title: Fracture Resistance of Monolithic High Translucency Zirconia Implant-Supported Crowns.
abstract: OBJECTIVE
  To evaluate the resistance to axial forces of screw-retained monolithic high translucency zirconia (mHTZr) crowns compared with high translucency zirconia + feldspathic ceramic (HTZrC) crowns, low translucency zirconia + feldspathic ceramic (LTZrC) crowns, and metal-ceramic (MC) crowns, and also to observe the different fracture patterns between all groups.
  
  
  METHODS
  Twenty-four crowns were fabricated (6 of each group) and loaded until failure, using a testing machine with a 5.0-kN load cell.
  
  
  RESULTS
  Mean fracture results varied between 1092.7 N (LTZrC group) and 3439.7 N (mHTZr group). No statistically significant differences were found between the HTZrC, LTZrC, and MC groups. However, statistically significant differences (P < 0.05) were found between mHTZr and the other 3 groups. In the MC group, only chipping of the ceramic veneering occurred. In the mHTZr group, when fracturing occurred, it was of the whole structure. Finally, the LTZrC and HTZrC groups suffered both chipping and core fractures.
  
  
  CONCLUSIONS
  High translucency monolithic zirconia implant-supported crowns proved to be the toughest group studied when an axial force was applied. Fracture patterns varied between different materials, chipping being the most common occurrence.
authors.affiliation: *Assistant Professor, Department of Oral Stomatology I, Faculty of Medicine and Dentistry, Univ País Vasco-UPV-EHU, Leioa, Spain. †Graduate student, Master of Oral Implantologist, Department of Stomatology I, University of the Basque Country, Leioa, Spain. ‡Professor and Chair, Department of Prosthodontics and Occlusion, Faculty of Dentistry, Oviedo University, Oviedo, Spain. §Professor of Oral Implantology, Department of Oral Stomatology I, Faculty of Medicine and Dentistry, Univ País Vasco-UPV-EHU, Leioa, Spain. ¶Assistant Professor, Department of Graphics Design and Engineering Projects, University of the Basque Country UPV/EHU, Bilbao, Spain. ‖Assistant Professor, Department of Surgery and Medical Specialties, University of Oviedo, Spain. #Postgraduate Student, Department of Nuclear Engineering, UPV-EHU, University of the Basque Country, Leioa, Spain.
authors.forename: Aritza
authors.initials: A
authors.lastname: Brizuela-Velasco
authors.forename: Markel
authors.initials: M
authors.lastname: Diéguez-Pereira
authors.forename: Ángel
authors.initials: Á
authors.lastname: Álvarez-Arenal
authors.forename: David
authors.initials: D
authors.lastname: Chávarri-Prado
authors.forename: Eneko
authors.initials: E
authors.lastname: Solaberrieta
authors.forename: Felipe J
authors.initials: FJ
authors.lastname: Fernández-González
authors.forename: Yelko
authors.initials: Y
authors.lastname: Chento-Valiente
authors.forename: Gorka
authors.initials: G
authors.lastname: Santamaría-Arrieta
mesh_terms: D002516:Ceramics; D003442:Crowns / Q000592:standards; D019094:Dental Prosthesis, Implant-Supported / Q000009:adverse effects / Q000592:standards; D019232:Dental Restoration Failure; D003799:Dental Stress Analysis; D006801:Humans; D015040:Zirconium
chemical_list: D015040:Zirconium; C028541:zirconium oxide