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Dental Fluorosis
Dental fluorosis is a common disorder, characterized by hypomineralization of tooth enamel caused by ingestion of excessive fluoride during enamel formation. It appears as a range of visual changes in enamel causing degrees of intrinsic tooth discoloration, and, in some cases, physical damage to the teeth. The severity of the condition is dependent on the dose, duration, and age of the individual during the exposure. The "very mild" (and most common) form of fluorosis, is characterized by small, opaque, "paper white" areas scattered irregularly over the tooth, covering less than 25% of the tooth surface. In the "mild" form of the disease, these mottled patches can involve up to half of the surface area of the teeth. When fluorosis is moderate, all of the surfaces of the teeth are mottled and teeth may be ground down and brown stains frequently "disfigure" the teeth. Severe fluorosis is characterized by brown discoloration and discrete or confluent pitting; brown stains are wid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dentistry
Dentistry, also known as dental medicine and oral medicine, is the branch of medicine focused on the teeth, gums, and mouth. It consists of the study, diagnosis, prevention, management, and treatment of diseases, disorders, and conditions of the mouth, most commonly focused on dentition (the development and arrangement of teeth) as well as the oral mucosa. Dentistry may also encompass other aspects of the craniofacial complex including the temporomandibular joint. The practitioner is called a dentist. The history of dentistry is almost as ancient as the history of humanity and civilization with the earliest evidence dating from 7000 BC to 5500 BC. Dentistry is thought to have been the first specialization in medicine which have gone on to develop its own accredited degree with its own specializations. Dentistry is often also understood to subsume the now largely defunct medical specialty of stomatology (the study of the mouth and its disorders and diseases) for which reas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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47, 47 or forty-seven may refer to: *47 (number) *47 BC *AD 47 *1947 * 2047 *'47 (brand), an American clothing brand * ''47'' (magazine), an American publication * 47 (song), a song by Sidhu Moose Wala *47, a song by New Found Glory from the album ''Not Without a Fight'' *"Forty Seven", a song by Karma to Burn from the album '' V'', 2011 * +47, the international calling code for Norway *4seven, a television channel *Agent 47, protagonist of the ''Hitman'' video game series *''47'', a young adult novel by Walter Mosley See also * List of highways numbered 47 * Channel 47 (other) * M47 (other), including "Model 47" (M47) * Forty-seven Ronin (other) * A47 (other) A47 may refer to: * Queen's Indian Defense, ''Encyclopaedia of Chess Openings'' code * Focke-Wulf A.47, a meteorological aircraft developed in Germany in 1931 ; roads * A47 road, a road connecting Birmingham and Lowestoft in England ... * Capital Steez {{number disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Veneer (dentistry)
In dentistry, a veneer is a layer of material placed over a tooth. Veneers can improve the aesthetics of a smile and protect the tooth's surface from damage. There are two main types of material used to fabricate a veneer: composite and dental porcelain. A composite veneer may be directly placed (built-up in the mouth), or indirectly fabricated by a dental technician in a dental lab, and later bonded to the tooth, typically using a resin cement. They are typically used for treatment of adolescent patients who will require a more permanent design once they are fully grown. The lifespan of a composite veneer is approximately four years. In contrast, a porcelain veneer may only be indirectly fabricated. A full veneer crown is described as "a restoration that covers all the coronal tooth surfaces (mesial, distal, facial, lingual and occlusal)". Laminate veneer, on the other hand, is a thin layer that covers only the surface of the tooth and is generally used for aesthetic purposes. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Composite Filling
Dental composite resins (better referred to as "resin-based composites" or simply "filled resins") are dental cements made of synthetic resins. Synthetic resins evolved as restorative materials since they were insoluble, of good tooth-like appearance, insensitive to dehydration, easy to manipulate and inexpensive. Composite resins are most commonly composed of Bis-GMA and other dimethacrylate monomers (TEGMA, UDMA, HDDMA), a filler material such as silica and in most applications, a photoinitiator. Dimethylglyoxime is also commonly added to achieve certain physical properties such as flow-ability. Further tailoring of physical properties is achieved by formulating unique concentrations of each constituent. Many studies have compared the lesser longevity of resin-based composite restorations to the longevity of silver-mercury amalgam restorations. Depending on the skill of the dentist, patient characteristics and the type and location of damage, composite restorations can have sim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enamel Microabrasion
Enamel microabrasion is a procedure in cosmetic dentistry used to improve the appearance of the teeth. Like tooth whitening it is used to remove discolorations of the tooth surface but microabrasion is both a mechanical and chemical procedure. History In the past, teeth with stains or other color changes were made to look better through the use of restorative materials, such as dental porcelain. These materials would create a thin veneer over the outer surface of the tooth. Although veneers looked better, these materials did not match the structure or characteristics of the tooth enamel and replacement was frequently needed. As far back as 1916, some researchers were advocating instead removing a thin layer of the outermost enamel to expose the (presumably) undamaged layer underneath. The first practical application of enamel microabrasion was developed by Theodore Croll and Richard Cavanaugh in 1986, who used a combination of weak hydrochloric acid and pumice to remove a few t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tooth Bleaching
