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CROWNS
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 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.
Sensitive
teeth. 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 rarely used
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 a veneer.
After:
The top teeth now have veneers, except the one with the large filling,
which has a crown.
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