Treat severe cavities on the rear teeth.
Inlays or onlays are typically used when cavities on the chewing surface of back teeth have become too severe to be treated with traditional fillings. The difference between inlays and onlays is determined by the positioning of the damage in regards to the chewing surface of the tooth. If the damage is restricted to within the depression surface of the tooth (within the cusps) it is an inlay. If more extensive damage has progressed and the cusps must be recreated, it becomes an onlay.
Inlays and onlays can be created using gold, porcelain, or a composite resin colored to match your natural tooth. The latter two options are the most popular today due to their aesthetic appearance, but gold is still one of the strongest options. These restorations are a two-step process. First the tooth is prepared by removing decay or old materials then an impression is taken of the affected area. The impression molds are sent to a dental laboratory where a skilled technician fabricates the restoration. At the next appointment the inlay or onlay is cemented into place.