Composite Resins: Synthetic resins, containing an inert filler, that are widely used in dentistry.Materials Testing: The testing of materials and devices, especially those used for PROSTHESES AND IMPLANTS; SUTURES; TISSUE ADHESIVES; etc., for hardness, strength, durability, safety, efficacy, and biocompatibility.Dental Materials: Materials used in the production of dental bases, restorations, impressions, prostheses, etc.Acrylic ResinsBisphenol A-Glycidyl Methacrylate: The reaction product of bisphenol A and glycidyl methacrylate that undergoes polymerization when exposed to ultraviolet light or mixed with a catalyst. It is used as a bond implant material and as the resin component of dental sealants and composite restorative materials.Methacrylates: Acrylic acids or acrylates which are substituted in the C-2 position with a methyl group.Dental Restoration, Permanent: A restoration designed to remain in service for not less than 20 to 30 years, usually made of gold casting, cohesive gold, or amalgam. (Jablonski, Dictionary of Dentistry, 1992)Resins, Synthetic: Polymers of high molecular weight which at some stage are capable of being molded and then harden to form useful components.Dental Polishing: Creation of a smooth and glossy surface finish on a denture or amalgam.Polymethacrylic Acids: Poly-2-methylpropenoic acids. Used in the manufacture of methacrylate resins and plastics in the form of pellets and granules, as absorbent for biological materials and as filters; also as biological membranes and as hydrogens. Synonyms: methylacrylate polymer; poly(methylacrylate); acrylic acid methyl ester polymer.Resins, Plant: Flammable, amorphous, vegetable products of secretion or disintegration, usually formed in special cavities of plants. They are generally insoluble in water and soluble in alcohol, carbon tetrachloride, ether, or volatile oils. They are fusible and have a conchoidal fracture. They are the oxidation or polymerization products of the terpenes, and are mixtures of aromatic acids and esters. Most are soft and sticky, but harden after exposure to cold. (From Grant & Hackh's Chemical Dictionary, 5th ed & Dorland, 28th ed)Hardness: The mechanical property of material that determines its resistance to force. HARDNESS TESTS measure this property.Dental Stress Analysis: The description and measurement of the various factors that produce physical stress upon dental restorations, prostheses, or appliances, materials associated with them, or the natural oral structures.Dental Bonding: An adhesion procedure for orthodontic attachments, such as plastic DENTAL CROWNS. This process usually includes the application of an adhesive material (DENTAL CEMENTS) and letting it harden in-place by light or chemical curing.Light-Curing of Dental Adhesives: The hardening or polymerization of bonding agents (DENTAL CEMENTS) via exposure to light.Curing Lights, Dental: Light sources used to activate polymerization of light-cured DENTAL CEMENTS and DENTAL RESINS. Degree of cure and bond strength depends on exposure time, wavelength, and intensity of the curing light.Surface Properties: Characteristics or attributes of the outer boundaries of objects, including molecules.Polyurethanes: A group of thermoplastic or thermosetting polymers containing polyisocyanate. They are used as ELASTOMERS, as coatings, as fibers and as foams.Dental Restoration Wear: Occlusal wear of the surfaces of restorations and surface wear of dentures.Resin Cements: Dental cements composed either of polymethyl methacrylate or dimethacrylate, produced by mixing an acrylic monomer liquid with acrylic polymers and mineral fillers. The cement is insoluble in water and is thus resistant to fluids in the mouth, but is also irritating to the dental pulp. It is used chiefly as a luting agent for fabricated and temporary restorations. (Jablonski's Dictionary of Dentistry, 1992, p159)Nanocomposites: Nanometer-scale composite structures composed of organic molecules intimately incorporated with inorganic molecules. (Glossary of Biotechnology and Nanobiotechology Terms, 4th ed)Silanes: Compounds similar to hydrocarbons in which a tetravalent silicon atom replaces the carbon atom. They are very reactive, ignite in air, and form useful derivatives.Dental Cements: Substances used to bond COMPOSITE RESINS to DENTAL ENAMEL and DENTIN. These bonding or luting agents are used in restorative dentistry, ROOT CANAL THERAPY; PROSTHODONTICS; and ORTHODONTICS.Crowns: A prosthetic restoration that reproduces the entire surface anatomy of the visible natural crown of a tooth. It may be partial (covering three or more surfaces of a tooth) or complete (covering all surfaces). It is made of gold or other metal, porcelain, or resin.Dental Restoration Failure: Inability or inadequacy of a dental restoration or prosthesis to perform as expected.Zirconium: Zirconium. A rather rare metallic element, atomic number 40, atomic weight 91.22, symbol Zr. (From Dorland, 28th ed)Pliability: The quality or state