Tooth enamel is the hardest and most highly mineralized substance of the body,^[1] and with dentin, cementum, and dental pulp is one of the four major tissues which make up the tooth. It is the normally visible dental tissue of a tooth and must be supported by underlying dentin. Ninety-six percent of enamel consists of mineral, with water and organic material composing the rest.^[2] The normal color of enamel varies from light yellow to grayish white. At the edges of teeth where there is no dentin underlying the enamel, the color sometimes has a slightly blue tone. Since enamel is semitranslucent, the color of dentin and any restorative dental material underneath the enamel strongly affects the appearance of a tooth. Enamel varies in thickness over the surface of the tooth and is often thickest at the cusp, up to 2.5 mm, and thinnest at its border, which is seen clinically as the cementoenamel junction (CEJ).^[3] Wikipedia does not have an article with this exact name. ... Wikipedia does not have an article with this exact name. ... Parts of a tooth, including dentin Dentin (BE: dentine) is a calcified tissue of the body, and along with enamel, cementum, and pulp is one of the four major components of teeth. ... Cementum is a specialized bony substance covering the root of a tooth. ... The dental pulp is the part in the center of a tooth made up of living soft tissue and cells called odontoblasts and others. ... Teeth redirects here. ... In optics, transparency is the property of being transparent, or allowing light to pass. ... Variation in the physical appearance of humans is believed by anthropologists to be an important factor in the development of personality and social relations in particular physical attractiveness. ... A cusp is an occlusal or incisal eminance on a tooth. ... The cementoenamel junction, frequently abbreviated as the CEJ, is an anatomical landmark identified on a tooth. ...

Enamel's primary mineral is hydroxylapatite, which is a crystalline calcium phosphate.^[4] The large amount of minerals in enamel accounts not only for its strength but also for its brittleness.^[5] Tooth enamel is the hardest substance in the human body, ranking a 5 on Mohs hardness scale. Dentin, less mineralized and less brittle, 3-4 in hardness, compensates for enamel and is necessary as a support.^[4] Hydroxylapatite is a naturally occurring form of calcium apatite with the formula Ca5(PO4)3(OH), but is usually written Ca10(PO4)6(OH)2 to denote that the crystal unit cell comprises two molecules. ... For other uses, see Crystal (disambiguation). ... Calcium phosphate is the name given to a family of minerals containing calcium ions (Ca2+) together with orthophosphates (PO43-), metaphosphates or pyrophosphates (P2O74-) and occasionally hydrogen or hydroxide ions. ... The Mohs scale of mineral hardness characterizes the scratch resistance of various minerals through the ability of a harder material to scratch a softer material. ...

Unlike dentin and bone, enamel does not contain collagen. Instead, it has two unique classes of proteins called amelogenins and enamelins. While the role of these proteins is not fully understood, it is believed that they aid in the development of enamel by serving as a framework support, among other functions.^[6] This article is about the skeletal organs. ... Tropocollagen triple helix. ... A representation of the 3D structure of myoglobin showing coloured alpha helices. ... Amelogenin is a gene-specific, low-molecular-weight protein found in tooth enamel, and it belongs to a family of extracellular matrix (ECM) proteins. ... Enamelin is a protein found at low concentration in developing tooth enameltooth enamel. ...

Structure

The basic unit of enamel is called an enamel rod.^[4] Measuring 4 μm - 8 μm in diameter an enamel rod, formerly called an enamel prism, is a tightly packed mass of hydroxyapatite crystals in an organized pattern.^[1] In cross section, it is best compared to a keyhole, with the top, or head, oriented toward the crown of the tooth, and the bottom, or tail, oriented toward the root of the tooth. Wikipedia does not have an article with this exact name. ... Wikipedia does not have an article with this exact name. ... An Enamel rod is the basic unit of enamel. ...

The arrangement of the crystals within each enamel rod is highly complex. Both ameloblasts (the cells which initiate enamel formation) and Tomes' processes affect the crystals' pattern. Enamel crystals in the head of the enamel rod are oriented parallel to the long axis of the rod.^[3][1] When found in the tail of the enamel rod, the crystals' orientation diverges slightly from the long axis.^[1] After dentinogenesis begins preameloblasts differentiates into ameloblasts which deposit enamel. ... Tomes processes are a histologic landmark identified on an ameloblast. ...

