title: The Effect of Ytterbium-Doped Fiber Laser with Different Parameters on Physical Properties of Zirconia Surface.
abstract: OBJECTIVE
  Laser irradiation is an alternative surface treatment method for roughening zirconia surfaces. The aim of this study was to evaluate the effects of ytterbium-doped fiber laser (YbPL) on zirconia.
  
  
  BACKGROUND
  Zirconia surfaces are resistant to many surface treatment methods, but surface roughness is crucial for adhesion of veneering materials and cements to zirconia.
  
  
  METHODS
  The zirconia discs were prepared and divided into four groups according to the power of the laser irradiation (5, 12, 17, and 20 W). These groups were divided into five subgroups according to the frequency (25, 40, 60, 80, and 100 kHz). Surface roughness values were measured with a noncontact profilometer, and the mean Ra values were calculated. Wettability was measured with a goniometer. The surface morphology was observed with a scanning electron microscope (SEM). The changes in the surface crystalline structure were analyzed with X-ray diffractometry.
  
  
  RESULTS
  Ra values of all groups were higher than the control group. The highest surface roughness value was at 20 W and 100 kHz. Best wettability characteristic was observed at 5 W and 60 kHz. The correlations between Ra and wettability were low but significant. SEM examination of 5 W with different frequencies showed no microcracks, however, melted areas were observed. Remaining groups had microcracks and melted layers. A significantly lower T/M-phase transformation was observed in some groups.
  
  
  CONCLUSIONS
  YbPL irradiation was effective at roughening the zirconia surface. Although laser treatment affected zirconia surfaces and provided surface roughness, the power and frequency should be adjusted to achieve optimum results.
authors.affiliation: 1 Department of Prosthodontics, Faculty of Dentistry, Afyon Kocatepe University , Afyonkarahisar, Turkey .
authors.forename: Server
authors.initials: S
authors.lastname: Mutluay Unal
authors.affiliation: 1 Department of Prosthodontics, Faculty of Dentistry, Afyon Kocatepe University , Afyonkarahisar, Turkey .
authors.forename: Serhat Emre
authors.initials: SE
authors.lastname: Ozkir
authors.affiliation: 2 Department of Prosthodontics, Faculty of Dentistry, Dicle University , Diyarbakır, Turkey .
authors.forename: Zelal
authors.initials: Z
authors.lastname: Seyfioglu Polat
authors.affiliation: 2 Department of Prosthodontics, Faculty of Dentistry, Dicle University , Diyarbakır, Turkey .
authors.forename: Sedat
authors.initials: S
authors.lastname: Guven
authors.affiliation: 1 Department of Prosthodontics, Faculty of Dentistry, Afyon Kocatepe University , Afyonkarahisar, Turkey .
authors.forename: Hilal
authors.initials: H
authors.lastname: Asutay
mesh_terms: D007834:Lasers; D013499:Surface Properties / Q000528:radiation effects; D015018:Ytterbium; D015040:Zirconium / Q000528:radiation effects*
chemical_list: D015040:Zirconium; D015018:Ytterbium; C028541:zirconium oxide
keywords: YbPL; laser; surface roughness; wettability; zirconia