If more than half of the tooths biting surface is damaged, we will often use an inlay/onlay. Inlays/onlays can be made of porcelain, gold, or composite resin. They are bonded to the damaged area of the tooth. 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 extends out over one or more of the cusps of the tooth.
Traditionally, gold has been the material of choice for inlays/onlays. In recent years, however, porcelain has become increasingly popular due to its strength and color which can potentially match the natural color of your teeth.
Traditional fillings can reduce the strength of a natural tooth by up to 50 percent. But inlays/onlays that are bonded directly onto the tooth using 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 your tooth damage is not extensive enough to merit an entire crown, onlays can are a very good alternative.
How are they applied?
It takes two appointments to apply an inlay/onlay. During the first visit, we remove the old filling or the damaged or decaying area of the tooth. To ensure proper fit and bite, we make an impression of the tooth. We then send this impression to a lab for fabrication. After that we will apply a temporary sealant on the tooth and schedule another appointment.
At your second appointment we remove the temporary sealant. Then we make sure that the inlay/onlay fits correctly. If the fit is satisfactory, the inlay/onlay will be bonded to the tooth with a strong resin and polished to a smooth finish.