellicle and the plaque. Fluoride plays a role in enhancing these processes, and though this is not the only contribution that fluoride makes to protect the tooth from caries, it is nonetheless an important one. [Pg.338]

Fluorine in Plants and Animals, In 1802 Domenico Pini Morichini discovered the presence of fluorine in fossil ivory (157). He later detected it in the enamel of the teeth, and Berzelius soon confirmed the discovery and showed that fluorine is also a normal constituent of bone (158,159, 165). The presence of excessive amounts of fluoride in drinking water causes the well-known mottling of the enamel of children s teeth (160), but small amounts of fluoride protect the teeth from dental caries (161). [Pg.770]

Dental plaque also tends to concentrate fluoride. This could increase possible antienzymatic activity. Some caries protection from this may be expected. Additionally, studies have suggested that topical application of fluoride may also reduce smooth surface plaque, with a resulting beneficial effect on the periodontal tissues. [Pg.891]

Fluorine is present on earth only as fluoride, a negatively charged anion that is especially important in dentistry because of its ability to mediate protection from dental caries (Chapter 16, section 16.2.1.). Although metabolites of chlorine and iodine are ubiquitous, few biological products contain fluoride because of its tight hydration shell. The few enzymes that utilize fluoride as a cofactor must overcome an exceptionally high desolvation energy barrier. [Pg.6]

Fluoride release from glass-ionomers changes in low pH environments, and increases compared with release in neutral conditions [102]. In addition, release at low pH is associated with an increase in pH of the external medium, a process that has been termed buffering. The abihty to buffer acids such as lactic acid in active caries may be clinically beneficial and is a potential mechanism for the protection of the tooth from further tooth decay [103]. [Pg.121]

Ytterbium is a soft, malleable metal with a bright, silvery luster. It is fairly unreactive but needs to be kept in closed containers to protect it from air and moisture. Ytterbium fluoride is non-toxic and inert. It is not transparent to X-rays. Because of that the compound has been tested as an additive to composite dental plastic fillings. Traces of fluoride ions are continuously set free, giving protection against caries. [Pg.424]

Stannous fluoride is used in toothpastes and dental rinses to protect tooth enamel from attack by bacteria—cavities (also known as dental caries). It was the first fluoride used for that purpose, in the toothpaste Crest. [Pg.243]

It is superior to the zinc phosphate cement for bonding orthodontic bands to teeth (Clark, Phillips Norman, 1977). It has greater durability and there is less decalcification in adjacent tooth enamel. This latter beneficial effect must arise from the release of fluoride which is absorbed by the enamel, so protecting it in a clinical situation where caries-produdng debris and plaque accumulate. [Pg.265]

Fluorine is available to humans, plants and animals mainly in the form of fluoride ion (F ). Body fluoride status depends on numerous factors, including the total amount of fluoride ingested daily, its bioavailability and metabolism. The adequate intake (Al) of fluoride from all sources is set by the Standing Committee on the Scientific Evaluation of the Dietary Reference Intakes at 0.05 mg/day/kg body weight this intake is recommended for all ages above 6 months, because it confers a high level of protection against dental caries and is not associated with any known unwanted health effects [8]. [Pg.489]

Dental caries have been prevented when fluoride tablets were administered in a school-based program. After two or more years of fluoride ingestion, protection against dental caries ranged from 20 0%. In an extended trial of fluoride tablets reported in the literature, there was a 36% reduction in dental caries after 8 years. ... [Pg.892]

As with glass-ionomer cements, flnoride release from polyacid-modified composite resins is snstained for long periods of time [23] and is enhanced by placing the polyacid-modified composite resin in acidic storage media [25,36]. This property has been snggested to be beneficial in the case of resin-modified glass-ionomers [37], since it wonld lead to enhanced release of protective fluoride ion under the very conditions that promote dental caries. A similar argnment can be advanced for polyacid-modified composite resins, and it may be that this ability to release extra fluoride under conditions of low pH is beneficial clinically. [Pg.78]

This refers to the addition of trace amounts (0.5 to 1.0 parts per million) of fluoride, usually as the sodium salt, to drinking water, for the purpose of providing protection against dental caries. This has proved to be a safe, economical, and efficient way in which to reduce tooth decay—a highly important public health measure in areas where natural water supplies do not contain sufficient fluoride. Extensive medical and public health studies have clearly demonstrated the safety and nutritional advantages that result from fluoridation of water supplies. In communities in which fluoridation has been introduced, the incidence of tooth decay in children has been decreased by 50% or more. [Pg.371]


See other pages where Fluoride Protection from Caries is mentioned: [Pg.291]    [Pg.291]    [Pg.292]    [Pg.293]    [Pg.291]    [Pg.291]    [Pg.292]    [Pg.293]    [Pg.535]    [Pg.114]    [Pg.283]    [Pg.792]    [Pg.167]    [Pg.538]    [Pg.895]    [Pg.261]    [Pg.282]    [Pg.792]    [Pg.42]    [Pg.453]   


SEARCH



Caries

How Fluoride Protects from Caries

Protection from

© 2024 chempedia.info