of being able to be bent or creased repeatedly. (From Webster, 3d ed)Dental Cavity Preparation: An operation in which carious material is removed from teeth and biomechanically correct forms are established in the teeth to receive and retain restorations. A constant requirement is provision for prevention of failure of the restoration through recurrence of decay or inadequate resistance to applied stresses. (Boucher's Clinical Dental Terminology, 4th ed, p239-40)Compomers: Composite materials composed of an ion-leachable glass embedded in a polymeric matrix. They differ from GLASS IONOMER CEMENTS in that partially silanized glass particles are used to provide a direct bond to the resin matrix and the matrix is primarily formed by a light-activated, radical polymerization reaction.Polymerization: Chemical reaction in which monomeric components are combined to form POLYMERS (e.g., POLYMETHYLMETHACRYLATE).Self-Curing of Dental Resins: The hardening or polymerization of bonding agents (DENTAL CEMENTS) via chemical reactions, usually involving two components. This type of dental bonding uses a self-cure or dual-cure system.Tensile Strength: The maximum stress a material subjected to a stretching load can withstand without tearing. (McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed, p2001)Dental Enamel: A hard thin translucent layer of calcified substance which envelops and protects the dentin of the crown of the tooth. It is the hardest substance in the body and is almost entirely composed of calcium salts. Under the microscope, it is composed of thin rods (enamel prisms) held together by cementing substance, and surrounded by an enamel sheath. (From Jablonski, Dictionary of Dentistry, 1992, p286)Dentin-Bonding Agents: Cements that act through infiltration and polymerization within the dentinal matrix and are used for dental restoration. They can be adhesive resins themselves, adhesion-promoting monomers, or polymerization initiators that act in concert with other agents to form a dentin-bonding system.Dental Marginal Adaptation: The degree of approximation or fit of filling material or dental prosthetic to the tooth surface. A close marginal adaptation and seal at the interface is important for successful dental restorations.Acid Etching, Dental: Preparation of TOOTH surfaces and DENTAL MATERIALS with etching agents, usually phosphoric acid, to roughen the surface to increase adhesion or osteointegration.Dentin: The hard portion of the tooth surrounding the pulp, covered by enamel on the crown and cementum on the root, which is harder and denser than bone but softer than enamel, and is thus readily abraded when left unprotected. (From Jablonski, Dictionary of Dentistry, 1992)Glass Ionomer Cements: A polymer obtained by reacting polyacrylic acid with a special anion-leachable glass (alumino-silicate). The resulting cement is more durable and tougher than others in that the materials comprising the polymer backbone do not leach out.Post and Core Technique: Use of a metal casting, usually with a post in the pulp or root canal, designed to support and retain an artificial crown.Prosthesis Coloring: Coloring, shading, or tinting of prosthetic components, devices, and materials.Saliva, Artificial: A solution used for irrigating the mouth in xerostomia and as a substitute for saliva.Glass: Hard, amorphous, brittle, inorganic, usually transparent, polymerous silicate of basic oxides, usually potassium or sodium. It is used in the form of hard sheets, vessels, tubing, fibers, ceramics, beads, etc.Shear Strength: The internal resistance of a material to moving some parts of it parallel to a fixed plane, in contrast to stretching (TENSILE STRENGTH) or compression (COMPRESSIVE STRENGTH). Ionic crystals are brittle because, when subjected to shear, ions of the same charge are brought next to each other, which causes repulsion.Siloxanes: Silicon polymers that contain alternate silicon and oxygen atoms in linear or cyclic molecular structures.Phosphoric Acids: Inorganic derivatives of phosphoric acid (H3PO4). Note that organic derivatives of phosphoric acids are listed under ORGANOPHOSPHATES.Ion Exchange Resins: High molecular weight, insoluble polymers which contain functional groups that are capable of undergoing exchange reactions (ION EXCHANGE) with either cations or anions.Inlays: Restorations of metal, porcelain, or plastic made to fit a cavity preparation, then cemented into the tooth. Onlays are restorations which fit into cavity preparations and overlay the occlusal surface of a tooth or teeth. Onlays are retained by frictional or mechanical factors.Silorane Resins: Polymeric resins containing a combination of SILOXANES and OXIRANES.Color: The visually perceived property of objects created by absorption or reflection of specific wavelengths of light.Dental Restoration Repair: The process of repairing broken or worn parts of a PERMANENT DENTAL RESTORATION.Tooth Fractures: Break or rupture of a tooth or tooth root.Silicon Dioxide: