Onlays are dental restorations for teeth that have cavities. Usually, the process to fit them takes place at least two dental visits. At the first visit, the dentist performs the onlay preparation, and at the second visit, they fit the permanent onlay restoration. Onlays also fit inside the tooth but extend onto the chewing surface of a back tooth to replace one or more cusps. In the past, onlays were made only of gold, but like inlays, more and more patients request a tooth-colored onlay. Making the onlay of ceramic/porcelain allows the restoration to be bonded to the tooth. This bonding process may actually improve the strength of the tooth and help seal the onlay to the tooth.
