title: Fatigue behavior of Y-TZP ceramic after surface treatments.
abstract: OBJECTIVE
  The aim of this study was to evaluate the effect of three surface treatments on the biaxial flexural strength before and after mechanical cycling, and fatigue limit of a Y-TZP ceramic.
  
  
  METHODS
  Disc-shaped specimens were produced and three surface conditions were tested: CT (as-sintered, untreated), GL (thin layer of porcelain glaze), and AA (air abrasion with 30µm silica particles). Profilometric and phase transformation analyses were performed. Disks were submitted to biaxial flexural strength (BFS) before and after mechanical cycling (100N, 2×10(6) cycles) and staircase approach (n=20). The flexural fatigue limits (FFLs) were obtained at 10(2), 10(3), 10(4) and 10(5) cycles.
  
  
  RESULTS
  Tetragonal to monoclinic transformation was only observed for AA group (9.46% of monoclinic phase). Glazed group presented the highest Ra values. Flexural strength was higher for AA group; CT and GL groups were similar. The reliability was similar between groups. The mechanical cycling at 100N did not affected flexural strength. FFLs were higher for AA group, and the three surface treatments presented decrease in strength according to the increase in number o cycles.
authors.affiliation: Department of Dental Materials and Prosthesis, Dentistry School, Sao Paulo State University, Av. Eng Franscisco José Longo, 777, Sao Jose dos Campos, Brazil. Electronic address: marinamaral_85@yahoo.com.br.
authors.forename: Marina
authors.initials: M
authors.lastname: Amaral
authors.affiliation: Department of Dental Materials, Dentistry School, Sao Paulo University, Av. Prof Lineu Prestes, 2227 Sao Paulo, Brazil. Electronic address: paulofc@usp.br.
authors.forename: Paulo Francisco
authors.initials: PF
authors.lastname: Cesar
authors.affiliation: Department of Dental Materials and Prosthesis, Dentistry School, Sao Paulo State University, Av. Eng Franscisco José Longo, 777, Sao Jose dos Campos, Brazil. Electronic address: mmbottino@uol.com.br.
authors.forename: Marco Antonio
authors.initials: MA
authors.lastname: Bottino
authors.affiliation: Head of the Laboratory for Biomaterials Research, Dental Clinic 1 - Operative Dentistry and Periodontology, University of Erlangen-Nuernberg, Glueckstrasse, 11, Erlangen, Germany. Electronic address: ulrich.lohbauer@fau.de.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Lohbauer
authors.affiliation: Department of Restorative Dentistry, Dentistry School, Prosthodontic Unit, Federal University of Santa Maria, Rua Marechal Floriano Peixoto, 1184, 97015-372 Santa Maria, Rio Grande do Sul, Brazil. Electronic address: lfvalandro@hotmail.com.
authors.forename: Luiz Felipe
authors.initials: LF
authors.lastname: Valandro
mesh_terms: D002516:Ceramics; D008422:Materials Testing; D013314:Stress, Mechanical; D013499:Surface Properties; D015019:Yttrium; D015040:Zirconium
chemical_list: C499362:yttria stabilized tetragonal zirconia; D015019:Yttrium; D015040:Zirconium
keywords: Fatigue; Strength; Surface treatments; Weibul analysis; Zirconia ceramic