Transparent, tasteless crystals found in nature as agate, amethyst, chalcedony, cristobalite, flint, sand, QUARTZ, and tridymite. The compound is insoluble in water or acids except hydrofluoric acid.Dental Etching: Preparation of TOOTH surfaces, and of materials bonded to teeth or DENTAL IMPLANTS, with agents and methods which roughen the surface to facilitate adhesion. Agents include phosphoric or other acids (ACID ETCHING, DENTAL) and methods include LASERS.Dental Cavity Lining: An inner coating, as of varnish or other protective substance, to cover the dental cavity wall. It is usually a resinous film-forming agent dissolved in a volatile solvent, or a suspension of calcium hydroxide in a solution of a synthetic resin. The lining seals the dentinal tubules and protects the pulp before a restoration is inserted. (Jablonski, Illustrated Dictionary of Dentistry, 1982)Gold Alloys: Alloys that contain a high percentage of gold. They are used in restorative or prosthetic dentistry.Microscopy, Electron, Scanning: Microscopy in which the object is examined directly by an electron beam scanning the specimen point-by-point. The image is constructed by detecting the products of specimen interactions that are projected above the plane of the sample, such as backscattered electrons. Although SCANNING TRANSMISSION ELECTRON MICROSCOPY also scans the specimen point by point with the electron beam, the image is constructed by detecting the electrons, or their interaction products that are transmitted through the sample plane, so that is a form of TRANSMISSION ELECTRON MICROSCOPY.Dental Prosthesis Design: The plan and delineation of dental prostheses in general or a specific dental prosthesis. It does not include DENTURE DESIGN. The framework usually consists of metal.Epoxy Resins: Polymeric resins derived from OXIRANES and characterized by strength and thermosetting properties. Epoxy resins are often used as dental materials.Tooth, Nonvital: A tooth from which the dental pulp has been removed or is necrotic. (Boucher, Clinical Dental Terminology, 4th ed)Aluminum Oxide: An oxide of aluminum, occurring in nature as various minerals such as bauxite, corundum, etc. It is used as an adsorbent, desiccating agent, and catalyst, and in the manufacture of dental cements and refractories.Carbon Compounds, Inorganic: Inorganic compounds that contain carbon as an integral part of the molecule but are not derived from hydrocarbons.Hardness Tests: A test to determine the relative hardness of a metal, mineral, or other material according to one of several scales, such as Brinell, Mohs, Rockwell, Vickers, or Shore. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Physicochemical Processes: Physical reactions involved in the formation of or changes in the structure of atoms and molecules and their interactions.Dental Porcelain: A type of porcelain used in dental restorations, either jacket crowns or inlays, artificial teeth, or metal-ceramic crowns. It is essentially a mixture of particles of feldspar and quartz, the feldspar melting first and providing a glass matrix for the quartz. Dental porcelain is produced by mixing ceramic powder (a mixture of quartz, kaolin, pigments, opacifiers, a suitable flux, and other substances) with distilled water. (From Jablonski's Dictionary of Dentistry, 1992)Tooth, Artificial: A fabricated tooth substituting for a natural tooth in a prosthesis. It is usually made of porcelain or plastic.Tooth Bleaching Agents: Chemicals that are used to oxidize pigments in TEETH and thus effect whitening.Dental Leakage: The seepage of fluids, debris, and micro-organisms between the walls of a prepared dental cavity and the restoration.Ceramics: Products made by baking or firing nonmetallic minerals (clay and similar materials). In making dental restorations or parts of restorations the material is fused porcelain. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed & Boucher's Clinical Dental Terminology, 4th ed)Toothbrushing: The act of cleaning teeth with a brush to remove plaque and prevent tooth decay. (From Webster, 3d ed)Bicuspid: One of the eight permanent teeth, two on either side in each jaw, between the canines (CUSPID) and the molars (MOLAR), serving for grinding and crushing food. The upper have two cusps (bicuspid) but the lower have one to three. (Jablonski, Dictionary of Dentistry, 1992, p822)Immersion: The placing of a body or a part thereof into a liquid.Stress, Mechanical: A purely physical condition which exists within any material because of strain or deformation by external forces or by non-uniform thermal expansion; expressed quantitatively in units of force per unit area.Dental Restoration, Temporary: A prosthesis or restoration placed for a limited period, from several days to several months, which is designed to seal the tooth and maintain its position until a permanent restoration (DENTAL RESTORATION, PERMANENT) will replace it. (From Jablonski, Dictionary of Dentistry, 1992)Photoinitiators, Dental: