Crowns, also known as caps, are used to restore a tooth when large portions of a tooth are lost or when a tooth is fractured. When a tooth has large aging fillings, a crown is a common solution to restore the tooth. Crowns are made by a technician from a mold of the prepared tooth and then fitted to the tooth at a subsequent appointment. There are many types of crowns available, predominantly porcelain (tooth coloured) and metal (either gold or another metal), to restore a tooth. Unlike fillings, crowns do not deteriorate over time and can last a lifetime if properly maintained.