title: [Three  dimensional Finite Element Analysis of the Effects of Posts and Cores with Different Angles]
abstract: OBJECTIVE:The test is an analogue of the conditions that cast post and core can be made with different angles to get the core incline lingually or facially in clinic, so that the arrangement of the anterior teeth may be improved.METHODS:Analyse the stress distribution and concentration in the dentin of posts and cores with different angles by Ansys three  dimensional finite element stress analysis method.RESULTS:The stress in root was positively related to the angles between the load and the axis of the tooth, the stress distributoin in dentin was related to the direction of the core but not related to the angles. The closer the distance from the load to cemento  enamel junction,the greater the effect of the load on the stress in dentin.CONCLUSION:When the cast post and core with angle was used to rectify the facially malpositional maxillary anterior teeth, the core should not be inclined lingually excessively. It is important to assure the thickness of the facial and lingual canal wall during tooth preparing and to adjust the occlusion so that the root fracture can be avoided.
authors.affiliation: Department of Prosthodontics, the Affiliated 9th People's Hospital of Shanghai Second Medical University. Shanghai 200011,China.
authors.forename: B W
authors.initials: BW
authors.lastname: Zhang
authors.forename: H J
authors.initials: HJ
authors.lastname: Pan
authors.forename: S B
authors.initials: SB
authors.lastname: Ye