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CONTENTS
Introduction History Key words and definitions Consideration in restoring endodontically treated teeth. Effects of endodontic treatment Anatomic and biologic considerations. Indications and contraindications. Ideal requirements of post core. Classification of post core. Treatment planning Stress analysis for post and cores Factors influencing retension and resistance. Principles of preparation of endodontically treated teeth. Custom made post core Prefabricated systems Provisional restorations Advances in post core system. Removal of existing posts Success and failure of post cores. Conclusion Review of literature References.
INTRODUCTION: “Teeth and artificial dentures, fastened with posts and gold wire, hold setter than all others. They sometimes last fifteen to twenty years and even more without displacement . . .” Piree Fauchard – 1747. Restorative dentistry and endodontics have reached a point where they enjoy a symbiotic relationship. Endodontic treatment saves the tooth from extraction but only adequate restoration will reinstate it as a long-term functioning member of the mouth. The restoration of a tooth by root canal treatment is of limited value unless the crown of tooth is satisfactorily restored. The manner in which a root canal filled tooth is restored is therefore considerable importance. The restoration of the endodontically treated tooth is a subject that has been evaluated and discussed widely in the dental literature. The restoration of endodontically treated tooth is complicated by the fact that much or all of the coronal tooth structure which normally would be used in the retention of the restoration has been destroyed by caries, previous restorations, trauma, and the endodontic access preparation itself. The endodontically treated tooth is a unique subset of teeth requiring restoration because of several factors such as dehydrated dentin, decreased, decreased structural integrity and impaired neurosensory feed back mechanism when compared to a vital tooth. However, the treatment goal must be based upon a multitude of factors specific for each patient, so that the strategic architectural aspects that have/greatest impact on the ultimate strength of the pulpless tooth can be restored/reinforced. Solution to this problem has challenged the inventiveness and ingenuity of dentists for centuries. The endodontically treated tooth must be fortified in such a way that it will withstand both vertical and lateral forces and not be subject d to fracture. Amalgam as routinely used to restore a tooth is not considered the best choice, since the cusps are left unprotected and are subjected to vertical fracture. The use of a crown over an endodontically treated tooth, by itself is not recommended. Further reduction of already undermined walls may render the treated tooth subject to horizontal fracture at or near the gingival line. An inlay, in so far as it too is an intracoronal restoration, leads to same weakness as the amalgam. This leaves the consideration an onlay, which covers the cusps and protects against vertical fracture. Still the potential for horizontal fracture remains, since the pulp chamber is usually undermined. For these