| What we do – Dental
Problems |
| Crowns and Bridges |
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| What is a crown? |
 A crown is a hollow cap that
fits over a tooth, giving it strength and/or improving
its appearance. The supporting tooth has to be reduced
in size to make room for the crown. Crowns may be made
from a variety of materials. |
| Why has my dentist suggested
a crown? |
Crowns are indicated for
teeth, which are too extensively decayed,
damaged or
discoloured for treatment by other means. |
| Preparing a tooth for a crown |
| The tooth to be crowned may
require root filling or rebuilding with a "build-up
core" material before the dentist drills the tooth
to a "peg" shape for the crown. Tooth preparation
for a crown is normally done under a local anaesthetic
and takes approximately 15 to 45 minutes per tooth. It
should be painless. The dentist then takes an impression
of the prepared tooth/teeth, which is sent to a laboratory
where the crown is made. A temporary crown is then fitted
to maintain the appearance, and keep the tooth comfortable
and in the correct position. |
| Fitting the crown |
| The quality of the final
crown depends both on the skill of the dentist and the
technician. At the fitting visit, the temporary crown
is removed and the new crown tried in, to assess that
it has an adequate appearance, fit, shape, and that the bite or occlusion
is correct. The crown is finally cemented with a dental
cement. |
| How long will a crown or
a bridge last? |
| A well made crown or bridge,
in a situation where the overall dental outlook is favourable,
should last for 10 or more years. |
| Why do crowns fail? |
 Sometimes the supporting
tooth under a crown decays – this is more likely
when the crown does not fit tightly to the underlying
tooth. Some crowns come off repeatedly, even shortly
after being fitted. In these circumstances the reason
for the failure may be a poorly fitting crown, or a crown
shape or bite which is not right for that tooth. In those
circumstances a replacement crown will be required. |
| What are bridges? |
| A bridges is a way of replacing
a missing tooth with a fixed solution. There are many
different designs of bridges, but the most common is
a fixed bridge, which is made by placing crowns on the
teeth either side of the space, and then joining the
crowns together by placing a solid crown in the space
to replace the missing tooth. Because this type of bridge
uses joined crowns, cleaning the teeth in the area will
be more difficult. A well-designed bridge should allow
effective daily cleaning. |
| What goes wrong with bridges? |
| Just like crowns, a bridge
must fit the supporting teeth tightly – if not,
then cleaning the bridge will be difficult and the teeth
supporting the bridge may decay or get gum disease. Sometimes
a bridge will come off repeatedly. This may be due to
a variety of factors but the size, shape, and relationship
to opposing teeth should be considered as possible problems
as well as the way the bridge fits on the supporting
teeth. |
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