Dental crowns are usually used when there is not enough natural tooth left to retain a composite or amalgam filling. They are also placed on dental implants or on teeth that have undergone endodontic treatment (root canal therapy).
Crowns are most often made from metal alloy or a ceramic. The doctor will recommend the type that she feels is best for you.
Metal crowns are usually cast using a noble metal alloy. They can be either gold colored or silver colored. When the tooth that is to receive a crown can be seen when you are smiling or speaking, the doctor will specify that the dental laboratory coat the crown with porcelain that is colored to match your existing teeth.
Ceramic crowns are growing in popularity. They are most often milled from a block of zirconia that is the same color of your existing teeth. Ceramic crowns are usually harder than natural teeth and are not always the best choice. Patient that brux (grind their teeth) are often not good candidates for ceramic crowns on their posterior (back teeth).
Dr. Knox recommends night guards for patients that grind their teeth at night. While over the counter night guards are available, they are not as durable as laboratory fabricated ones.
Some offices are beginning to fabricate ceramic crowns in their office so that they can prepare the tooth and insert the crown in one appointment. We do not plan to acquire that type of equipment until the doctor is convinced that it will save time and money.
A typical crown requires two appointments. At the first appointment, the tooth is prepared to receive the crown, an impression of the tooth is made, and a temporary crown is made from plastic and placed on the tooth. If the crown is to be tooth colored, a shade guide is used so that the lab can fabricate the crown with the correct color. The impressions are sent with a prescription to a dental lab. We use a lab in New Hampshire.
The crown is inserted at the second appointment which is usually 15 business days after the first appointment. The doctor cements the crown to the tooth after she confirms that it fits properly.