Dental Restoration Repair: The process of repairing broken or worn parts of a PERMANENT DENTAL RESTORATION.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)Dental Amalgam: An alloy used in restorative dentistry that contains mercury, silver, tin, copper, and possibly zinc.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, 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)Dental Materials: Materials used in the production of dental bases, restorations, impressions, prostheses, etc.Dental Restoration Wear: Occlusal wear of the surfaces of restorations and surface wear of dentures.Composite Resins: Synthetic resins, containing an inert filler, that are widely used in dentistry.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)Dental Care: The total of dental diagnostic, preventive, and restorative services provided to meet the needs of a patient (from Illustrated Dictionary of Dentistry, 1982).Methacrylates: Acrylic acids or acrylates which are substituted in the C-2 position with a methyl group.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 Restoration Failure: Inability or inadequacy of a dental restoration or prosthesis to perform as expected.Education, Dental: Use for articles concerning dental education in general.Schools, Dental: Educational institutions for individuals specializing in the field of dentistry.