Inlays & Onlays
When a tooth is too damaged to support a tooth filling but not damaged enough for a dental crown, you end up somewhere in the middle. Capping a damaged tooth unnecessarily with a dental crown removes more tooth structure than needed. But a large dental filling can weaken the remaining structure of the tooth, causing the tooth to break, crack or eventually need a root canal.
Dental onlays fall somewhere in between dental fillings and dental crowns. Like dental inlays, onlays restore large cavities without having to use a crown.
The dental onlay procedure typically entails:
Indirect Onlays -- During the first appointment, your dentist prepares the tooth by removing any tooth decay. Once the tooth is prepared, an impression is made of the tooth's structure and then sent to a dental laboratory. Since it will take a few weeks to create the onlay, your dentist will place a temporary dental filling to preserve the tooth. During the second dental visit, the temporary filling is removed and the dental onlay is cemented onto the tooth.
Direct Onlays -- For direct dental onlays, the same preparation is used, and the tooth is filled with composite resin material. Traditionally, the filling is molded and hardened in an oven and then cemented to the tooth. But now there's a high-tech option for making direct dental onlays: CEREC® uses 3D computer imagery and other special equipment to produce porcelain restorations right in your dental office. By simply taking a picture of your tooth, your dentist can design and create dental onlays, dental inlays, dental crowns or veneers while you relax in the dental chair -- no impressions, temporary fillings or second appointments are needed!