Restoration of the tooth structure after decay and other damage can also be done with the use of inlays and onlays. Inlays and onlays are restorations made of porcelain, gold or composite resin material and are that are typically used to replace old fillings. Inlays and onlays are different from regular fillings because an impression of the tooth needs to be taken and the inlay or onlay is made from the mold of the tooth to fit exactly onto the tooth. An inlay restoration is similar to a regular filling in that it fits inside the top edges of the tooth. An outlay is usually more extensive and replaces the entire biting surface of the tooth.