Crowns and onlays are used to reconstruct a tooth when half or more of it is broken or filled.
Whenever possible we use pure porcelain (CEREC 3D or zirconia) to make crowns and onlays because it is the most bio-compatible and aesthetic material available that looks, feels and is as strong as a real tooth. Sometimes gold, which is very bio-compatible and strong, is used in situations where porcelain is not suitable.
Onlays are a partial crown that maximises the amount of original tooth structure that is kept intact. It is more complex for the dentist to prepare, manufacture and bond than is the case with a full crown, but we recommend onlays where possible because it is the more minimally invasive option for you.