Odontologia

decreased tooth stiffness by 63%. We suggest that it is rather the cumulative loss of tooth structure from caries, trauma, and restorative and endodontic procedures that leads to susceptibility to fracture. Another possibility that has been suggested but never extensively explored is that loss of pressoreception (19), or an elevated pain threshold (20) allows larger loads on endodontically treated teeth without triggering a protective response. This project was supported by a grant from the National Health and Medical Research Council of Australia and was based on a thesis submitted to the University of Melbourne in partial fulfillment of the requirements for the MDSc degree. The authors gratefully acknowledge the technical assistance of David Cheadie and Koren Mitchell of the School of Dental Science, University of Melbourne, Melbourne, Australia. Dr. Sedgley is a graduate student in endodontics, School of Dental Science, University of Melbourne, Melbourne, Australia. Dr. Messer is professor of Restorative Dentistry, School of Dental Science, University of Melbourne. References 1. Rosen H. Operative procedures on mutilated endodontically treated teeth. J Prosthet Dent 1961;11:972-86. 2. Johnson JK, Schwartz NL, Blackwell RT. Evaluation and restoration of endodontically treated posterior teeth_ J Am Dent Assoc 1976;93:597-605. 3. Greenfeld RS, Marshall FJ. Factors affecting dowel (post) selection and use in endodontically treated teeth. J Can Dent Assoc…