Once root canal treatment has been performed then the tooth must be restored. Root canals are usually performed on teeth that are quite broken down and therefore must be built up to have enough tooth structure available to hold onto a crown. In order to retain the core buildup, many times a post must be placed inside the root canal. This is done by removing a portion of the root canal filling material (the part closest to the tip of the root is left to seal the end) and drilling out the proper size to accept the post (no need to worry about the drilling – remember there is no nerve in a root canal tooth). Then, the dentist chooses one of two types – a cast post and core or a prefabricated post. The cast post and core has advantages in that the core buildup is made as one piece with the post so there is no way for the two to separate. A disadvantage is that it must be fabricated outside of the mouth and therefore cannot be cemented on the same day, however, other provisions must be made to build up the tooth. Some prefabricated posts are metal and some of the newer ones are made of carbon fiber composite. The newer carbon fiber ones have a little bit of give to them and they look promising on possibly reducing root fractures in teeth with posts.