The arrangement of enamel rods is understood more clearly than their internal structure. Enamel rods are found in rows along the tooth, and within each row, the long axis of the enamel rod is generally perpendicular to the underlying dentin.^[7] In permanent teeth, the enamel rods near the cementoenamel junction (CEJ) tilt slightly toward the root of the tooth. Understanding enamel orientation is very important in restorative dentistry, because enamel unsupported by underlying dentin is prone to fracture.^[7]

The area around the enamel rod is known as interrod enamel. Interrod enamel has the same composition as enamel rod, however a histologic distinction is made between the two because crystal orientation is different in each.^[3] The border where the crystals of enamel rods and crystals of interrod enamel meet is called the rod sheath.^[8] Interrod enamel is histologically identified on microscopic views of tooth enamel. ... A thin section of lung tissue stained with hematoxylin and eosin. ... The rod sheath is an area identified in histologic sections of a tooth. ...

Striae of Retzius are stripes that appear on enamel when viewed microscopically in cross section.^[7] Formed from changes in diameter of Tomes’ processes, these stripes demonstrate the growth of enamel, similar to the annual rings on a tree. Perikymata are shallow furrows where the striae of Retzius end.^[9] Darker than the other stripes, the neonatal line is a stripe that separates enamel formed before and after birth.^[10] The striae of Retzius are incremental growth lines seen in enamel and are results of enamels development. ... Perikymata (Greek plural of: perikyma) are the pits around the long microscopical prisms of tooth enamel. ... The neonatal line is a particular band of incremental growth lines seen in histologic sections of a tooth. ...

Gnarled enamel is found at the cusps of teeth.^[11] Its twisted appearance results from the orientation of enamel rods and the rows in which they lie. Gnarled enamel is a description of enamel seen in histologic sections of a tooth underneath a cusp. ...

Development

Histologic slide showing a developing tooth. The mouth would be in the area of space at the top of the picture.

Enamel formation is part of the overall process of tooth development. When the tissues of the developing tooth are seen under a microscope, different cellular aggregations can be identified, including structures known as the enamel organ, dental lamina, and dental papilla.^[12] The generally recognized stages of tooth development are the bud stage, cap stage, bell stage, and crown, or calcification, stage. Enamel formation is first seen in the crown stage. Image File history File linksMetadata Download high resolution version (897x1219, 429 KB) Histology of developing tooth with enamel organ, dental lamina, and dental papilla labeled. ... Image File history File linksMetadata Download high resolution version (897x1219, 429 KB) Histology of developing tooth with enamel organ, dental lamina, and dental papilla labeled. ... Radiograph of lower right (from left to right) third, second, and first molars in different stages of development. ... The enamel organ, also known as dental organ, is a cellular aggregation seen in histologic sections of a developing tooth. ... The dental lamina is a band of epithelial tissue seen in histologic sections of a developing tooth. ... The dental papilla is a condensation of ectomesenchymal cells called odontoblasts, seen in histologic sections of a developing tooth. ...

Amelogenesis, or enamel formation, occurs after the first establishment of dentin, via cells known as ameloblasts. Human enamel forms at a rate of around 4 μm per day, beginning at the future location of cusps, around the third or fourth month of pregnancy.^[7] As in all human processes, the creation of enamel is complex, but can generally be divided into two stages.^[13] The first stage, called the secretory stage, involves proteins and an organic matrix forming a partially mineralized enamel. The second stage, called the maturation stage, completes enamel mineralization. Amelogenesis is the formation of enamel on teeth and occurs during the Apposition stage of tooth development after dentinogenesis, which is the formation of dentin. ... This article is about the unit of length. ...

Histologic slide showing enamel formation.

