Inlays and onlays provide a very strong restoration. The tooth is prepared and an impression is made of the prepared tooth. The restoration is then made on a model and is subsequently cemented into the tooth. Inlays are cemented inside the tooth’s walls. Onlays fit both inside and over the top of the tooth’s cusps. This provides strong protection for the tooth as it is used during chewing and biting eliminating the possibilities of the tooth fracturing under those stresses. In situations where decay or old fillings have caused the loss of considerable tooth structure, onlays are much stronger than fillings and more conservative than full crowns. They are an excellent restoration option.