title: In vitro fatigue and fracture strength testing of one-piece zirconia implant abutments and zirconia implant abutments connected to titanium cores.
abstract: OBJECTIVE
  The purpose of this study was to determine the fatigue and fracture strength of zirconia implant abutments connected to titanium cores (ZrTi) and one-piece zirconia implant abutments (Zr).
  
  
  METHODS
  Thirty-two implants were secured into epoxy resin blocks and connected with abutments. Eight specimens of each group (Zr with a diameter of 3.75 mm [Zr3.75] or 5.5 mm [Zr5.5] and ZrTi with a diameter of 3.75 mm [ZrTi3.75] or 5.5 mm [ZrTi5.5]) were thermally cycled from 5°C to 55°C and loaded with 100,000 cycles at 120 N at 30 degrees off-axis. All specimens were then tested for fracture resistance using a compressive load at 30 degrees off-axis.
  
  
  RESULTS
  Abutment fracture or screw loosening was not observed during thermal cycling and cyclic loading. The median fracture resistance values and standard deviations were 526 N (± 32 N) for group Zr3.75, 1,241 N (± 269 N) for group ZrTi3.75, 1,894 N (± 137 N) for group Zr5.5, and 2,225 N (± 63 N) for group ZrTi5.5. Statistically significant differences in fracture strength were found between Zr and ZrTi for each implant diameter.
  
  
  CONCLUSIONS
  Zirconia implant abutments connected to titanium cores showed higher fracture strength compared to one-piece zirconia abutments. Hence, they might be preferable for clinical use.
authors.affiliation: University of Munich, Department of Prosthodontics, Munich, Germany. praxis@m-stimmelmayr.de
authors.forename: Michael
authors.initials: M
authors.lastname: Stimmelmayr
authors.forename: Stefanie
authors.initials: S
authors.lastname: Sagerer
authors.forename: Kurt
authors.initials: K
authors.lastname: Erdelt
authors.forename: Florian
authors.initials: F
authors.lastname: Beuer
mesh_terms: D000044:Dental Abutments; D059605:Dental Implant-Abutment Design; D019232:Dental Restoration Failure; D003799:Dental Stress Analysis / Q000379:methods*; D012117:Resins, Synthetic; D013314:Stress, Mechanical; D014025:Titanium; D015040:Zirconium
chemical_list: D012117:Resins, Synthetic; D015040:Zirconium; D014025:Titanium; C028541:zirconium oxide