title: Effect Of Nd:YAG laser and CO2 laser treatment on the resin bond strength to zirconia ceramic.
abstract: OBJECTIVE
  this study evaluated the effect of surface treatments (Nd:YAG laser, CO2 laser, Al203 airborne-particle abrasion, and silica-coating) on the zirconia-to-resin shear bond strength (SBS).
  
  
  METHODS
  eighty-one Lava (3M ESPE) blocks (13 x 4 x 2 mm) were embedded in acrylic resin, polished, and randomly divided into three groups, which received the following surface treatments: no abrasion, Al203 airborne-particle abrasion (50 Μm), or silica-coating (Cojet, 3M ESPE). Each group was divided into three subgroups that were treated with Nd:YAG laser, CO2 laser, or no laser irradiation. Following application of a monomer phosphate-containing primer, cylinders of resin cement (Panavia F, Kuraray) (n = 18) were built on the surface. SBS testing was carried out after 24 hours of storage in water. Surface roughness and topography (SEM) after treatments were evaluated.
  
  
  RESULTS
  according to ANOVA and Tukey test ( α = 0.05), mean SBS after Nd:YAG laser treatment ranged from 14.09 to 16.20 MPa and was statistically higher than CO2 laser (6.24 to 10.51 MPa) and no laser treatment (4.65 to 8.79 MPa). The Nd:YAG laser created more roughness on zirconia when compared to the CO2 laser and abrasion treatments. Silica-coating increased the SBS of lased and nonlased zirconia. Significant microcracks were found on specimens treated with CO2.
  
  
  CONCLUSIONS
  Nd:YAG laser pretreatment, whether associated with abrasion methods or not, created consistent roughness on the zirconia surface and significantly increased zirconia SBS to Panavia F. Silica-coating could potentially increase the SBS of lased and nonlased zirconia. Significant microcracks were found on specimens treated with the CO2 laser.
authors.affiliation: Division of Restorative Sciences, Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, California 90089-7792, USA.
authors.forename: Maria Paula Gandolfi
authors.initials: MP
authors.lastname: Paranhos
authors.forename: Luiz Henrique
authors.initials: LH
authors.lastname: Burnett
authors.forename: Pascal
authors.initials: P
authors.lastname: Magne
mesh_terms: D020906:Air Abrasion, Dental; D000704:Analysis of Variance; D020099:Coated Materials, Biocompatible; D001840:Dental Bonding; D003776:Dental Porcelain; D003799:Dental Stress Analysis; D054020:Lasers, Gas; D053844:Lasers, Solid-State; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D011897:Random Allocation; D019279:Resin Cements; D033081:Shear Strength; D012822:Silicon Dioxide; D018709:Statistics, Nonparametric; D013499:Surface Properties; D015019:Yttrium; D015040:Zirconium
chemical_list: D020099:Coated Materials, Biocompatible; D019279:Resin Cements; C499362:yttria stabilized tetragonal zirconia; D003776:Dental Porcelain; D015019:Yttrium; D012822:Silicon Dioxide; D015040:Zirconium