A post is placed in a tooth that has been root canal-ed, in order to reinforce the now weaken, and hollowed out tooth. Is is like putting re-bar in concrete. Because a tooth with a root canal has no blood flow, it is technically dead, and will become brittle. With out the post, it could break off at the gum line.
There are two types of posts that we generally use:
1.The first is a prefabricated, fiberglass post. This type of post works best when the tooth still has a good structure, and hasn’t been weakened too much, after the decay has all been drilled out.
2.The other type of post is a cast post, made of metal by the dental lab, to fit precisely inside the tooth. This type of post is the strongest, and is almost always used on molars.
After placing a post, a porcelain crown is usually recommended to seal the tooth.