Abstract: Objectives: To assess the stress of post and cores with different sizes and materials in restoring anterior teeth with flared canals. Methods: Nine 3D models of maxillary first incisors with flared canals restored by two post groups were generated. Group A is restored with preformed posts. Group B is restored with anatomic posts. The model of a quartz fiber post combined with just one auxiliary post is the control one for group A and B. Each model was loaded occlusal force of 100 N on the palatal surface of the crowns at 135 degree angles to the long axis of the tooth. The stresses in the dentin, in the cement, in the post and in the core were analyzed. Results: There was an inverse correlation between the stress of dentin and the volume of the posts. It was failed to establish a correlation between the stress of dentin and the modulus of elasticity of the post and core. The stress of the post and core had an inverse correlation with its modulus of elasticity. Conclusion: It is suggested to restore the tooth with flared canals by larger size posts, such as anatomic one. The post and core are more easy to drop off with larger modulus of elasticity.

Key words: Post and core, Teeth with flared canals, Three dimensional finite element analysis