Crowns are used to restore broken or badly decayed teeth, when the damage exceeds the limits of what bonding alone can repair. Traditional (older) crowns were fabricated with an inner metal core or sometimes were completely metal. Unfortunately, the metal blocks light from passing through the tooth. This makes the whole tooth and root appear very dark. With time the gums would recede exposing the distinctive black line that is the inner metal layer. Newer porcelain materials are much stronger, eliminating the need for the metal layer. Since porcelain is translucent it allows light to pass into the tooth making it appear indistinguishable from natural tooth enamel.
At the first appointment, all decay and previous restorative material is removed from the tooth. Sometimes, if a lot of tooth structure has been lost from the decay process, an additional procedure called a crown buildup is completed to assure the new crown has a proper foundation to sit on. An impression of the tooth is made and sent to the dental lab. A temporary crown is made and placed over the tooth for 2-3 weeks while the final crown is being made in the lab.
On the second visit, the temporary crown is first removed and the tooth is cleaned. The new crown is tried-in and adjusted for fit, comfort and esthetics. Once any adjustments have been made, the crown is cemented and the tooth is restored to full function and esthetics.