What is a crown?
A dental crown (also sometimes referred to as a "cap") is a tooth-shaped restoration that is placed over the tooth - covering it to restore the shape, size, strength, durability, stability and/or to improve the tooth's appearance due to discoloration.

Am I a candidate for a Crown?

Grinding your teeth, an improper bite, age, fillings and tooth decay can all be contributing factors in the wearing down, cracking or breakage of your teeth. To prevent further damage, dental crowns may be the answer to your needs. Crowns are used to repair teeth that have undergone root canal treatment, have severe erosion, or extremely malpositioned. Surprisingly, even teeth that have broken off flat at the gum line can usually be rebuilt with a crown.

Types of crowns

• The most common type of crown used in dentistry today is porcelain covering precious metal. These crowns are durable and esthetic, but can, after several years, expose an unsightly gray line around the edge of the crown. The all porcelain crown typically has the most natural look, but is not as durable as the other types of crowns. All porcelain crowns are usually advised for teeth in the front of the mouth, namely the incisors and canines where the translucency enhances its appearance. All gold crowns are strong, adapt tightly to the tooth, are very well tolerated by the gums and other soft tissues in the mouth, and do not tend to wear the tooth they bite against to any noticeable degree. All gold crowns usually cost about the same as porcelain covering gold crowns, but are not considered cosmetically acceptable to many patients.

The newest type of crown is the porcelain covering 88% yellow gold, or the Captek crown. These crowns are very durable and cosmetically superior to all other crowns except the all porcelain crown. The Captek crown will not expose a grey or black line over time like the porcelain covering precious metal sometimes will, and can also be used in the front of the mouth in situations when all porcelain can not be used. People with powerful jaws and teeth that come together edge-to-edge as well as those whose teeth are badly discolored may not be good candidates for all porcelain crowns due to their lack of strength. In these situations, and when both strength and esthetics are high priorities, the Captek crown would be the treatment of choice.

"Capping" a tooth requires buffing away relatively large portion of the tooth structure. Thus it is utilized as a way to improve the cosmetic appearance only when it simultaneously serves other purposes, such as restoring a tooth to its original shape (repairing a broken tooth) or strengthening a tooth (covering over a tooth which has an excessively large filling). In the cases where esthetics is the only concern the most reasonable restoration will be porcelain veneer (to restore front teeth) or onlay/inlay (to restore back teeth). They are much more conservative and will give the same longevity.

Crown vs. Filling

The advantage of a crown can be compared to a dental filling. With dental fillings, especially large ones, they often have a weakening effect on teeth. Dental fillings rely on a tooth's remaining structure to hold and support them. Any filling which is greater than about a third of the width of its tooth could be considered to be a filling large enough that the strength of the tooth overall has been reduced and the tooth is now a good candidate for the placement of a dental crown. Fillings, in general, don't strengthen a tooth and don't protect a tooth from the forces generated by biting and chewing.

How Long Does It Last?

On average, dental crowns last between 5 and 15 years. The life span of a crown depends on the amount of "wear and tear" the crown is exposed to, how well you follow good oral hygiene practices, and your personal mouth-related habits (you should avoid such habits as grinding or clenching your teeth, chewing ice, biting your fingernails and using your teeth to open packaging).

Crown Preparation

Prior to preparing a tooth for a crown the dentist may take a few x-rays to check the roots of the tooth receiving the crown and surrounding bone. If the tooth has extensive decay or if there is a risk of infection or injury to the tooth's pulp, a root canal treatment may first be performed.

Preparing a tooth for a crown usually requires two visits - the first step involves preparing the tooth, the second visit involves placement of the permanent crown. At the first visit, the natural tooth is prepared by reducing its size along the chewing surface and sides. Because the crown is about two millimeters thick, which is just a little more than a sixteenth of an inch, the dentist shaves this same amount off. This will avoid awkward-looking, oversized teeth. As a part of the trimming process your dentist will ensure that any and all decay has been removed from your tooth. If, on the other hand, a large area of the tooth is missing, your dentist will use filling material to "build up" the tooth enough to support the crown. Finally, the dentist will also re-shape your tooth into a form upon which a cap can easily sit.