When a larger cavity has appeared in the enamel of the tooth (an outer white part), it threatens the general health and life quality of a person. If the cavity is not treated, it can grow and reach the inner part of the tooth (dentin or even the pulp) where it causes pain and can even lead to infection and dying of the tooth. People who have damaged, chipped, irregularly shaped teeth need crowns to restore the natural shape of those teeth.
Crowns are coverings that are placed over the natural part of the tooth. They are used to give back the proper function and aesthetics to the tooth. Crowns can be fabricated from different materials, with major groups being gold crowns, porcelain crowns and non-metal crowns. Gold crowns are most durable, but are aesthetically outdated. Porcelain crowns are actually made out of porcelain-based outer layer, and a metal-based inner layer that is coated on the tooth. They are stable, hypoallergenic, and very aesthetic crowns. Zircon crowns are the most popular non-metal crowns. They are made out of zirconium oxide, stable and aesthetically very much alike porcelain crowns.