Tooth whitening or tooth bleaching is the process of lightening the color of human teeth. Whitening is often desirable when teeth become yellowed over time for a number of reasons, and can be achieved by changing the intrinsic or extrinsic color of the tooth enamel. The chemical degradation of the chromogens within or on the tooth is termed as bleaching. Hydrogen peroxide () is the active ingredient most commonly used in whitening products and is delivered as either hydrogen peroxide or carbamide peroxide. Hydrogen peroxide is analogous to carbamide peroxide as it is released when the stable complex is in contact with water. When it diffuses into the tooth, hydrogen peroxide acts as an oxidising agent that breaks down to produce unstable free radicals. In the spaces between the inorganic salts in tooth enamel, these unstable free radicals attach to organic pigment molecules resulting in small, less heavily pigmented components. Reflecting less light, these smaller molecules creat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Defluoridation
Defluoridation is the downward adjustment of the level of fluoride in drinking water. Worldwide, fluoride is one of the most abundant anions present in groundwater. Fluoride is more present in groundwater than surface water mainly due to the leaching of minerals. Groundwater accounts for 98 percent of the earth's potable water. An excess of fluoride in drinking water causes dental fluorosis and skeletal fluorosis. The World Health Organization has recommended a guideline value of 1.5 mg/L as the concentration above which dental fluorosis is likely. Fluorosis is endemic in more than 20 developed and developing nations. History Fluorosis was not identified as a problem until relatively recently. Few attempts to defluoridate water came before the 20th century. In the 1930s, several nations began to investigate fluoride's negative effects and how best to remove it. An aluminum and sand filter that removes fluorine from water was devised by Dr. S. P. Kramer in 1933; in 1945, M. Ke ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluorapatite
Fluorapatite, often with the alternate spelling of fluoroapatite, is a phosphate mineral with the formula Ca5(PO4)3F (calcium fluorophosphate). Fluorapatite is a hard crystalline solid. Although samples can have various color (green, brown, blue, yellow, violet, or colorless), the pure mineral is colorless, as expected for a material lacking transition metals. Along with hydroxylapatite, it can be a component of tooth enamel, but for industrial use both minerals are mined in the form of phosphate rock, whose usual mineral composition is primarily fluorapatite but often with significant amounts of the other. Fluorapatite crystallizes in a hexagonal crystal system. It is often combined as a solid solution with hydroxylapatite (Ca5(PO4)3OH or Ca10(PO4)6(OH)2) in biological matrices. Chlorapatite (Ca5(PO4)3Cl) is another related structure. Industrially, the mineral is an important source of both phosphoric and hydrofluoric acids. Fluorapatite as a mineral is the most common p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydroxyapatite
Hydroxyapatite, also called hydroxylapatite (HA), is a naturally occurring mineral form of calcium apatite with the formula Ca5(PO4)3(OH), but it is usually written Ca10(PO4)6(OH)2 to denote that the crystal unit cell comprises two entities. Hydroxyapatite is the hydroxyl endmember of the complex apatite group. The OH− ion can be replaced by fluoride, chloride or carbonate, producing fluorapatite or chlorapatite. It crystallizes in the hexagonal crystal system. Pure hydroxyapatite powder is white. Naturally occurring apatites can, however, also have brown, yellow, or green colorations, comparable to the discolorations of dental fluorosis. Up to 50% by volume and 70% by weight of human bone is a modified form of hydroxyapatite, known as bone mineral. Carbonated calcium-deficient hydroxyapatite is the main mineral of which dental enamel and dentin are composed. Hydroxyapatite crystals are also found in pathological calcifications such as those found in breast tumors, as w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protease
A protease (also called a peptidase, proteinase, or proteolytic enzyme) is an enzyme that catalyzes (increases reaction rate or "speeds up") proteolysis, breaking down proteins into smaller polypeptides or single amino acids, and spurring the formation of new protein products. They do this by cleaving the peptide bonds within proteins by hydrolysis, a reaction where water breaks bonds. Proteases are involved in many biological functions, including digestion of ingested proteins, protein catabolism (breakdown of old proteins), and cell signaling. In the absence of functional accelerants, proteolysis would be very slow, taking hundreds of years. Proteases can be found in all forms of life and viruses. They have independently evolved multiple times, and different classes of protease can perform the same reaction by completely different catalytic mechanisms. Hierarchy of proteases Based on catalytic residue Proteases can be classified into seven broad groups: * Serine protease ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amelogenin
Amelogenins are a group of protein isoforms produced by alternative splicing or proteolysis from the ''AMELX'' gene, on the X chromosome, and also the ''AMELY'' gene in males, on the Y chromosome. They are involved in amelogenesis, the development of enamel. Amelogenins are type of extracellular matrix protein, which, together with ameloblastins, enamelins and tuftelins, direct the mineralization of enamel to form a highly organized matrix of rods, interrod crystal and proteins. Although the precise role of amelogenin(s) in regulating the mineralization process is unknown, it is known that amelogenins are abundant during amelogenesis. Developing human enamel contains about 70% protein, 90% of which are amelogenins. Function Amelogenins are believed to be involved in the organizing of enamel rods during tooth development. The latest research indicates that these proteins regulate the initiation and growth of hydroxyapatite crystals during the mineralization of enamel. In add ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Health And Nutrition Examination Survey
The National Health and Nutrition Examination Survey (NHANES) is a survey research program conducted by the National Center for Health Statistics (NCHS) to assess the health and nutritional status of adults and children in the United States, and to track changes over time. The survey combines interviews, physical examinations and laboratory tests. The NHANES interview includes demographic, socioeconomic, dietary, and health-related questions. The examination component consists of medical, dental, and physiological measurements, as well as laboratory tests administered by medical personnel. The first NHANES was conducted in 1971, and in 1999 the surveys became an annual event; the first report on the topic was published in 2001. NHANES findings are used to determine the prevalence of major diseases and risk factors for diseases. Information is used to assess nutritional status and its association with health promotion and disease prevention. NHANES findings are also the basis for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