Chemical compound used to initiate polymerization of dental resins by the use of DENTAL CURING LIGHTS. It absorbs UV light and undergoes decomposition into free radicals that initiate polymerization process of the resins in the mix. Each photoinitiator has optimum emission spectrum and intensity for proper curing of dental materials.Dental Veneers: The use of a layer of tooth-colored material, usually porcelain or acrylic resin, applied to the surface of natural teeth, crowns, or pontics by fusion, cementation, or mechanical retention.Aluminum Silicates: Any of the numerous types of clay which contain varying proportions of Al2O3 and SiO2. They are made synthetically by heating aluminum fluoride at 1000-2000 degrees C with silica and water vapor. (From Hawley's Condensed Chemical Dictionary, 11th ed)Dental Alloys: A mixture of metallic elements or compounds with other metallic or metalloid elements in varying proportions for use in restorative or prosthetic dentistry.Organically Modified Ceramics: Organic-inorganic hybrid polymers developed primarily for DENTAL RESTORATION. They typically contain a defined mixture of ORGANOSILICON COMPOUNDS; CERAMICS; and organic POLYMERS.Tooth Abrasion: The pathologic wearing away of the tooth substance by brushing, bruxism, clenching, and other mechanical causes. It is differentiated from TOOTH ATTRITION in that this type of wearing away is the result of tooth-to-tooth contact, as in mastication, occurring only on the occlusal, incisal, and proximal surfaces. It differs also from TOOTH EROSION, the progressive loss of the hard substance of a tooth by chemical processes not involving bacterial action. (From Jablonski, Dictionary of Dentistry, 1992, p2)Barium Compounds: Inorganic compounds that contain barium as an integral part of the molecule.Analysis of Variance: A statistical technique that isolates and assesses the contributions of categorical independent variables to variation in the mean of a continuous dependent variable.Electron Probe Microanalysis: Identification and measurement of ELEMENTS and their location based on the fact that X-RAYS emitted by an element excited by an electron beam have a wavelength characteristic of that element and an intensity related to its concentration. It is performed with an electron microscope fitted with an x-ray spectrometer, in scanning or transmission mode.Tooth Bleaching: The use of a chemical oxidizing agent to whiten TEETH. In some procedures the oxidation process is activated by the use of heat or light.Dental Amalgam: An alloy used in restorative dentistry that contains mercury, silver, tin, copper, and possibly zinc.Stainless Steel: Stainless steel. A steel containing Ni, Cr, or both. It does not tarnish on exposure and is used in corrosive environments. (Grant & Hack's Chemical Dictionary, 5th ed)Halogens: A family of nonmetallic, generally electronegative, elements that form group 17 (formerly group VIIa) of the periodic table.Diamond: Diamond. A crystalline form of carbon that occurs as hard, colorless or tinted isomeric crystals. It is used as a precious stone, for cutting glass, and as bearings for delicate mechanisms. (From Grant & Hackh's Chemical Dictionary, 5th ed)Water: A clear, odorless, tasteless liquid that is essential for most animal and plant life and is an excellent solvent for many substances. The chemical formula is hydrogen oxide (H2O). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Adhesiveness: A property of the surface of an object that makes it stick to another surface.Dental Abutments: Natural teeth or teeth roots used as anchorage for a fixed or removable denture or other prosthesis (such as an implant) serving the same purpose.Denture Repair: The process of reuniting or replacing broken or worn parts of a denture.Silicates: The generic term for salts derived from silica or the silicic acids. They contain silicon, oxygen, and one or more metals, and may contain hydrogen. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th Ed)Phase Transition: A change of a substance from one form or state to another.Adhesives: Substances that cause the adherence of two surfaces. They include glues (properly collagen-derived adhesives), mucilages, sticky pastes, gums, resins, or latex.Orthodontic Brackets: Small metal or ceramic attachments used to fasten an arch wire. These attachments are soldered or welded to an orthodontic band or cemented directly onto the teeth. Bowles brackets, edgewise brackets, multiphase brackets, ribbon arch brackets, twin-wire brackets, and universal brackets are all types of orthodontic brackets.Molar: The most posterior teeth on either side of the jaw, totaling eight in the deciduous dentition (2 on each side, upper and lower), and usually 12 in the permanent dentition (three on each side, upper and lower). They are grinding teeth, having large crowns and broad chewing surfaces. (Jablonski, Dictionary of Dentistry, 1992, p821)Tooth Preparation: Procedures carried out with regard to the teeth or