title: Veneer Ceramic to Y-TZP Bonding: Comparison of Different Surface Treatments.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the effects of various surface-treatment techniques for enhancing the bond strength between veneering ceramic and yttria-stabilized tetragonal zirconia polycrystals (Y-TZP).
  
  
  METHODS
  Pre-sintered Y-TZP specimens were divided into eight groups (n = 10) according to the surface-treatment technique used: (a) untreated (control); (b) air abrasion with aluminum oxide particles; (c) erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser irradiation at different energy intensities (1 to 6 W). All specimens were then sintered and veneered with veneering ceramic according to the manufacturer's instructions. The obtained zirconia-ceramic specimens were immersed in 37°C distilled water for 24 hours before a shear bond strength test using a universal testing device at a 1 mm/min crosshead speed. The average values were calculated. After debonding, the Y-TZP surfaces were examined under a stereomicroscope to determine their fracture pattern, and the surface topography was evaluated with scanning electron microscopy after surface treatments.
  
  
  RESULTS
  The bond strength ranged from 13.24 to 20.54 MPa. All surface treatments increased the bond strength between the veneering ceramic and Y-TZP; however, the value for the 6 W irradiation group was significantly different from the values for other groups (p ˂ 0.05).
  
  
  CONCLUSIONS
  The present study's findings showed that higher energy densities were needed for the laser irradiation to improve the bond strength between the veneering ceramic and zirconia.
  
  
  CONCLUSIONS
  Y-TZP is commonly used as a core material in fixed restorations. The bond strength between zirconia and the veneering ceramic can be affected by various surface treatments.
authors.affiliation: Department of Prosthodontics, Faculty of Dentistry, Akdeniz University, Antalya, Turkey.
authors.forename: Omer
authors.initials: O
authors.lastname: Kirmali
authors.affiliation: Department of Restorative Dentistry, Faculty of Dentistry, Cumhuriyet University, Sivas, Turkey.
authors.forename: Alper
authors.initials: A
authors.lastname: Kapdan
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Akdeniz University, Antalya, Turkey.
authors.forename: Alper
authors.initials: A
authors.lastname: Kustarci
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Akdeniz University, Antalya, Turkey.
authors.forename: Kursat
authors.initials: K
authors.lastname: Er
mesh_terms: D002516:Ceramics; D001840:Dental Bonding; D003776:Dental Porcelain; D003801:Dental Veneers; D006801:Humans; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D033081:Shear Strength; D013499:Surface Properties; D015019:Yttrium; D015040:Zirconium
chemical_list: D003776:Dental Porcelain; D015019:Yttrium; D015040:Zirconium
keywords: Er-Cr:YSGG laser; SEM; Yttria-stabilized tetragonal zirconia polycrystal (Y-TZP); dental lasers; shear bond strength; surface treatments; veneering ceramics; zirconia restorations