Inlays and onlays are dental restorations used to repair rear teeth that have a mild to moderate amount of decay. They can also be used to restore teeth that are cracked or fractured if the damage is not severe enough to require a dental crown. Dental inlays are used to treat teeth that have decay or damage within the top surface. Onlays are used to treat decay that extends to one or more of the cusps. Onlays protect teeth similar to crowns but conserve more natural, healthy tooth structure. Onlays are sometimes called partial or conservative crowns.

Inlays and onlays can be made from gold, resin, or porcelain. They are stronger than composite fillings, and more conservative than crowns since less natural tooth is required to be removed during the treatment. Since the margins are invisible, they do not need to be placed below the gum line, which is healthier and easier on the gums. They are bonded to the teeth to create a tight fit and restore the tooth strength. Porcelain inlays and onlays wear better than composite fillings, and are usually less expensive than crowns. And because they can be created from tooth-colored materials, inlays and onlays are often used to replace metal fillings for patients who desire a more natural looking smile.