While small cavities can be filled with composite dental fillings, teeth that are more extensively damaged are treated using a different process. If the damage affects the area between two cusps of a single tooth, your dentist will use an inlay. If the damage only affects one cusp, they will use an onlay.
Inlay restoration is a custom filling made of tooth-coloured porcelain or composite material. Inlays are an ideal alternative to conventional silver fillings and are more conservative than crowns due to less removal of tooth structure during preparation. Highly durable and long-lasting, your inlays may require replacement after normal wear.
Onlays are the same as inlays with the exception that one or more of the chewing cusps have also been affected and will need to be restored. An inlay will fill the space in-between the cusp while the onlay covers the entire biting surface of the tooth. Onlays are sometimes referred to as partial crowns.