WHAT IS A CROWN?
Crowns are full coverage restorations that are used to cover a tooth that is likely to break, or is too broken down to be restored with a filling. They are most commonly done after root canal treatment, or when a large filling wears out. The larger the hole made by a cavity that has to be treated, the more likely a crown will be needed. Even after a filling is put in a large cavity, a tooth is more likely to break. Keep in mind that the jaw muscles are the strongest in the human body. Teeth are subjected to tremendous pressures. Crowns ride over the weakened tooth, providing strength and protecting the tooth against breakage. A broken or cracked tooth is a far more serious matter and much more difficult to treat. Crowns prevent this, as well as making for a nice smile.
WHAT ARE THE BENEFITS OF A CROWN?
Before crowns, the only real option for a broken down tooth was extraction. Crowns have given dentists, and in turn patients, the ability to fix certain dental situations.
Cavities, or dental decay, occurs when acid-forming bacteria in the mouth are supplied with sugars. With these sugars as their food, the bacteria produce acid that eats away at the tooth, creating cavities. Usually, cavities can be drilled out and filled with tooth-colored composite (or silver amalgam) fillings. However once too much tooth structure is lost, fillings will no longer suffice and the tooth will need to either be extracted or crowned.
In addition to cavities, age, wear, and fracture are other reasons a tooth may require a crown. With age, teeth tend to turn yellow, wear down, chip, and become less attractive. In addition, teeth can fracture from over-use or by accident. In these situations as well, crowns are a great way to restore function, esthetics, and beauty to a smile.
It takes two appointments to restore a tooth with a crown. In the first any decay is removed from the tooth and it is shaped to accept the crown. Then an impression is made of the tooth for use in fabricating a crown. Between the two visits the crown is made, usually of high-strength porcelain over gold alloy, all ceramic material, or gold. During this time a temporary crown is worn. In the second visit this temporary is removed. Then the permanent crown is adjusted as needed and then cemented in place.