When more than half of the tooth’s biting surface is damaged a dentist will often use an inlay or onlay. These are permanent restorations that have the same strength as a crown removes less tooth structure. In some cases, where the damage to the tooth is not extensive enough to merit an entire crown, onlays can provide a very good alternative. Inlays and onlays can be made of porcelain, gold, or composite resin
Traditionally, gold has been the material of choice for inlays and 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. As an alternative, inlays and onlays, which are bonded directly onto the tooth using special high-strength resins, can actually increase the strength of a tooth by up to 75 percent.