In the secretory stage, ameloblasts are polarized columnar cells. In the rough endoplasmic reticulum of these cells, enamel proteins are released into the surrounding area and contribute to what is known as the enamel matrix, which is then partially mineralized by the enzyme alkaline phosphatase.^[14] When this first layer is formed, the ameloblasts move away from the dentin, allowing for the development of Tomes’ processes at the apical pole of the cell. Enamel formation continues around the adjoining ameloblasts, resulting in a walled area, or pit, that houses a Tomes’ process, and also around the end of each Tomes’ process, resulting in a deposition of enamel matrix inside of each pit.^[15] The matrix within the pit will eventually become an enamel rod, and the walls will eventually become interrod enamel. The only distinguishing factor between the two is the orientation of the calcium phosphate crystals. Image File history File linksMetadata Download high resolution version (904x936, 391 KB) Histology of developing tooth with enamel, dentin, ameloblasts, and odontoblasts labeled. ... Image File history File linksMetadata Download high resolution version (904x936, 391 KB) Histology of developing tooth with enamel, dentin, ameloblasts, and odontoblasts labeled. ... Drawing of the structure of cork as it appeared under the microscope to Robert Hooke from Micrographia which is the origin of the word cell being used to describe the smallest unit of a living organism Cells in culture, stained for keratin (red) and DNA (green) The cell is the... The endoplasmic reticulum or ER (endoplasmic means within the cytoplasm, reticulum means little net) is an organelle found in all eukaryotic cells. ... Ball and stick model of alkaline phosphatase Alkaline phosphatase (ALP) (EC 3. ...

In the maturation stage, the ameloblasts transport substances used in the formation of enamel. Histologically, the most notable aspect of this phase is that these cells become striated, or have a ruffled border.^[14] These signs demonstrate that the ameloblasts have changed their function from production, as in the secretory stage, to transportation. Proteins used for the final mineralization process compose most of the transported material. The noteworthy proteins involved are amelogenins, ameloblastins, enamelins, and tuftelins.^[16] During this process, amelogenins and ameloblastins are removed after use, leaving enamelins and tuftelin in the enamel.^[17] By the end of this stage, the enamel has completed its mineralization. Amelogenin is a gene-specific, low-molecular-weight protein found in tooth enamel, and it belongs to a family of extracellular matrix (ECM) proteins. ... Ameloblastin, also known as amelin, is a gene-specific protein found in tooth enamel. ... Enamelin is a protein found at low concentration in developing tooth enameltooth enamel. ... Tuftelin is an acidic phosphorylated glycoprotein found in tooth enamel. ...

At some point before the tooth erupts into the mouth, but after the maturation stage, the ameloblasts are broken down. Consequently, enamel, unlike many other tissues of the body, has no way to regenerate itself.^[18] After destruction of enamel from decay or injury, neither the body nor a dentist can restore the enamel tissue. Enamel can be affected further by non-pathologic processes. The discoloration of teeth over time can result from exposure to substances such as tobacco, coffee, and tea.^[19] This is partly due to material building up in the enamel, but is also an effect of the underlying dentin becoming sclerotic.^[20] As a result, tooth color gradually darkens with age. Additionally, enamel becomes less permeable to fluids, less soluble to acid, and contains less water.^[20] Shredded tobacco leaf for pipe smoking Tobacco can also be pressed into plugs and sliced into flakes Tobacco is an agricultural product processed from the fresh leaves of plants in the genus Nicotiana. ... For other uses, see Coffee (disambiguation). ... For other uses, see Tea (disambiguation). ...

Destruction

Destruction of enamel by cervical decay from dental caries.

The high mineral content of enamel, which makes this tissue the hardest in the human body, also makes it susceptible to a demineralization process which often occurs as dental caries, otherwise known as cavities.^[12] Demineralization occurs for several reasons, but the most important cause of tooth decay is the ingestion of sugars. Tooth cavities are caused when acids dissolve tooth enamel:^[22] Image File history File links Download high-resolution version (312x651, 242 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Tooth enamel Dental caries Wikipedia:Graphic Lab/Images to improve ... Image File history File links Download high-resolution version (312x651, 242 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Tooth enamel Dental caries Wikipedia:Graphic Lab/Images to improve ...

