|A crown fits over the entire top of the tooth above
the gum line. Crowns cover, protect, seal and strengthen
a tooth. A crown is needed when a filling just will not
work. A crown may be made of gold, white porcelain, or
porcelain fused to gold. There are many situations that
may call for a crown:
|Large decay. If a
tooth has decay so deep and large that a filling will
not stay, or if the tooth structure is weakened, a crown
must be placed on the tooth to save it.
|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.
|Cracked tooth. 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
|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.