title: Effect of cement space on stress distribution in Y-TZP based crowns.
abstract: To evaluate the stress distribution in bi-layered Y-TZP based crowns, according to the occlusal internal spacing between coping and abutment.
  
  
  
  Twelve premolar shaped Y-TZP copings were made by a CAD/CAM system and seated on an abutment to evaluate the internal fit at the occlusal third using micro-CT images. Considering the fitting range obtained experimentally, two 3D finite element models, consisting on bone tissue, a titanium implant, a zirconia abutment, cement layer and a bi-layered Y-TZP ceramic crown were constructed based on the micro-CT images, one corresponding to the thinnest cement space and other representing the specimen with the thickest cement space obtained experimentally. A 250N axial load was applied at the center of the occlusal surface of the crown (≅0,8mm2area) and the first principal stress distribution was plotted and analyzed.
  
  
  
  The greatest maximum principal stress occurred within the veneer ceramic right below the site of loading. The thickest cement model showed higher stress concentration at the center of occlusal surface of veneer and the center of occlusal internal surface of coping.
  
  
  
  Knowledge of stress distribution in ceramic crowns with different cement thicknesses will help clinicians to properly adjust crown fit, in seeking to avoid porcelain fractures.
authors.affiliation: Department of Prosthodontics, Bauru School of Dentistry, University of São Paulo, Alameda Octávio Pinheiro Brisolla 9-75, Bauru, SP 17012-901, Brazil; Post-Graduation Program in Clinical Dentistry, Dental School, Positivo University, 5300 Pedro Viriato Parigot de Souza Rd., Curitiba, PR 81280-330, Brazil. Electronic address: caerezende@gmail.com.
authors.forename: Carlos Eduardo Edwards
authors.initials: CE
authors.lastname: Rezende
authors.affiliation: Department of Operative Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo, Alameda Octávio Pinheiro Brisolla 7-35, Bauru, SP 17012-901, Brazil. Electronic address: afborges@fob.usp.br.
authors.forename: Ana Flávia Sanches
authors.initials: AF
authors.lastname: Borges
authors.affiliation: Post-Graduation Program in Clinical Dentistry, Dental School, Positivo University, 5300 Pedro Viriato Parigot de Souza Rd., Curitiba, PR 81280-330, Brazil. Electronic address: carlacgonzaga2@gmail.com.
authors.forename: Carla Castiglia
authors.initials: CC
authors.lastname: Gonzaga
authors.affiliation: Department of Biomedical Materials Science, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS 39216-4505, USA. Electronic address: yduan@umc.edu.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Duan
authors.affiliation: Department of Prosthodontics, Bauru School of Dentistry, University of São Paulo, Alameda Octávio Pinheiro Brisolla 9-75, Bauru, SP 17012-901, Brazil. Electronic address: jrubo@fob.usp.br.
authors.forename: José Henrique
authors.initials: JH
authors.lastname: Rubo
authors.affiliation: Department of Biomedical Materials Science, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS 39216-4505, USA. Electronic address: jgriggs@umc.edu.
authors.forename: Jason Alan
authors.initials: JA
authors.lastname: Griggs
mesh_terms: D003442:Crowns; D003776:Dental Porcelain; D017267:Dental Prosthesis Design; D003799:Dental Stress Analysis; D020342:Finite Element Analysis; D006801:Humans; D013314:Stress, Mechanical; D015019:Yttrium; D015040:Zirconium
chemical_list: C499362:yttria stabilized tetragonal zirconia; D003776:Dental Porcelain; D015019:Yttrium; D015040:Zirconium
keywords: CAD–CAM; Cement thickness; Ceramic crowns; Ceramic restorative materials; Finite element analysis; Fit; Micro-CT; Zirconia