How Crowns and Bridges are Made
First, why do we need crowns and bridges? A crown is called for when a tooth is broken, or is so decayed that it can’t handle that much filling without being weak. And sometimes, a crown is used if a tooth is severely discolored or misshapen. Another use is to have a crown on either side of a bridge, for support.
With a bridge, one or more teeth are completely gone, or there’s not enough tooth left to put a crown on, and the space needs to be filled.
Crowns can be constructed with several different materials. But the most common are gold and porcelain.
- Gold is typically used on back teeth only, where it won’t be seen that much. Its main advantage over porcelain is strength. Also, less tooth will need to be minimized before the impression and fitting are done.
Another advantage of gold is in the lab–it shrinks less when cast and is easier to polish.
- Porcelain is just about always used for front teeth, but can be used for back teeth. Porcelain’s advantage is appearance. It’s made to look, size and color, just like the rest of the teeth in your mouth. That said, occasionally some porcelain crowns have metal inside to give strength and support, but it can give the crown a dull color. While this isn’t a problem with back teeth, it definitely IS with front teeth.
At first, before the crown can be constructed, the original tooth must be minimized so that the crown will fit over it. The dentist will, using his drill, reduce the tooth in size. Then he/she takes an impression so an exact mold for the crown is possible. Also, if porcelain is to be used, a determination is made on exact shade to match your other teeth.
A dental lab, after receiving the information and impression, will begin the process of making your crown. But first, a temporary crown will be put in to cap the drilled down tooth, to protect it while the real crown is being made. After a week or two, you will then receive your new crown, placed permanently over your minimized tooth.
They’re constructed in basically the same way. There is still the desire to match the shade of the surrounding teeth. Bridges are usually porcelain—seldom gold.
Usually, the teeth on either side of the open space will need to have crowns placed on them, for added support for the bridge. And again, a temporary bridge will be used first. Then a permanent tooth will be suspended between the two crowns and attached.
It’s important to get a missing tooth bridged, because if a tooth is missing, the surrounding teeth will shift to fill the space, and could easily become crooked, and will give you a bad, unbalanced bite.
Then you could be looking at gum disease or temporomandibular joint (TMJ) disorders.