Ca₁₀(PO₄)₆(OH)₂(s) + 8H⁺(aq) → 10Ca²⁺(aq) + 6HPO₄^2-(aq) + 2H₂O(l)

Sugars from candies, soft drinks, and even fruit juices play a significant role in tooth decay, and consequently in enamel destruction. The mouth contains a great number and variety of bacteria, and when sucrose, the most common of sugars, coats the surface of the mouth, some intraoral bacteria interact with it and form lactic acid, which decreases the pH in the mouth.^[23] Then, the hydroxylapatite crystals of enamel demineralize, allowing for greater bacterial invasion deeper into the tooth. The most important bacterium involved with tooth decay is Streptococcus mutans, but the number and type of bacteria varies with the progress of tooth destruction.^[23] For other uses, see Candy (disambiguation). ... A soft drink is a drink that contains no alcohol. ... For other uses, see Juice (disambiguation). ... Phyla Actinobacteria Aquificae Chlamydiae Bacteroidetes/Chlorobi Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Lentisphaerae Nitrospirae Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Verrucomicrobia Bacteria (singular: bacterium) are unicellular microorganisms. ... Flash point N/A Except where noted otherwise, data are given for materials in their standard state (at 25 Â°C, 100 kPa) Infobox disclaimer and references Sucrose (common name: table sugar, also called saccharose) is a disaccharide (glucose + fructose) with the molecular formula C12H22O11. ... For the production of milk by mammals, see Lactation. ... Binomial name Streptococcus mutans Clarke 1924 Streptococcus mutans is a Gram-positive, facultatively anaerobic bacteria commonly found in the human oral cavity and is a significant contributor to tooth decay. ...

Furthermore, tooth morphology dictates that the most common site for the initiation of dental caries is in the deep grooves, pits, and fissures of enamel. This is expected because these locations are impossible to reach with a toothbrush and allow for bacteria to reside there. When demineralization of enamel occurs, a dentist can use a sharp instrument, such as a dental explorer, and "feel a stick" at the location of the decay. As enamel continues to become less mineralized and is unable to prevent the encroachment of bacteria, the underlying dentin becomes affected as well. When dentin, which normally supports enamel, is destroyed by a physiologic condition or by decay, enamel is unable to compensate for its brittleness and breaks away from the tooth easily. A No. ...

The effects of bruxism on an anterior tooth, revealing the dentin and pulp which are normally hidden by enamel.

The extent to which tooth decay is likely, known as cariogenicity, depends on factors such as how long the sugar remains in the mouth. Contrary to common belief, it is not the amount of sugar ingested but the frequency of sugar ingestion that is the most important factor in the causation of tooth decay.^[24] When the pH in the mouth initially decreases from the ingestion of sugars, the enamel is demineralized and left vulnerable for about 30 minutes. Eating a greater quantity of sugar in one sitting does not increase the time of demineralization. Similarly, eating a lesser quantity of sugar in one sitting does not decrease the time of demineralization. Thus, eating a great quantity of sugar at one time in the day is less detrimental than is a very small quantity ingested in many intervals throughout the day. For example, in terms of oral health, it is better to eat a single dessert at dinner time than to snack on a bag of candy throughout the day. Wikipedia does not have an article with this exact name. ... Wikipedia does not have an article with this exact name. ... Caries is a progressive destruction of any kind of bone structure, including the skull, the ribs and other bones. ... Not to be confused with Desert. ... For other uses, see Candy (disambiguation). ...

In addition to bacterial invasion, enamel is also susceptible to other destructive forces. Bruxism, also known as clenching of or grinding on teeth, destroys enamel very quickly. The wear rate of enamel, called attrition, is 8 micrometers a year from normal factors. A common misconception is that enamel wears away mostly from chewing, but actually teeth rarely touch during chewing. Furthermore, normal tooth contact is compensated physiologically by the periodontal ligaments (pdl) and the arrangement of dental occlusion. The truly destructive forces are the parafunctional movements, as found in bruxism, which can cause irreversible damage to the enamel. A profile of a smile, exhibiting significant wear, especially on the maxillary incisors. ... Attrition is the loss of tooth structure due to by mechanical forces from opposing teeth. ... // Headline text The periodontal ligaments are considered part of the periodontium, as they are supporting tissue of a tooth. ... Occlusion is the relationship between the maxillary and mandibular teeth that exists when they approach each other, as occurs during chewing or at rest. ...

