title: The effect of different power outputs of carbon dioxide laser on bonding between zirconia ceramic surface and resin cement.
abstract: OBJECTIVE
  The purpose of this in vitro study was to evaluate the influence of different power outputs of a carbon dioxide (CO2) laser on shear bond strength of resin cement to zirconium dioxide-based ceramic.
  
  
  METHODS
  Fifty zirconium dioxide core specimens (10 mm diameter and 2 mm thickness) were produced and they were embedded in the centers of auto-polymerizing acrylic resin blocks. Ten specimens served as control and no surface treatment was applied. Subsequently specimens were randomly divided into four groups, each containing 10 specimens for surface treatment with CO2 laser with different output power; laser treated with 2 W (Group 2 W), 3 W (Group 3 W), 4 W (Group 4 W) and finally 5 W (Group 5 W). Fifty composite resin discs were fabricated and cemented with adhesive resin cement to the specimen surfaces. A universal test machine was used for shear bond strength test at a crosshead speed 1 mm/min. Data were statistically analyzed by one-way analyses of variance (ANOVA) with Post-Hoc Tukey tests (α = 0.05).
  
  
  RESULTS
  It was found that the shear bond strength values were affected by power outputs of laser (p < 0.05). Highest shear bond strength values were obtained with group 2 W (21.0 ± 2.7). Lowest values were obtained with group 5 W (14.4 ± 1.6).
  
  
  CONCLUSIONS
  The current study revealed that there was a relationship between laser output power and shear bond strength for zirconium dioxide ceramics. However, output power of the laser and the energy level is a critical factor on micromechanical retention.
authors.affiliation: Ondokuz Mayis University, Faculty of Dentistry, Department of Prosthodontics, Samsun, Turkey. cagriural@omu.edu.tr
authors.forename: CaĞri
authors.initials: C
authors.lastname: Ural
authors.forename: Elif
authors.initials: E
authors.lastname: KalyoncuoĞlu
authors.forename: Veysel
authors.initials: V
authors.lastname: Balkaya
mesh_terms: D000704:Analysis of Variance; D002245:Carbon Dioxide / Q000737:chemistry*; D003738:Dental Cements; D007834:Lasers; D008855:Microscopy, Electron, Scanning; D015040:Zirconium / Q000737:chemistry*
chemical_list: D003738:Dental Cements; D002245:Carbon Dioxide; D015040:Zirconium; C028541:zirconium oxide