Dental onlays, which are also called partial crowns, are custom made pieces of porcelain, metal or resin that can be placed over damaged and missing areas of the teeth in order to provide strength and create a normal, healthy appearance. Onlays are most often used when the damage to the tooth is so minor that it does not call for a full crown, or when the damage is arranged in such a way that it is impractical to install a crown.
An onlay may be made from porcelain or composite resin if the patient is concerned about the aesthetics of their smile. Metals such as gold may be used if the onlay will be required to withstand a large amount of pressure since the metals are so strong. Amalgam metal fillings are clearly visible in the mouth, though.
In order to set an onlay in the mouth, the dentist first readies the tooth by removing part of the enamel and any of the destroyed matter that is still in the tooth. Next, a mold is pressed from the tooth. This mold is sent to a manufacturer who will create the onlay. Once the onlay is prepared, it is cemented onto the tooth permanently.
There is very little pain during this procedure and patients have no required recovery time once it is completed. Good hygiene is important to the longevity of the dental onlay. Onlays have one of the longest life spans of indirect restorations, lasting over thirty years.