Crowns

What materials are in a Tooth Supported Crown?

Crowns are made of three types of materials:

• Porcelain - most like a natural tooth in color
• Gold Alloy - strongest and most conservative in its preparation
• Porcelain fused to an inner core of gold alloy (Porcelain Fused to Metal or “PFM”) - combines strength and aesthetics

What are the benefits of having a Tooth Supported Crown?

Crowns restore a tooth to its natural size, shape and—if using porcelain—color. They improve the strength, function and appearance of a broken down tooth that may otherwise be lost. They may also be designed to decrease the risk of root decay.

What are the risks of having a Tooth Supported Crown?

In having a crown, some inherent risks exist both to the tooth and to the crown itself. The risks to the tooth are:

• Preparation for a crown weakens tooth structure and permanently alters the tooth underneath the crown
• Preparing for and placing a crown can irritate the tooth and cause “post-operative” sensitivity, which may last up to 3 months
• The tooth underneath the crown may need a root canal treatment about 6% of the time during the lifetime of the tooth
• If the cement seal at the edge of the crown is lost, decay may form at the juncture of the crown and tooth

The risks to the crown are:

• Porcelain may chip and metal may wear over time
• If the tooth needs a root canal treatment after the crown is permanently cemented, the procedure may fracture the crown and the crown may need to be replaced.

What are the alternatives to Tooth Supported Crowns?

Alternatives to crowns are fillings, such as composite or silver amalgam. These restorations remove decay and may restore teeth to their original form, but are limited because they do not improve the strength of broken down teeth. They also do not decrease the risk of root decay or improve the long term function and aesthetics of broken down teeth or crowns.

How can an existing bite affect a Tooth Supported Crown?

• Excessive bite forces may lead to the tooth under the crown breaking or loosening
• Excessive bite forces may lead to the crown chipping, breaking or loosening

Are there any post-treatment limitations once I have a Tooth Supported Crown?

• Porcelain on a crown may have a good color match with adjacent natural teeth when the crown is placed, but less of a match as your natural teeth age
• Gum recession may lead to unsightly dark roots or crown margins becoming visible
• A crown may chip or break if used for abnormal activities (e.g., biting fishing line, sewing thread or finger nails, opening bottles)

What can I expect when I go to the dentist for having a crown placed on my tooth?

Some crowns require two appointments and some can be made and placed in a single visit. If your dentist has decided to place a crown which requires two separate visits the first appointment will be much like having a filling done. You will be given anesthetic for comfort and the dentist will prepare the tooth for the crown. The dentist will then take an impression of the tooth to be crowned. Finally a temporary crown will be placed on your prepared tooth for aesthetics, comfort, and function until your permanent crown is ready and can replace it. In about a week you will have a second appointment in which your dentist will remove the temporary crown, fine tune your permanent crown, then cement it in place.

If your dentist chooses to use a crown which can be made in a single visit, the first steps in the appointment will be very similar, except that you will have a digital impression taken of your tooth rather than a silicone one. No temporary crown will be needed as you will not have to wait long for the permanent crown. The dentist will then use the digital impression to design a customized crown for your tooth and have it milled in house. They will return with the crown and cement it in place similarly to the second appointment mentioned above.