An inlay is an indirect filling material fabricated by a dental lab, consisting of a solid substance such as gold or porcelain fitted to a cavity in a tooth and cemented into place. An onlay is the same as an inlay, except that it extends to replace a bigger portion of the tooth. Inlays and Onlays are more often times needed when the decay or fracture is extensive and a basic filling material would compromise the structural integrity of the restored tooth leading to more damage. They are able not only to restore damaged dental tissue and protect the tooth, but to add strength to the tooth structure as well.
