When a tooth is heavily damaged by decay or trauma it may be left with a very large filling. Large fillings can sometimes be structurally weak and prone to fracture. A crown is a tooth-shaped shell placed over a tooth to preserve it and prevent fractures or mask it for cosmetic reasons. Crowns can be made of a variety of materials depending where they are to be placed in the mouth.
Gold and metal crowns offer very high strength and durability at the back of the mouth where biting forces are greatest. Tooth coloured porcelain is used at the front of the mouth to give excellent aesthetics and natural tooth characteristics to create flawless smiles.
The life expectancy of a crown varies, depending on oral hygiene and the material used. Crowns can sometimes be damaged by bad habits like opening bottles, so it is imperative they are well looked after and maintained through regular check-ups.
For more information on crowns, click here (requires Adobe Acrobat).