tooth structures preparatory to specified dental therapeutic and surgical measures.Silicon Compounds: Inorganic compounds that contain silicon as an integral part of the molecule.Polycarboxylate Cement: Water-soluble low-molecular-weight polymers of acrylic or methacrylic acid that form solid, insoluble products when mixed with specially prepared ZnO powder. The resulting cement adheres to dental enamel and is also used as a luting agent.Tooth Root: The part of a tooth from the neck to the apex, embedded in the alveolar process and covered with cementum. A root may be single or divided into several branches, usually identified by their relative position, e.g., lingual root or buccal root. Single-rooted teeth include mandibular first and second premolars and the maxillary second premolar teeth. The maxillary first premolar has two roots in most cases. Maxillary molars have three roots. (Jablonski, Dictionary of Dentistry, 1992, p690)Quartz: Quartz (SiO2). A glassy or crystalline form of silicon dioxide. Many colored varieties are semiprecious stones. (From Grant & Hackh's Chemical Dictionary, 5th ed)Tooth Preparation, Prosthodontic: The selected form given to a natural tooth when it is reduced by instrumentation to receive a prosthesis (e.g., artificial crown or a retainer for a fixed or removable prosthesis). The selection of the form is guided by clinical circumstances and physical properties of the materials that make up the prosthesis. (Boucher's Clinical Dental Terminology, 4th ed, p239)Methylmethacrylates: The methyl esters of methacrylic acid that polymerize easily and are used as tissue cements, dental materials, and absorbent for biological substances.Compressive Strength: The maximum compression a material can withstand without failure. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed, p427)Anion Exchange Resins: High-molecular-weight insoluble polymers that contain functional cationic groups capable of undergoing exchange reactions with anions.Polymethyl Methacrylate: Polymerized methyl methacrylate monomers which are used as sheets, moulding, extrusion powders, surface coating resins, emulsion polymers, fibers, inks, and films (From International Labor Organization, 1983). This material is also used in tooth implants, bone cements, and hard corneal contact lenses.Wettability: The quality or state of being wettable or the degree to which something can be wet. This is also the ability of any solid surface to be wetted when in contact with a liquid whose surface tension is reduced so that the liquid spreads over the surface of the solid.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Bite Force: The force applied by the masticatory muscles in dental occlusion.Hydrofluoric Acid: Hydrofluoric acid. A solution of hydrogen fluoride in water. It is a colorless fuming liquid which can cause painful burns.Denture, Partial: A denture replacing one or more (but not all) natural teeth. It is supported and retained by underlying tissue and some or all of the remaining teeth.Thermogravimetry: Technique whereby the weight of a sample can be followed over a period of time while its temperature is being changed (usually increased at a constant rate).Colorimetry: Any technique by which an unknown color is evaluated in terms of standard colors. The technique may be visual, photoelectric, or indirect by means of spectrophotometry. It is used in chemistry and physics. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Cariostatic Agents: Substances that inhibit or arrest DENTAL CARIES formation. (Boucher's Clinical Dental Terminology, 4th ed)Polymers: Compounds formed by the joining of smaller, usually repeating, units linked by covalent bonds. These compounds often form large macromolecules (e.g., BIOPOLYMERS; PLASTICS).Elastic Modulus: Numerical expression indicating the measure of stiffness in a material. It is defined by the ratio of stress in a unit area of substance to the resulting deformation (strain). This allows the behavior of a material under load (such as bone) to be calculated.Cation Exchange Resins: High molecular weight insoluble polymers which contain functional anionic groups that are capable of undergoing exchange reactions with cations.Polyethylene Glycols: Polymers of ETHYLENE OXIDE and water, and their ethers. They vary in consistency from liquid to solid depending on the molecular weight indicated by a number following the name. They are used as SURFACTANTS, dispersing agents, solvents, ointment and suppository bases, vehicles, and tablet excipients. Some specific groups are NONOXYNOLS, OCTOXYNOLS, and POLOXAMERS.Light: That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.Tooth Cervix: The constricted part of the tooth at the junction of the crown and root or roots. It is often referred to as the cementoenamel junction (CEJ), the line at which the cementum covering the root of a tooth and the enamel of the tooth meet. (Jablonski, Dictionary of Dentistry, 1992, p530, p433)Dental Equipment: The