What are crowns and why are they used?

A crown is a restoration that covers, or caps, a tooth to restore it to its normal shape and size. Its purpose is to strengthen or improve the appearance of a tooth. Crowns are placed for a variety of reason. Crowns can:

• Restore teeth when there isn't enough tooth remaining to provide support for large fillings
• Attach bridges
• Protect weak teeth from fracturing
• Restore fractured teeth
• Cover badly shaped or discolored teeth
• Cover dental implants

Which material is best?

Both the "look" and function of a crown are considered when choosing the materials most suitable for you. Your dentist will consider the tooth location, the position of the gum tissue, the amount of tooth that shows when you smile, the color or shade of the tooth, and the function of the tooth.

Crowns are made from a number of materials. Gold alloys or non-precious alloys, porcelain or ceramic, composite resin, or combinations of these materials may be used. Full metal crowns are stronger but not as esthetically pleasing; porcelain crowns are not as strong as full metal crowns. Crowns made entirely of porcelain may look better, and they are stronger than they used to be, but still are not as strong as the other materials. In the process of making a crown, the material is colored to blend in with your natural teeth. It is important to consult with your dentist as to which crown materials are best for your specific situation.

How is a crown placed?

The placement of a crown is a precision procedure. Several steps are involved, and at least two dental visits usually are necessary for completion. The dentist will prepare the tooth by removing its outer portion to accomodate the thickness of the crown. If the tooth has a filling, part of the material may be left in place to serve as a foundation for the crown. An impression is made to provide an exact model of the prepared tooth. Your dentist or a dental laboratory technician, following the written instructions of the dentist, will then make the crown from the model. "Temporary" crowns are placed while the permanent crown is made. If the shapes or lenghths of your teeth are changed for cosmetic purposes, temporary crowns will allow you to become accustomed to these changes. Temporary crowns also can help you decide if you like what you see or if there are any changes you would like made before the finished crowns are placed.

When the finished crown is ready, the dentist puts it in place and makes ncessary adjustments. To see how your own crown will look, you can use a large mirror held at arms' length in various types of lighting. When you and your dentist are satisfied with its appearance, the crown will be cemented in place.

Your dentist can provide you with more information on the use and care of crowns.