When more than half of the tooth’s biting surface is damaged, one treatment option is an onlay. 

What Are Inlays and Onlays? 

Inlays and Onlays can be made of porcelain, gold, or composite resin. These conservative restorations replace the missing portion of the tooth and are bonded onto the remaining tooth structure. 

Traditionally, gold has been the material of choice for onlays. In recent years, however, porcelain and composite resin have become increasingly popular because they match the natural color of your teeth. 

How Are They Applied? 

Inlays and Onlays require two appointments. During the first visit, the filling being replaced, or the damaged or decayed area of the tooth, is removed. The tooth is then prepared for the inlay or onlay. An impression of the tooth is taken and sent to a lab for fabrication. A temporary filling is placed on the tooth. 

At the lab, porcelain or composite resin, which is processed under heat and pressure to increase its strength, is fabricated using the model of your tooth to reproduce the tooth’s natural shape and contour. 

At the second appointment, the temporary filling is removed. The doctor seats the inlay or onlay, and if the fit is satisfactory, the inlay or onlay will be bonded to the tooth with a strong resin and polished to a smooth natural finish.

Considerations 

Traditional amalgam fillings can reduce the strength of a natural tooth. As an alternative, inlays and onlays are bonded directly onto the tooth using special high-strength resins that can actually increase the strength of a tooth. Inlays and Onlays can last more than a decade. In some cases where the damage to the tooth is not extensive enough to merit an entire crown, inlays or onlays can provide a very good alternative.