nonexpendable items used by the dentist or dental staff in the performance of professional duties. (From Boucher's Clinical Dental Terminology, 4th ed, p106)Denture Bases: The part of a denture that overlies the soft tissue and supports the supplied teeth and is supported in turn by abutment teeth or the residual alveolar ridge. It is usually made of resins or metal or their combination.Tooth Wear: Loss of the tooth substance by chemical or mechanical processesBrompheniramine: Histamine H1 antagonist used in treatment of allergies, rhinitis, and urticaria.Statistics, Nonparametric: A class of statistical methods applicable to a large set of probability distributions used to test for correlation, location, independence, etc. In most nonparametric statistical tests, the original scores or observations are replaced by another variable containing less information. An important class of nonparametric tests employs the ordinal properties of the data. Another class of tests uses information about whether an observation is above or below some fixed value such as the median, and a third class is based on the frequency of the occurrence of runs in the data. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed, p1284; Corsini, Concise Encyclopedia of Psychology, 1987, p764-5)Silver: Silver. An element with the atomic symbol Ag, atomic number 47, and atomic weight 107.87. It is a soft metal that is used medically in surgical instruments, dental prostheses, and alloys. Long-continued use of silver salts can lead to a form of poisoning known as ARGYRIA.Air Abrasion, Dental: A technique using a pneumatic, high-pressure stream of aluminum oxide to remove DENTAL ENAMEL; DENTIN; and restorative materials from teeth. In contrast to using DENTAL HIGH-SPEED EQUIPMENT, this method usually requires no dental anesthesia (ANESTHESIA, DENTAL) and reduces risks of tooth chipping and microfracturing. It is used primarily for routine DENTAL CAVITY PREPARATION.Drug Storage: The process of keeping pharmaceutical products in an appropriate location.Particle Size: Relating to the size of solids.Semiconductors: Materials that have a limited and usually variable electrical conductivity. They are particularly useful for the production of solid-state electronic devices.Photochemical Processes: Chemical reactions effected by light.Magnesium Oxide: Magnesium oxide (MgO). An inorganic compound that occurs in nature as the mineral periclase. In aqueous media combines quickly with water to form magnesium hydroxide. It is used as an antacid and mild laxative and has many nonmedicinal uses.Incisor: Any of the eight frontal teeth (four maxillary and four mandibular) having a sharp incisal edge for cutting food and a single root, which occurs in man both as a deciduous and a permanent tooth. (Jablonski, Dictionary of Dentistry, 1992, p820)Elasticity: Resistance and recovery from distortion of shape.Methylmethacrylate: The methyl ester of methacrylic acid. It polymerizes easily to form POLYMETHYL METHACRYLATE. It is used as a bone cement.Tooth, Deciduous: The teeth of the first dentition, which are shed and replaced by the permanent teeth.Pseudoephedrine: A phenethylamine that is an isomer of EPHEDRINE which has less central nervous system effects and usage is mainly for respiratory tract decongestion.Astringents: Agents, usually topical, that cause the contraction of tissues for the control of bleeding or secretions.Dentistry, Operative: That phase of clinical dentistry concerned with the restoration of parts of existing teeth that are defective through disease, trauma, or abnormal development, to the state of normal function, health, and esthetics, including preventive, diagnostic, biological, mechanical, and therapeutic techniques, as well as material and instrument science and application. (Jablonski's Dictionary of Dentistry, 2d ed, p237)Dental Prosthesis Repair: The process of reuniting or replacing a broken or worn dental prosthesis or its part.Metal Ceramic Alloys: The fusion of ceramics (porcelain) to an alloy of two or more metals for use in restorative and prosthodontic dentistry. Examples of metal alloys employed include cobalt-chromium, gold-palladium, gold-platinum-palladium, and nickel-based alloys.Temperature: The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.Esthetics, Dental: Skills, techniques, standards, and principles used to improve the art and symmetry of the teeth and face to improve the appearance as well as the function of the teeth, mouth, and face. (From Boucher's Clinical Dental Terminology, 4th ed, p108)Spectrometry, X-Ray Emission: The spectrometric analysis of fluorescent X-RAYS, i.e. X-rays emitted after bombarding matter with high energy particles such as PROTONS; ELECTRONS; or higher energy X-rays. Identification of ELEMENTS by this technique is based on the specific type of X-rays that are emitted which are characteristic of the specific elements in the material being analyzed. The characteristic X-rays are distinguished and/or