Other nonbacterial processes of enamel destruction include abrasion (involving foreign elements, such as toothbrushes), erosion (involving chemical processes, such as lemon juice), and possibly abfraction (involving compressive and tensile forces).^[25] Abrasion is the loss of tooth structure by mechanical forces from a foreign element. ... Erosion is the loss of tooth structure due to chemical dissolution by acids not of bacterial origin. ... Abfraction is the loss of tooth structure from flexural forces. ...

Oral hygiene and fluoride

Main article: Oral hygiene

Considering the vulnerability of enamel to demineralization and the daily menace of sugar ingestion, prevention of tooth decay is the best way to maintain the health of teeth. Most countries have wide use of toothbrushes, which can reduce the number of bacteria and food particles on enamel. Some isolated societies do not have access to toothbrushes, but it is common for those people to use other objects, such as sticks, to clean their teeth. In between two adjacent teeth, floss is used to wipe the enamel surfaces free of plaque and food particles to discourage bacterial growth. Although neither floss nor toothbrushes can penetrate the deep grooves and pits of enamel, good general oral health habits can usually prevent enough bacterial growth to keep tooth decay from starting. Oral hygiene is the practice of keeping the mouth clean in order to prevent cavities (dental caries), gingivitis, periodontitis, bad breath (halitosis), and other dental disorders. ... Three toothbrushes The toothbrush is an instrument used to clean teeth, consisting of a small brush on a handle. ... Dental hygienist flossing a patients teeth Dental floss is either a bundle of thin nylon filaments or a plastic (teflon or polyethylene) ribbon used to remove food and dental plaque from teeth. ... Improper removal of plaque caused a build up of calculus (dark yellow colour) near the gums on almost all the teeth. ...

Common dentistry trays filled with fluoride.

These methods of oral hygiene have been helped greatly by the use of fluoride. Fluoride can be found in many locations naturally, such as the ocean and other water sources. Consequently, many seafood dishes contain fluoride. The recommended dosage of fluoride in drinking water is 1 part per million (ppm).^[26] Fluoride helps prevent dental decay by binding to the hydroxylapatite crystals in enamel.^[27] The incorporated fluoride makes enamel more resistant to demineralization and, thus, resistant to decay.^[23] Fluoride therapy is used to help teeth prevent dental decay. Image File history File links Download high resolution version (2024x1215, 490 KB) Picture taken at the University of TN Dental School in Memphis, TN of a maxillary and mandibular tray with fluoride. ... Image File history File links Download high resolution version (2024x1215, 490 KB) Picture taken at the University of TN Dental School in Memphis, TN of a maxillary and mandibular tray with fluoride. ... Oral hygiene is the practice of keeping the mouth clean in order to prevent cavities (dental caries), gingivitis, periodontitis, bad breath (halitosis), and other dental disorders. ... Fluoride is the ionic form of fluorine. ... Tap water Mineral Water Drinking water is water that is intended to be ingested through drinking by humans. ... Parts per million (ppm) is a measure of concentration that is used where low levels of concentration are significant. ... Fluoride therapy is the delivery of fluoride to the teeth topically or systemically, which is designed to prevent tooth decay (dental caries) which results in cavities. ...

Many groups of people have spoken out against fluoridated drinking water. One example used by these advocates is the damage fluoride can do as fluorosis. Fluorosis is a condition resulting from the overexposure to fluoride, especially between the ages of 6 months to 5 years, and appears as mottled enamel.^[28] Consequently, the teeth look unsightly and, indeed, the incidence of dental decay in those teeth is very small. However, it is important to note that most substances, even beneficial ones, are detrimental when taken in extreme doses. Where fluoride is found naturally in high concentrations, filters are often used to decrease the amount of fluoride in water. For this reason, codes have been developed by dental professionals to limit the amount of fluoride a person should take.^[29] These codes are supported by the American Dental Association and the American Academy of Pediatric Dentistry. The acute toxic dose of fluoride is ~5 mg/kg of body weight. Furthermore, whereas topical fluoride, found in toothpaste and mouthwashes, does not cause fluorosis, its effects are also less pervasive and not as long-lasting as those of systemic fluoride, such as when drinking fluorinated water.^[30] For instance, all of a tooth's enamel gains the benefits of fluoride when it is ingested systemically, through fluoridated water or salt fluoridation (a common alternative in Europe). Only some of the outer surfaces of enamel can be reached by topical fluoride. Thus, despite fluoridation's detractors, most dental health care professionals and organizations agree that the inclusion of fluoride in public water has been one of the most effective methods of decreasing the prevalence of tooth decay. Water fluoridation is the practice of adding fluoride compounds to water with the intended purpose of reducing tooth decay in the general population. ... Picture of a mild case of fluorosis. ...

