Compared to traditional fillings, which are performed in the patient’s mouth, inlays and onlays are indirect restorations. These are custom-made filling material fabricated on a dental cast in the laboratory using gold, composite, porcelain or ceramic.
Inlays are indirect tooth fillings indicated for caries located at the center of the occlusal table. All the walls are intact, so the margins of the filling material are bound by the natural teeth. On the other hand, Onlays are indirect fillings indicated for caries that extend towards one or more walls of the tooth. The margins of the restoration can extend to cover the natural tooth and depending on the decay or fracture, it is often referred to as a partial crown.