quantified by either wavelength dispersive or energy dispersive methods.Zinc Oxide: A mild astringent and topical protectant with some antiseptic action. It is also used in bandages, pastes, ointments, dental cements, and as a sunblock.Dental High-Speed Equipment: Tools used in dentistry that operate at high rotation speeds.Absorption: The physical or physiological processes by which substances, tissue, cells, etc. take up or take in other substances or energy.Tooth Demineralization: A tooth's loss of minerals, such as calcium in hydroxyapatite from the tooth matrix, caused by acidic exposure. An example of the occurrence of demineralization is in the formation of dental caries.Titanium: A dark-gray, metallic element of widespread distribution but occurring in small amounts; atomic number, 22; atomic weight, 47.90; symbol, Ti; specific gravity, 4.5; used for fixation of fractures. (Dorland, 28th ed)Fluorides: Inorganic salts of hydrofluoric acid, HF, in which the fluorine atom is in the -1 oxidation state. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed) Sodium and stannous salts are commonly used in dentifrices.Optical Phenomena: LIGHT, it's processes and properties, and the characteristics of materials interacting with it.Dental Caries: Localized destruction of the tooth surface initiated by decalcification of the enamel followed by enzymatic lysis of organic structures and leading to cavity formation. If left unchecked, the cavity may penetrate the enamel and dentin and reach the pulp.Cuspid: The third tooth to the left and to the right of the midline of either jaw, situated between the second INCISOR and the premolar teeth (BICUSPID). (Jablonski, Dictionary of Dentistry, 1992, p817)Dental Pulp Capping: Application of a protective agent to an exposed pulp (direct capping) or the remaining thin layer of dentin over a nearly exposed pulp (indirect capping) in order to allow the pulp to recover and maintain its normal vitality and function.Coloring Agents: Chemicals and substances that impart color including soluble dyes and insoluble pigments. They are used in INKS; PAINTS; and as INDICATORS AND REAGENTS.Mouthwashes: Solutions for rinsing the mouth, possessing cleansing, germicidal, or palliative properties. (From Boucher's Clinical Dental Terminology, 4th ed)Potassium Compounds: Inorganic compounds that contain potassium as an integral part of the molecule.Photoelectron Spectroscopy: The study of the energy of electrons ejected from matter by the photoelectric effect, i.e., as a direct result of absorption of energy from electromagnetic radiation. As the energies of the electrons are characteristic of a specific element, the measurement of the energy of these electrons is a technique used to determine the chemical composition of surfaces.Erbium: Erbium. An element of the rare earth family of metals. It has the atomic symbol Er, atomic number 68, and atomic weight 167.26.Food Coloring Agents: Natural or synthetic dyes used as coloring agents in processed foods.Tooth Crown: The upper part of the tooth, which joins the lower part of the tooth (TOOTH ROOT) at the cervix (TOOTH CERVIX) at a line called the cementoenamel junction. The entire surface of the crown is covered with enamel which is thicker at the extremity and becomes progressively thinner toward the cervix. (From Jablonski, Dictionary of Dentistry, 1992, p216)Cementation: The joining of objects by means of a cement (e.g., in fracture fixation, such as in hip arthroplasty for joining of the acetabular component to the femoral component). In dentistry, it is used for the process of attaching parts of a tooth or restorative material to a natural tooth or for the attaching of orthodontic bands to teeth by means of an adhesive.Finite Element Analysis: A computer based method of simulating or analyzing the behavior of structures or components.Spectroscopy, Fourier Transform Infrared: A spectroscopic technique in which a range of wavelengths is presented simultaneously with an interferometer and the spectrum is mathematically derived from the pattern thus obtained.Coffee: A beverage made from ground COFFEA beans (SEEDS) infused in hot water. It generally contains CAFFEINE and THEOPHYLLINE unless it is decaffeinated.Streptococcus oralis: A species of gram-positive, coccoid bacteria that is numerous in the mouth and throat. It is a common cause of endocarditis and is also implicated in dental plaque formation.Space MaintenanceCalcium Compounds: Inorganic compounds that contain calcium as an integral part of the molecule.Rubber: A high-molecular-weight polymeric elastomer derived from the milk juice (LATEX) of HEVEA brasiliensis and other trees and plants. It is a substance that can be stretched at room temperature to at least twice its original length and after releasing the stress, retract rapidly, and recover its original dimensions fully.Viscosity: The resistance that a gaseous or liquid system offers to flow when it is subjected to shear stress. