A dental restoration is a material that has been placed in a prepared tooth to restore function and morphology when tooth structure has been lost due to decay or fracture (generally because of extensive caries which weakens the cusps or external trauma), or to improve the esthetics of the tooth. Dental restorations may be fabricated out of a variety of materials, and come in two broad categories: direct and indirect. Direct restorations are created inside the mouth, while indirect restorations are created outside of the mouth and require preparation in a laboratory.
While it is being prepared, a provisory restoration must be placed in the cavity, in order to maintain the occlusal space and the contact points, in addition to promoting and keeping the periodontal and pulpal tissues free of harm.
Common direct restorations include 'silver fillings' or dental amalgams, and 'tooth-colored fillings' or direct composite resin restorations. Common indirect restorations include inlays, onlays, crowns and veneers.