In certain cases inlays and onlays are recommended as alternative restorations to amalgam or tooth colored fillings. Known as indirect fillings, since they are fabricated outside of the mouth, inlays or onlays can be made from either gold, porcelain or resin materials. The material selected depends upon the exact requirements of the individual case. Inlays/onlays are individually fabricated restorations that are designed to precisely fit the excavated and prepared area of a tooth that has been damaged by decay or other injury. While an inlay is used to restore the central portion of a back tooth, an onlay is a larger restoration that extends out over one or more cusps of the tooth. In certain cases an onlay can cover and support enough tooth structure to avert the need for a full coverage dental crown. Once the fit of the custom made inlay/onlay is checked, it is permanently cemented or bonded to the underlying prepared tooth structure.