Effects of dental procedures

An X-ray showing enamel and dentin replaced by an amalgam restoration.

Image File history File links own image (Amalgam filling in tooth) Bernard bill5 00:24, 8 Jan 2005 (UTC) File links The following pages link to this file: Tooth enamel User:SEWilco/Sandbox ... Image File history File links own image (Amalgam filling in tooth) Bernard bill5 00:24, 8 Jan 2005 (UTC) File links The following pages link to this file: Tooth enamel User:SEWilco/Sandbox ...

Dental restorations

Most dental restorations involve the removal of enamel. Frequently, the purpose of removal is to gain access to the underlying decay in the dentin or inflammation in the pulp. This is typically the case in amalgam restorations and endodontic treatment. A dental restoration or dental filling is a dental restorative material used artificially to restore the function, integrity and morphology of missing tooth structure. ... The dental pulp is the part in the center of a tooth made up of living soft tissue and cells called odontoblasts and others. ... This article is about mixtures (alloys) of mercury with other elements. ... For the operation, see endodontic therapy. ...

Nonetheless, enamel can sometimes be removed before there is any decay present. The most popular example is the dental sealant. The process of placing dental sealants in the past involved removing enamel in the deep fissures and grooves of a tooth and replacing it with a restorative material.^[31] Presently, it is more common to only remove decayed enamel if present. In spite of this, there are still cases where deep fissures and grooves in enamel are removed in order to prevent decay, and a sealant may or may not be placed depending on the situation. Sealants are unique in that they are preventative restorations for protection from future decay and have shown to reduce the risk of decay by 55% over 7 years.^[32] Dental sealants are a dental treatment consisting of applying a plastic material to one or more teeth, for the intended purpose of preventing dental caries (cavities) or other forms of tooth decay. ...

Aesthetics is another reason for the removal of enamel. Removing enamel is necessary when placing crowns and veneers to enhance the appearance of teeth. In both of these instances, it is important to keep in mind the orientation of enamel rods because it is possible to leave enamel unsupported by underlying dentin, leaving that portion of the prepared teeth more vulnerable to fracture.^[33] Crown A crown, or full-coverage restoration (sometimes incorrectly called a cap) is a prosthetic tooth designed by a dentist and usually created by a lab technician (or more recently, a CAD-CAM machine). ... In dentistry, a veneer is a thin layer of restorative material placed over a tooth surface, either to improve the aesthetics of a tooth, or to protect a damaged tooth surface. ...

Acid-etching techniques

Invented in 1955, acid-etching employs dental etchants and is used frequently when bonding dental restoration to teeth.^[34] This is important for long-term use of some materials, such as composites and sealants.^[12] By dissolving minerals in enamel, etchants remove the outer 10 micrometers on the enamel surface and makes a porous layer 5–50 micrometers deep.^[35] This roughens the enamel microscopically and results in a greater surface area on which to bond. Dental composites are a group of restorative material used in dentistry. ... Dental sealants are a dental treatment consisting of applying a plastic material to one or more teeth, for the intended purpose of preventing dental caries (cavities) or other forms of tooth decay. ...

The effects of acid-etching on enamel can vary. Important variables are the amount of time the etchant is applied, the type of etchant used, and the current condition of the enamel.^[35]

There are three types of patterns formed by acid-etching.^[35] Type 1 is a pattern where predominantly the enamel rods are dissolved; type 2 is a pattern where predominantly the area around the enamel rods are dissolved; and type 3 is a pattern where there is no evidence left of any enamel rods. Besides concluding that type 1 is the most favorable pattern and type 3 the least, the explanation for these different patterns is not known for certain but is most commonly attributed to different crystal orientation in the enamel.^[36]

Tooth whitening

Tooth whitening or tooth bleaching are procedures that attempt to lighten a tooth's color in either of two ways: by chemical or mechanical action.^[37] Tooth Whitener for Home Use (Brush for Application) Tooth bleaching, also known as tooth whitening, is a common procedure in general dentistry but most especially in the field of cosmetic dentistry. ...

