Crowns are one of the most widely used tools in cosmetic dentistry. Also called "caps," they can be used in a number of ways to remedy broken, chipped, missing or weakened teeth, and improve the appearance of your smile at the same time.
If a tooth decays and requires a large (or several small) fillings, oftentimes there is not enough of the original tooth structure left to support the filling and maintain the integrity of the tooth. In this case, what remains of the original tooth is prepared to accept a crown. This is done by reducing the tooth slightly and shaping it to hold the crown in place. At this point an impression is taken to allow the new crown to be constructed with a precise and customized fit. While waiting for the dental lab to construct the new crown, a temporary crown is put in place. The permanent crown is made to the exact specifications of the impression taken, because it is very important that the permanent crown fit snugly and securely. This precise fit ensures that food is unable to get in beneath the crown and that the crown functions seamlessly as an extension of the natural tooth surface. The permanent crown is cemented into place and the integrity and appearance of your tooth is restored.
Generally, crowns are made of a porcelain or composite overlay on a metal base. This combines the strength of the metal base with the natural appearance of the porcelain, and creates a durable repair and a pleasing appearance. Originally, gold crowns were often used on back teeth for strength, but with the durable nature of the new materials used today, this is rarely necessary. In most cases, you can expect your crown to last 10 to 15 years or sometimes appreciably longer, considerably longer than a weakened tooth, and allowing you to avoid losing your natural tooth.
Crowns are also used in conjunction with a bridge when you have a missing tooth, and an implant is not indicated. The bridge ( or false tooth) is anchored to the remaining teeth on either side by means of crowns. These fixed bridges are permanent and are often preferable to a partial denture which sometimes lacks the natural appearance or is not as comfortable as the fixed bridge. In most cases, your bridge will look and feel just like your natural tooth, and eliminates the inconvenience of a partial. Keep in mind that, since your bridge and crowns are supported by natural teeth and bone, it is essential to maintain good dental hygiene - including flossing - to extend the life of your crowns and bridge as long as possible.