title: Stress distribution of oval and circular fiber posts in amandibular premolar: a three-dimensional finite element analysis.
abstract: OBJECTIVE
  The aim of the present study was to evaluate the effects of posts with different morphologies on stress distribution in an endodontically treated mandibular premolar by using finite element models (FEMs).
  
  
  METHODS
  A mandibular premolar was modeled using the ANSYS software program. Two models were created to represent circular and oval fiber posts in this tooth model. An oblique force of 300 N was applied at an angle of 45° to the occlusal plane and oriented toward the buccal side. von Mises stress was measured in three regions each for oval and circular fiber posts.
  
  
  RESULTS
  FEM analysis showed that the von Mises stress of the circular fiber post (426.81 MPa) was greater than that of the oval fiber post (346.34 MPa). The maximum distribution of von Mises stress was in the luting agent in both groups. Additionally, von Mises stresses accumulated in the coronal third of root dentin, close to the post space in both groups.
  
  
  CONCLUSIONS
  Oval fiber posts are preferable to circular fiber posts in oval-shaped canals given the stress distribution at the post-dentin interface.
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Erciyes University, Kayseri, Turkey.
authors.forename: Ozgur
authors.initials: O
authors.lastname: Er
authors.affiliation: Department Prosthodontics, Faculty of Dentistry, Erciyes University, Kayseri, Turkey.
authors.forename: Kerem
authors.initials: K
authors.lastname: Kilic
authors.affiliation: Department of Mechanical Engineering, Faculty of Engineering, Erciyes University, Kayseri, Turkey.
authors.forename: Emir
authors.initials: E
authors.lastname: Esim
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Erciyes University, Kayseri, Turkey.
authors.forename: Tugrul
authors.initials: T
authors.lastname: Aslan
authors.affiliation: Department Prosthodontics, Faculty of Dentistry, Erciyes University, Kayseri, Turkey.
authors.forename: Halil Ibrahim
authors.initials: HI
authors.lastname: Kilinc
authors.affiliation: Department of Mechanical Engineering, Faculty of Engineering, Erciyes University, Kayseri, Turkey.
authors.forename: Sahin
authors.initials: S
authors.lastname: Yildirim
keywords: Finite element analysis; Post and core technique