Working chemically, a bleaching agent is used to carry out an oxidation reaction in the enamel and dentin.^[38] The agents most commonly used to intrinsically change the color of teeth are hydrogen peroxide and carbamide peroxide.^[39] A tooth whitening product with an overall low pH can put enamel at risk for decay or destruction by demineralization. Consequently, care should be taken and risk evaluated when choosing a product which is very acidic.^[40] Hydrogen peroxide (H2O2) is a very pale blue liquid which appears colorless in a dilute solution, slightly more viscous than water. ... Carbamide peroxide is an oxidising agent, consisting of hydrogen peroxide compounded with urea. ...

Tooth whiteners in toothpastes work through a mechanical action. They have mild abrasives which aid in the removal of stains on enamel. Although this can be an effective method, it does not alter the intrinsic color of teeth.^[37]

Microabrasion techniques employ both methods. An acid is used first to weaken the outer 22–27 micrometers of enamel in order to weaken it enough for the subsequent abrasive force.^[41] This allows for removal of superficial stains in the enamel. If the discoloration is deeper or in the dentin, this method of tooth whitening will not be successful.

Systemic conditions affecting enamel

There are many different types of Amelogenesis imperfecta. The hypocalcification type, which is the most common, is an autosomal dominant condition that results in enamel that is not completely mineralized.^[42] Consequently, enamel easily flakes off the teeth, which appear yellow because of the revealed dentin. The hypoplastic type is X-linked and results in normal enamel that appears in too little quantity, having the same effect as the most common type.^[42] Amelogenesis Imperfecta is an inherited condition that presents abnormal formation of the enamel or external layer of teeth. ... It has been suggested that this article or section be merged into Dominance relationship. ... Sex-linked genes are those carried on the mammalian X chromosome but not the Y chromosome. ...

Chronic bilirubin encephalopathy, which can result from erythroblastosis fetalis, is a disease which has numerous effects on an infant, but it can also cause enamel hypoplasia and green staining of enamel.^[43] Encephalopathy literally means disease of the brain. ... Erythroblastosis fetalis, also known as hemolytic disease of the newborn is a condition that develops in a fetus when antibodies produced by the mother attack the fetuss red blood cells. ... “Baby” redirects here. ...

Enamel hypoplasia is broadly defined to encompass all deviations from normal enamel in its various degrees of absence.^[44] The missing enamel could be localized, forming a small pit, or it could be completely absent.

Erythropoietic porphyria is a genetic disease resulting in the deposition of porphyrins throughout the body. These deposits also occur in enamel and leave an appearance described as red in color and fluorescent.^[45] Porphyrias are a group of inherited or acquired disorders of certain enzymes in the heme biosynthetic pathway (also called porphyrin pathway). ... Structure of porphine, the simplest porphyrin. ...

Fluorosis leads to mottled enamel and occurs from overexposure to fluoride.^[23] Picture of a mild case of fluorosis. ...

Tetracycline staining leads to brown bands on the areas of developing enamel. Children up to age 8 can develop mottled enamel from taking tetracycline. As a result, tetracycline is contraindicated in pregnant women. Tetracycline (INN) (IPA: ) is a broad-spectrum antibiotic produced by the streptomyces bacterium, indicated for use against many bacterial infections. ... This article is about human pregnancy in biological females. ...

Celiac disease, an auto-immune disorder triggered by gluten allergies, also commonly results in demineralization of the enamel. Coeliac disease (also termed non-tropical sprue, celiac disease and gluten intolerance) is an autoimmune disease characterised by chronic inflammation of the proximal portion of the small intestine caused by exposure to certain dietary gluten proteins. ...

Enamel in animals

For the most part, research has shown that formation in animals is almost identical to formation in humans. The enamel organ, including the dental papilla, and ameloblasts function similarly.^[46] The variations of enamel that are present are infrequent but sometimes important. Differences exist, certainly, in the morphology, number, and types of teeth among animals.

