A crown, or “cap,” covers a tooth to restore it to normal shape and size and improve its functionality. A crown encases the entire visible part of the tooth to the gum line, protecting it from decay. However, it doesn’t protect against gum disease, so a patient still needs to continue proper oral hygiene.
By Judith Nembhard
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What materials are used?
Crowns can be all metal (including gold alloy), porcelain fused to metal (PFM), or all ceramic. All-metal crowns are stronger and can be a better choice for some back teeth, although modern dental materials continue to evolve and increase in strength allowing for more restorative possibilities that are better esthetically yet still long lasting and strong. PFM and ceramic crowns are great because they are the same color as your natural teeth and can last anywhere between 7 to 40 years. Prefabricated crowns made of stainless steel can be used temporarily until a permanent crown is ready.
What are they for?
Crowns are used to hold bridges in place, cover dental implants, protect weak teeth from breaking, or restore teeth that are already broken. Like veneers, they can also cover discolored or badly shaped teeth; however, they are more frequently used in cases where there is less tooth structure. If you need crowns, you may also need root canal treatment if you have a lot of decay in the tooth. But not every tooth that needs a crown requires a root canal.
What problems might occur?
Any type of crown can sometimes chip or fracture, possibly allowing bacteria to leak in and cause decay, or they can sometimes fall off due to improper fit. If your crown chips or is loose or you are experiencing discomfort or sensitivity, contact your dentist. He or she can correct the problem with bonding or a replacement crown.
What new technologies are available?
Traditionally, crowns have been made by taking impressions. More and more, however, dentists are using CAD/CAM (Computer-Aided Design and Computer-Aided Manufacturing) technology to provide a range of restorations, including crowns. CAD/CAM software uses a picture of the tooth to create a virtual crown in 3-D, and a computer uses the data to mill the crown in just a few minutes. This can allow the dentist to complete your crown in one visit, with no temporaries or return visit later for cementation. In addition, CAD/CAM crowns can often be made while preserving more of the existing tooth than was possible in the past.