Traditionally, inlays were used instead of fillings to replace a small amount of tooth structure loss due to dental decay. Like fillings, inlays fit inside the tooth.
Today, inlays are still being used as dental fillings, but the inlays can be made of a tooth-colored material such as ceramic/porcelain or special dental composite depending on what the patient wants. Defective or unsightly “fillings” can be replaced by tooth-colored inlays and bonded to the tooth in about 30mins to 1 hour. This bonding process may actually improve the strength of the tooth and help seal the inlay to the tooth.
Like inlays, 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 and look natural. This bonding process may actually improve the strength of the tooth and help seal the onlay to the tooth to prevent further decay.