Onlays are located on the top of the tooth, including the cusps (bumps on top of the tooth), and are mainly used for cosmetic or restorative work.  These onlays are composed of non-metallic or porcelain material and are natural looking.  Even though the amount of the existing damaged part of the tooth that must be removed is minimal, onlays may extend over one or more sides of a tooth and are used most often for a crown or cap.

As with most dental procedures, an impression of the tooth is taken and used to create the custom piece.  Onlays may also be used in cases of filling or crown replacements, cavities, and various other possibilities..  Until the permanent onlay is ready to be installed and permanently bonded to the tooth, a temporary onlay is used.