When a tooth is badly decayed or damaged a tooth shaped covering called crown is used to cover the tooth. Crowns are used in situations where the tooth cannot be replaced by fillings or other methods. Misshapen and discolored tooth can maybe covered by crowns. Parts of a cracked tooth or a bridge can be held together by a crown.

If large amount of decay is there, a root canal treatment maybe needed prior to placing of the crown. A foundation is built up first to support the crown. The tooth is filed down so that there is enough room for placing the crown. The impressions of the teeth are taken and sent to lab for manufacturing the crowns as per requirement. Firstly a temporary crown is placed on the tooth until the permanent one is manufactured.

Temporary crowns can be made in the dentist's office itself and are made of plastic, acrylic or stainless steel. Permanent crowns may be broadly classified as:

  • Stainless steel crowns
    These crowns are normally prefabricated and used as temporary crowns to protect the teeth while the permanent one is being made. These are commonly used in children to protect the primary teeth from decaying further until the permanent tooth comes out. They are cost effective when compared to custom made ones.

  • Porcelain fused to metal crowns
    These are custom made to match the natural color of the teeth. They look the same way as normal teeth. But the major drawback of this crown is that it causes more wearing of the opposing tooth. The porcelain portion of the crown may chip or break off as well.

  • Metal crowns
    Generally metal crowns are made from gold alloy or other alloys of metals like palladium chromium, nickel etc. In case of metal crowns less modification of tooth structure is needed and wearing of the opposing tooth is also reduced. They have longer life and don't break easily. The only drawback is the metallic color that makes it conspicuous.

  • All resin crowns
    These are dental crowns used for temporary purposes mostly as they are more prone to cracks and fractures.

  • All ceramic crowns
    Made completely from ceramics or porcelain these provide more color and natural look than other crown types. However, unlike porcelain fused metal crowns they are not strong enough; and is the best suited for person with allergies to metals. They wear down the teeth more. For front teeth, all ceramic crowns are the best choice.

Crowns often last for at least seven years and more. A crown protects the tooth from decay but not from gum diseases. Also it is necessary to use a fluoride gel to prevent cavities from developing.