A crown is a protective cap that covers a badly damaged tooth and stops it from breaking. A bridge, on the other hand, joins two or more teeth, often to fill the gap left by a missing tooth. Both can be made from different materials – metal, ceramic or zirconia.
It is advisable to replace permanent crowns and bridges with temporary ones, for several reasons:
-
The adhesive used for braces does not bond as well to the material of crowns and bridges as it does to natural tooth enamel, which can mean the brackets keep coming off.
-
If the teeth under the bridge need to be moved, this will not be possible unless the bridge is replaced with individual crowns.
-
When treatment is finished, the teeth will be in a different position, so the old crown or bridge may no longer fit properly.
-
To bond a bracket to a crown, its surface has to be roughened slightly, which spoils its smooth finish.
Temporary plastic crowns hold brackets better, and once treatment is complete they are replaced with new permanent ones. The same considerations apply to the attachments (buttons) used with clear aligners.
This answer is for general information. Your own case needs an examination by an orthodontist.