When faced with the challenge of restoring an endodontically treated tooth, the dentist must decide, first, whether the post is required and second, the type of restoration that is indicated. Earlier a post was thought to strengthen the root of an endodontically treated tooth. But it is widely held today that the primary purpose of post placement is to retain the core buildup material or to reinforce the remaining coronal tooth structure. It is difficult to discuss the longevity of teeth restored by a post because there are many variables to control. The long term clinical success of an endodontically treated tooth is dependent on many factors. The successful treatment of a badly broken down tooth with pulpal disease depends not only on good endodontic therapy, but also on good prosthetic reconstruction of the tooth after endodontic therapy is completed. The decision to place a post is based on several parameters. These include the position of the tooth in the arch, occlusion, function of the restored tooth, amount of remaining tooth structure and canal configuration.