Inlays are similar to fillings in that they are placed within the biting surface of the tooth and an onlay covers a larger area of the tooth. More conservative than crowns, inlays and onlays are two techniques of restoring normal tooth structure after decay or other damage.
The process of an inlay/onlay is very similar to that of crowns and bridges in that an impression or mould is taken of the inlay/onlay and sent to a laboratory to be specially made. They are usually made from porcelain or gold. The procedure will need two appointments with the dentist:
On the first visit, the dentist will remove the old filling or decay and take an impression or mould of the tooth. A temporary filling is placed to protect the tooth while the dental technician at the laboratory makes the inlay or onlay. On the second visit, the temporary filling is removed and the inlay or onlay is cemented or bonded to the surface of the tooth.
Unlike standard fillings, inlays and onlays are very durable and can enhance the grinding surfaces of the back teeth.