|A crown restores a tooth by covering the entire chewing surface. Crowns cover, protect, seal and prevent a tooth from fracturing. Once a filling is too large to predictably last a long time a crown is recommended. A crown can be made of different materials such as gold and porcelain. At Clark & Eldredge Dental in Corvallis, Oregon we generally use a porcelain that can be manufactured the same day so the entire crown can be completed in one convenient visit. There are many situations that may call for a crown:
If a tooth has decay so deep and large that a filling
will not predictably last a long time without breaking, a crown is recommended.
|Large old fillings.
When large old fillings break down, or get decay around them, they usually need to be crowned. It is important to crown a tooth that has been structurally weakened to prevent a cracked or broken tooth. Once a tooth breaks, it may not be possible to save it.
When a tooth is cracked, a filling
will not seal the crack. A crown has to be placed over the tooth to hold it and the crack together. If a crown is not placed on the tooth, the tooth will become sensitive to chewing pressure, or will eventually break. It is important to crown a cracked tooth before it breaks, because in some cases a broken tooth cannot be crowned and must be extracted.
Broken / Fractured tooth.
A tooth that has broken is usually too weak to hold
a filling. A crown will hold the tooth together and prevent it from breaking again. If the fracture involves the nerve, Root
Canal Therapy may be required before the tooth is
crowned. In some cases, a broken tooth cannot be saved
and must be extracted.
|This patient chose not to have the cracked tooth above crowned, and it later fractured. This tooth had to be extracted because it cracked all the way to the root.
Teeth that are very sensitive, either from a lot of "wear", or from receded gums, sometimes require crowns to seal and protect the teeth from hot and cold sensitivity.
Root Canal Therapy.
A tooth that has undergone Root Canal Therapy will need a crown to properly seal and protect the tooth. A tooth with Root Canal Therapy is more brittle than a tooth with a healthy nerve and blood supply. A crown provides the necessary support to the tooth.
In cosmetic dentistry, crowns (sometimes
called "caps") are used less frequently
since the advent of veneers,
but in some cases a crown may be necessary for a particular
tooth. A tooth with a bad fracture
or a large filling may be
a candidate for a crown instead of a veneer.
|Before: This tooth has a large filling
as shown. A crown is needed on this tooth, instead
of a veneer, because there isn't enough natural
tooth left to support a veneer. A crown will cover
and protect the tooth, but will look the same as
|After: The top teeth now have veneers,
except the one that had the large filling, which
now has a crown.
Replacement of many unnatural crowns with a modern material