title: Load to failure of different zirconia abutments for an internal hexagon implant.
abstract: BACKGROUND
  Various zirconia abutment designs are available to restore implant systems. Fracture resistance is one of the criteria involved in selecting among these options.
  
  
  OBJECTIVE
  The purpose of this in vitro study was to measure and compare load to failure for 5 zirconia abutments for an internally hexagon implant.
  
  
  METHODS
  Five 4.1×11.5-mm Zimmer tapered screw-vent implants were individually secured in a loading apparatus, and 3 specimens of each of the 5 different abutments (Zimmer Contour with a Ti ring, anatomic-contour Atlantis-Zr, anatomic-contour Inclusive-Zr, anatomic-contour Astra Tech ZirDesign, Legacy Straight Contoured abutment with Ti core) (N=15) were loaded at a 30-degree angle until the implant abutment complex failed. Data for load to failure were compared with analysis of variance and a Tukey-Kramer post hoc test (α=.05).
  
  
  RESULTS
  The custom anatomic-contour abutment (Inclusive) showed the lowest load to fracture, and the stock anatomic-contour (AstraTech ZirDesign) the second lowest load to fracture. These were significantly lower than all other abutments (P<.05). The highest overall fracture strength was of a zirconia abutment with a titanium core-hexagon (Legacy Straight Contoured), which was significantly greater than all other abutments (P<.05). Anatomic-contour zirconia abutments fractured at an average of 275 N compared with the average fracture load of 842 N for zirconia abutments with titanium component (P<.05).
  
  
  CONCLUSIONS
  The stock zirconia abutment with a titanium ring and the zirconia abutment with a titanium core-hexagon (Legacy Straight Contoured) had significantly greater fracture resistance than that of any of the 1-piece anatomic-contour zirconia abutments tested.
authors.affiliation: Associate Professor, Division of Restorative and Prosthetic Dentistry, The Ohio State University College of Dentistry, Columbus, Ohio. Electronic address: yilmaz.16@osu.edu.
authors.forename: Burak
authors.initials: B
authors.lastname: Yilmaz
authors.affiliation: Private practice, Columbus, Ohio.
authors.forename: Louai G
authors.initials: LG
authors.lastname: Salaita
authors.affiliation: Research Scientist, Department of Mechanical and Aerospace Engineering, The Ohio State University College of Engineering, Columbus, Ohio.
authors.forename: Jeremy D
authors.initials: JD
authors.lastname: Seidt
authors.affiliation: Professor, Division of Restorative and Prosthetic Dentistry, The Ohio State University, College of Dentistry, Columbus, Ohio.
authors.forename: Edwin A
authors.initials: EA
authors.lastname: McGlumphy
authors.affiliation: Professor, Division of Restorative and Prosthetic Dentistry, The Ohio State University, College of Dentistry, Columbus, Ohio.
authors.forename: Nancy L
authors.initials: NL
authors.lastname: Clelland
mesh_terms: D017076:Computer-Aided Design; D000044:Dental Abutments; D059605:Dental Implant-Abutment Design; D003764:Dental Materials / Q000737:chemistry*; D019232:Dental Restoration Failure; D003799:Dental Stress Analysis; D006801:Humans; D008422:Materials Testing; D013314:Stress, Mechanical; D014025:Titanium / Q000737:chemistry*; D015040:Zirconium / Q000737:chemistry*
chemical_list: D003764:Dental Materials; D015040:Zirconium; D014025:Titanium; C028541:zirconium oxide