title: A 3-dimensional finite element analysis of the restoration of the maxillary canine with a complex zirconia post system.
abstract: BACKGROUND
  Zirconia posts exhibit high strength and toughness, but reliable bonding with the resin core is difficult to attain. The use of a ferrule has been found to improve stress distribution in the root of endodontically treated teeth.
  
  
  OBJECTIVE
  The purpose of this finite element analysis study was to measure the stress distribution in the post-core system and root structure of a maxillary canine.
  
  
  METHODS
  A right maxillary canine was embedded and subjected to a micro-computed tomography scan. Three-dimensional dynamic scan data were then transformed, and a finite element model of 4 dentin ferrule heights was designed with zirconia posts and heat-pressed glass ceramics for a complete crown restoration. Von Mises stresses were determined by applying a 300 N static load to the middle of the lingual surface of the crown.
  
  
  RESULTS
  When the ferrule height increased from 0 to 3 mm, the maximum von Mises stress of the zirconia post decreased from 196 to 149 MPa, and that on the zirconia post-dentin interface decreased from 174 to 132 MPa. The maximum von Mises stress decreased from 39.8 to 32.5 MPa in the apical root and from 59.5 to 49.9 MPa in the mid-root when the ferrule height increased from 0 to 3 mm.
  
  
  CONCLUSIONS
  Increased ferrule height is associated with reduced von Mises stress in the zirconia post and the post-dentin interface, with an apparent shift of von Mises stress to the root cervical area from the mid-root and the apex.
authors.affiliation: Lecturer, Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou, China.
authors.forename: Dong
authors.initials: D
authors.lastname: Chen
authors.affiliation: Lecturer, Department of Ultrasound, Guangzhou Women and Children's Medical Center, Guangzhou, China.
authors.forename: Na
authors.initials: N
authors.lastname: Wang
authors.affiliation: Lecturer, Department of Stomatology, Wuxi No. 2 People's Hospital, Wuxi, China.
authors.forename: Ya
authors.initials: Y
authors.lastname: Gao
authors.affiliation: Professor, Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou, China. Electronic address: shaolongquan@smu.edu.cn.
authors.forename: Longquan
authors.initials: L
authors.lastname: Shao
authors.affiliation: Professor, Department of Stomatology, People's Liberation Army General Hospital, Beijing, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Deng
mesh_terms: D002102:Cadaver; D002516:Ceramics / Q000737:chemistry; D003198:Computer Simulation; D003442:Crowns; D003481:Cuspid / Q000473:pathology*; D003764:Dental Materials / Q000737:chemistry*; D017267:Dental Prosthesis Design; D003804:Dentin / Q000473:pathology; D020342:Finite Element Analysis; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008422:Materials Testing; D008437:Maxilla; D008954:Models, Biological; D011176:Post and Core Technique / Q000295:instrumentation*; D013314:Stress, Mechanical; D019227:Tooth Apex / Q000473:pathology; D019237:Tooth Cervix / Q000473:pathology; D014092:Tooth Root / Q000473:pathology; D055114:X-Ray Microtomography / Q000379:methods; D015040:Zirconium / Q000737:chemistry*
chemical_list: D003764:Dental Materials; C023506:Glass ceramics; D015040:Zirconium; C028541:zirconium oxide