Teeth of a rottweiler

Dogs are less likely than humans to have tooth decay due to the high pH of dog saliva, which prevents an acidic environment from forming and the subsequent demineralization of enamel which would occur.^[47] In the event that tooth decay does occur (usually from trauma), dogs can receive dental fillings just as humans do. Similar to human teeth, the enamel of dogs is vulnerable to tetracycline staining. Consequently, this risk must be accounted for when tetracycline antibiotic therapy is administered to young dogs.^[47] Enamel hypoplasia may also occur in dogs.^[48] Image File history File links Cropped photo of a rottweiler, focusing on the teeth. ... Image File history File links Cropped photo of a rottweiler, focusing on the teeth. ... Tetracycline (INN) (IPA: ) is a broad-spectrum antibiotic produced by the streptomyces bacterium, indicated for use against many bacterial infections. ...

The mineral distribution in rodent enamel is different from that of monkeys, dogs, pigs, and humans.^[49] In horse teeth, the enamel and dentin layers are intertwined with each other, which increases the strength and decreases the wear rate of those teeth.^[50] Suborders Sciuromorpha Castorimorpha Myomorpha Anomaluromorpha Hystricomorpha Rodentia is an order of mammals also known as rodents, characterised by two continuously-growing incisors in the upper and lower jaws which must be kept short by gnawing. ... A view of the upper half of a horses mouth. ...

See also

• Dental caries
• Tooth
• Fluorite
• Ivory
• Keratin
• Elephant and Mammoth ivory
• Walrus ivory
• Perikymata
• Fluoride therapy
• Head and neck anatomy
• Amorphous calcium and phosphate

Teeth redirects here. ... Fluorite (also called fluorspar) is a mineral composed of calcium fluoride, CaF2. ... This article or section does not cite its references or sources. ... Not to be confused with kerogen or carotene. ... Elephant and mammoth tusk ivory comes from the two modified upper incisors of extant and extinct members of the same order (Proboscidea). ... Walrus tusk ivory comes from two modified upper canines. ... Perikymata (Greek plural of: perikyma) are the pits around the long microscopical prisms of tooth enamel. ... Fluoride therapy is the delivery of fluoride to the teeth topically or systemically, which is designed to prevent tooth decay (dental caries) which results in cavities. ... An MRI scan of the head. ...

Notes

References

• American Dental Association (1995) "Caries diagnosis and risk assessment: a review of preventive strategies and management", in association with Council on Access Prevention and Interprofessional Relations, Journal of the American Dental Association, 126, 1S–24S
• American Dental Association (2007) Oral Health Topics A-Z: Tooth whitening treatments, Online FAQ, accessed 7 October 2007
• American Dental Hygienists' Association (2007) "Oral Health Information", webpage, accessed 7 October 2007
• Ash, Major M., Jr. and Nelson, S.J. (2003) Dental anatomy, physiology, and occlusion, 8th ed., Philadelphia: W.B. Saunders, ISBN 0-7216-9382-2
• Blackwell, Bonnie (1996) "Why Teeth Fossilize Better Than Bone", Dinosaur mailing list, accessed 7 October 2007
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is the 280th day of the year (281st in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) was a common year starting on Monday of the Gregorian calendar in the 21st century. ... is the 280th day of the year (281st in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) was a common year starting on Monday of the Gregorian calendar in the 21st century. ... is the 280th day of the year (281st in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) was a common year starting on Monday of the Gregorian calendar in the 21st century. ... is the 280th day of the year (281st in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) was a common year starting on Monday of the Gregorian calendar in the 21st century. ... is the 280th day of the year (281st in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) was a common year starting on Monday of the Gregorian calendar in the 21st century. ... is the 280th day of the year (281st in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) was a common year starting on Monday of the Gregorian calendar in the 21st century. ... is the 280th day of the year (281st in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) was a common year starting on Monday of the Gregorian calendar in the 21st century. ... is the 280th day of the year (281st in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) was a common year starting on Monday of the Gregorian calendar in the 21st century. ... is the 281st day of the year (282nd in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) was a common year starting on Monday of the Gregorian calendar in the 21st century. ... is the 280th day of the year (281st in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) was a common year starting on Monday of the Gregorian calendar in the 21st century. ...

External links

• FAQ Category: Tooth Enamel
• Demineralization