An inlay is similar to a filling and inserted inside the cusps (points) of the tooth. When the extent of the tooth damage involves one or more cusps of the tooth or when full coverage of the biting surface is needed, an onlay is recommended.
Onlays can be a very good alternative when the damage to the tooth is not extensive enough to merit an entire crown.
Inlay and Onlay Process and Materials
During the initial visit, 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 prepared tooth is sent to a laboratory for fabrication. A temporary filling is made and temporarily cemented in or on the tooth. At the second appointment, the temporary is removed and the inlay or onlay is fitted then cemented or bonded in place, and polished to a smooth finish.
Porcelain inlays and onlays are more attractive
Inlays and onlays can be made of porcelain, gold or composite resin. Porcelain inlays and onlays are more attractive because the material mimics the enamel’s translucency and color, while gold inlays and onlays are more durable.
Traditional fillings can reduce the strength of a natural tooth by up to 50 percent. A tooth restored with an inlay or onlay can bear up to 50-75 percent more chewing force and can last from 10-30 years.