Post and Core Buildup
A post and core (colloquially known as a "post" or "dental post") is a type of dental restoration used either to stabilize a weakened tooth or provide an anchor for a crown. Utilized when inadequate tooth structure remains to support a traditional restoration, it consists of the insertion of a small rod (known as a "post") into the root space of an affected tooth, leaving several millimeters protruding. The protrusion is then used to support a large filling, or anchor a crown.
Post and cores divide into two main groups: prefabricated and cast. Both of these systems employ a post that is placed within the root canal of the tooth being restored. Thus the tooth must first be endodontically treated. After the endodontic procedure has been completed, and the root canal(s) is/are filled with the inert gutta percha root canal filling material, some gutta percha is removed from the canal space, usually by a series of endodontic files that prepares and shapes the root canal. The space that exists coronal to the remaining gutta percha, called the post space, is now available within which to place a post. It is desirable to leave sufficient root filling material in the apical area to maintain an apical seal. This procedure does not even require local anesthesia as the tooth has long been dead after the root canal treatment and no pain is felt.