Crowns, also known as “caps,” are a type of restoration that can help to protect teeth that have become damaged, broken or cracked. Instead of replacing the tooth, a crown is used to strengthen the existing tooth and preserve its usefulness. 

Your teeth may require a crown if the damage is great enough that the remaining part of the tooth is too weak to support a filling. Crowns are also used to strengthen teeth after certain dental treatments like root canals.

Why Is a Dental Crown Needed?

A dental crown may be needed in the following situations:

• To protect a weak tooth (for instance, from decay) from breaking or to hold together parts of a cracked tooth
• To restore an already broken tooth or a tooth that has been severely worn down
• To cover and support a tooth with a large filling when there isn't a lot of tooth left
• To hold a dental bridge in place
• To cover misshapen or severely discolored teeth
• To cover a dental implant

What Types of Crowns Are Available?

Permanent crowns can be made from all metal, porcelain-fused-to-metal, or all ceramic.

• Metals used in crowns include gold alloy and other alloys (for example, palladium and platinum) Compared with other crown types, less tooth structure needs to be removed with metal crowns, and tooth wear to opposing teeth is kept to a minimum. Metal crowns withstand biting and chewing forces well and probably last the longest in terms of wear down. Also, metal crowns rarely chip or break. The metallic color is the main drawback. Metal crowns are a good choice for out-of-sight molars.
  
  
• Porcelain-fused-to-metal dental crowns can be matched to the shade of your adjacent teeth (unlike the metallic crowns). However, more wearing to the opposing teeth occurs with this crown type compared with metal crowns. The crown's porcelain portion can also chip or break off. Next to all-ceramic crowns, porcelain-fused-to-metal crowns look most like normal teeth. However, sometimes the metal underlying the crown's porcelain can show through as a dark line, especially at the gum line. These crowns can be a good choice for front or back teeth.
  
  
• All-ceramic or all-porcelain dental crowns provide the best natural color match than any other crown type and may be more suitable for people with metal allergies. However, they are not as strong as porcelain-fused-to-metal crowns and they wear down opposing teeth a little more than metal crowns. All-ceramic crowns are a good choice for front teeth.
  
  
• Temporary versus permanent. Temporary crowns can be made in your dentist's office whereas permanent crowns are made in a dental laboratory. Temporary crowns are made of acrylic or stainless steel and can be used as a temporary restoration until a permanent crown is constructed by the dental laboratory.A process that typically takes approximately 2 weeks.