Crowns are artificial restorations which cover a tooth to restore it to normal shape and size. They are advised to strengthen the available tooth structure. They are placed for variety of reasons. They can be used to restore teeth when there is not enough tooth remaining to support large fillings. This way they protect weak teeth from fracturing. They are also used to restore already fractured teeth. Badly discolored and mutilated teeth can easily be restored to normal form and function using crowns.

Crowns could be made either in metal, metal-ceramic or all-ceramics. The choice of material depends on the dentist, patient, aesthetics and economics. Today, most patients opt for crowns that match the color of the rest of their teeth.  Some people, however, still prefer to have gold or metal crowns placed over their teeth instead of the more natural looking porcelain varieties. 

All teeth at the back of the mouth that have had root canal treatment should have crowns placed to prevent breakage of the tooth.  These teeth have lost their natural hydrating mechanism and tend to be brittle.  Even if it is adequately filled, the tooth surrounding the filling is likely to break sooner or later as these teeth bear heavy forces during chewing. 

Teeth that are more than half filling material should be crowned too.  Remember that fillings are supposed to be surrounded by tooth structure.  As the filling gets larger, the tooth structure that supports the filling gets smaller, weaker and more brittle. 

Teeth with poor aesthetics generally benefit after they are crowned.  Many times, a patient's front teeth are heavily filled, misshapen, crowded, twisted, and poorly colored.  This is an ideal situation for esthetic crowns on the top front teeth. These cases are quite rewarding for both the dentist and the patient because the patient walks away with a beautiful new smile. 

Patients who wear their teeth down because of bruxism can benefit from placing crowns (with metal substructures) on all their teeth.   

During the procedure, if the tooth is vital, the patient is anesthetized, and the tooth is prepared by "grinding" it with a diamond milling bur on a high speed hand piece. After cutting the preparation, an impression of both the upper and lower teeth is taken.   

This impression is then sent to a lab which specializes in making dental crowns.  It is made of porcelain fused to a metal coping with the shade of the porcelain chosen to match the surrounding teeth as closely as possible. Once the tooth is prepared, and the crown is received back from the lab, it must be cemented ("glued") onto the tooth.  

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