title: [Three dimensional finite element analysis on stress distribution in dentin of the maxillary central incisor restored with different shapes and materials of post].
abstract: OBJECTIVE
  To investigate the stress distribution in dentin of the maxillary central incisor restored with post-core which is related to different shapes and materials.
  
  
  METHODS
  CT scan, digital-image processing and Unigraphics (UG) software were applied to construct the three-dimensional finite element models of maxillary central incisor restored with cone or column post-core. Based on this model, stress distribution of Von Mises in dentin with three different materials(polyethylene fiber resin, carbon fiber and zirconia) were analyzed respectively. Static loading(100N) was used on the lingual boundary line between upper-one-third and middle-one-third of maxillary central incisor, the direction of the loading was 45 degrees to the tooth long axis.
  
  
  RESULTS
  In posts made of zirconia and restored with column post, the stress distribution in dentin was higher than with cone post (P<0.05). In posts made of polyethylene fiber resin or carbon fiber, there was no significant difference between the two post shapes (P>0.05). The elastic modulus of post-core materials affected the stress distribution, and the higher the elastic modulus was, the higher the stress concentrated.
  
  
  CONCLUSIONS
  Cone post excels column post in higher elastic modulus materials. Using the lower elastic modulus materials possibly can avail to the stress distribution and prevent the root breakage. During the root canal preparation, the dentin around the root neck should be conserved as more as possible, especially the dentin in the labial side.
authors.affiliation: Dept. of Prosthodontics, School of Stomatology, Tongji University, Shanghai 200072, China.
authors.forename: Xuying
authors.initials: X
authors.lastname: Zhang
authors.forename: Jing
authors.initials: J
authors.lastname: Sun
authors.forename: Jun
authors.initials: J
authors.lastname: Lu
mesh_terms: D003188:Composite Resins; D003198:Computer Simulation; D003764:Dental Materials; D003804:Dentin; D055119:Elastic Modulus; D020342:Finite Element Analysis; D005898:Glass; D007180:Incisor; D008422:Materials Testing; D011176:Post and Core Technique; D014092:Tooth Root; D015040:Zirconium
chemical_list: D003188:Composite Resins; D003764:Dental Materials; D015040:Zirconium; C028541:zirconium oxide