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Palladium: A chemical element having an atomic weight of 106.4, atomic number of 46, and the symbol Pd. It is a white, ductile metal resembling platinum, and following it in abundance and importance of applications. It is used in dentistry in the form of gold, silver, and copper alloys.Streptococcus sobrinus: A species of gram-positive, coccoid bacteria isolated from the human tooth surface. Strains have been shown to be cariogenic in experimental animals and may be associated with human dental caries.Aluminum Compounds: Inorganic compounds that contain aluminum as an integral part of the molecule.Random Allocation: A process involving chance used in therapeutic trials or other research endeavor for allocating experimental subjects, human or animal, between treatment and control groups, or among treatment groups. It may also apply to experiments on inanimate objects.Root Canal Preparation: Preparatory activities in ROOT CANAL THERAPY by partial or complete extirpation of diseased pulp, cleaning and sterilization of the empty canal, enlarging and shaping the canal to receive the sealing material. The cavity may be prepared by mechanical, sonic, chemical, or other means. (From Dorland, 28th ed, p1700)Peroxides: A group of compounds that contain a bivalent O-O group, i.e., the oxygen atoms are univalent. They can either be inorganic or organic in nature. Such compounds release atomic (nascent) oxygen readily. Thus they are strong oxidizing agents and fire hazards when in contact with combustible materials, especially under high-temperature conditions. The chief industrial uses of peroxides are as oxidizing agents, bleaching agents, and initiators of polymerization. (From Hawley's Condensed Chemical Dictionary, 11th ed)Dental Pulp: A richly vascularized and innervated connective tissue of mesodermal origin, contained in the central cavity of a tooth and delimited by the dentin, and having formative, nutritive, sensory, and protective functions. (Jablonski, Dictionary of Dentistry, 1992)Forensic Dentistry: The application of dental knowledge to questions of law.Dental Occlusion, Traumatic: An occlusion resulting in overstrain and injury to teeth, periodontal tissue, or other oral structures.Boron Compounds: Inorganic or organic compounds that contain boron as an integral part of the molecule.Denture Design: The plan, delineation, and location of actual structural elements of dentures. The design can relate to retainers, stress-breakers, occlusal rests, flanges, framework, lingual or palatal bars, reciprocal arms, etc.Air Pressure: The force per unit area that the air exerts on any surface in contact with it. Primarily used for articles pertaining to air pressure within a closed environment.Friction: Surface resistance to the relative motion of one body against the rubbing, sliding, rolling, or flowing of another with which it is in contact.Cattle: Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.Hot Temperature: Presence of warmth or heat or a temperature notably higher than an accustomed norm.Porosity: Condition of having pores or open spaces. This often refers to bones, bone implants, or bone cements, but can refer to the porous state of any solid substance.Silicon: A trace element that constitutes about 27.6% of the earth's crust in the form of SILICON DIOXIDE. It does not occur free in nature. Silicon has the atomic symbol Si, atomic number 14, and atomic weight [28.084; 28.086].Calcium Phosphates: Calcium salts of phosphoric acid. These compounds are frequently used as calcium supplements.Pit and Fissure Sealants: Agents used to occlude dental enamel pits and fissures in the prevention of dental caries.Glutaral: One of the protein CROSS-LINKING REAGENTS that is used as a disinfectant for sterilization of heat-sensitive equipment and as a laboratory reagent, especially as a fixative.Methylcellulose: Methylester of cellulose. Methylcellulose is used as an emulsifying and suspending agent in cosmetics, pharmaceutics and the chemical industry. It is used therapeutically as a bulk laxative.Terpenes: A class of compounds composed of repeating 5-carbon units of HEMITERPENES.Nanoparticles: Nanometer-sized particles that are nanoscale in three dimensions. They include nanocrystaline materials; NANOCAPSULES; METAL NANOPARTICLES; DENDRIMERS, and QUANTUM DOTS. The uses of nanoparticles include DRUG DELIVERY SYSTEMS and cancer targeting and imaging.Benzoyl Peroxide: A peroxide derivative that has been used topically for BURNS and as a dermatologic agent in the treatment of ACNE and POISON IVY DERMATITIS. It is used also as a bleach in the food industry.Powders: Substances made up of an aggregation of small particles, as that obtained by grinding or trituration of a solid drug. In pharmacy it is a form in which substances are administered. (From Dorland, 28th ed)Biocompatible Materials: Synthetic or natural materials, other than DRUGS, that are used to replace or repair any body TISSUES or bodily function.