Effect of post material on stress of maxillary central incisor with medium tooth defect

Objective To investigate the influence of the stress statement on residual dentin with two different post-core on maxillary central incisor with 50％ of tooth defect (gingival place one-third of the crown defect and integrity).Methods Four endodontically treated tooth with 50％ of tooth defect were established by the computer:glass fiber post,resin core and porcelain fused to metal crown (PFMC) as restoration or restored by metal post-core and PFMC separately when gingival place one-third of the crown defect and integrity.Clinical load was simulated.Von Mises and the maximum stress were chosen.The stress peak value and stress distribution on residual dentin were investigated with different models.Results Each model showed the same stress distribution on the surface of dentin,the stresses showed significant stress concentration at the lingual cervical margin and at the cervical one-third of the tooth.From the section plane,stress distribution showed homogeneous in the glass fiber restored models,while in metal restored models,stress distribution changed significantly but stress peak was decreasing on the surface of dentine.Conclusions Comparing different post and core materials,fiber post is recommended if enough tooth structure presents at gingival place; and metal post is used if only limited tooth structure presents. Key words: Maxillary central incisor;  Post and core;  Finite element analysis