When more than half of a tooth’s biting surface is damaged, an inlay or onlay may be the recommended treatment.
Inlays and onlays are used to replace damaged areas of the tooth, and can be made of porcelain, gold or composite resin. An inlay, which is similar to a filling, is used inside the cusp tips of the tooth. An onlay is a more substantial reconstruction, similar to the inlay but extending out over one or more of the cusps of the tooth.
Traditionally, gold has been the material of choice for inlays and onlays, however porcelain has become increasingly popular due to its strength and color, which can closely match the natural color of your teeth.
Inlays and onlays require two appointments. During the first visit, the filling being replaced or the damaged or decaying area of the tooth is removed, and the tooth is prepared for the inlay or onlay. To ensure proper fit and bite, an impression of the tooth is made by the dentist, and sent to a lab for fabrication. The dentist will then apply a temporary sealant on the tooth and schedule the next appointment.
At the second appointment, the temporary sealant is removed and we will make sure that the inlay or onlay fits correctly. Once the correct fit is achieved, the inlay or onlay is bonded to the tooth with a strong resin and polished to a smooth finish.
Traditional fillings can reduce the strength of a natural tooth by up to 50 percent. Inlays and onlays on the other hand, which are bonded directly to the tooth with special high-strength resins, can actually increase the strength of a tooth by up to 75 percent. As a result, they can last from 10 to 30 years. In some cases, where the damage to the tooth is not extensive enough to require a crown, an onlay provides a very good alternative.