P Amini - Assistant Professor of Prosthodontic, School of Dentistry, Kerman University of Medical Sciences, Kerman, Iran
F Jahani Moghaddam - Assistant Professor of Pedodontics, School of Dentistry, Kerman University of Medical Sciences, Kerman, Iran.

Introduction: The restoration material commonly used as core material for pulpless posterior teeth is mostly amalgam due to its high strength and low cost and it can be used with or without pin. The aim of this study was to evaluate the influence of post material on stress distribution in mandibular second premolar tooth by finite element analysis. Method: The stress distribution was analyzed in amalgam core supported with and without pin. Three dimensional plane strain models of the human mandibular second premolar were first made with pin amalgam and then with post amalgam. After applying the loading force at ۴۵ degree angel, the stress distribution was analyzed in models. Results: Maximum stress in pin amalgam was more than that in post amalgam. The area of maximum stress in pin amalgam was at pin and core interface but in post amalgam it was at the margin of core in the side of applied force. The least stress was at the margin of core opposite to the side of force in both models and was more in pin amalgam than post amalgam. Conclusion: As the stress was more in pin amalgam than post amalgam so it can be said that the fracture strength of post amalgam is more than pin amalgam. Since crown increases fracture resistance of post and core, further studies for analysing stress distribution of amalgam core with crown is recommended.

Post and Core, Pin Amalgam, Post Amalgam, finite element analysis, Second premolar