title: Etching enamel for orthodontics with an erbium, chromium:yttrium-scandium-gallium-garnet laser system.
abstract: OBJECTIVE
  To test the shear bond strength, surface characteristics, and fracture mode of brackets that are bonded to enamel etched with an erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser operated at different power outputs: 0.5 W, 1 W, and 2 W.
  
  
  METHODS
  Human premolars that had been extracted for orthodontic purposes were used. Enamel was etched with an Er,Cr:YSGG laser system operated at one of three power outputs or with orthophosphoric acid.
  
  
  RESULTS
  The shear bond strength associated with the 0.5-W laser irradiation was significantly less than the strengths obtained with the other irradiations. Both the 1-W and 2-W laser irradiations were capable of etching enamel in the same manner. This finding was confirmed by scanning electron microscopy examination. The evaluation of adhesive-remnant-index scores demonstrated no statistically significant difference in bond failure site among the groups, except for the 0.5-W laser-etched group. Generally, more adhesive was left on the enamel surface with laser irradiation than with acid etching.
  
  
  CONCLUSIONS
  The mean shear bond strength and enamel surface etching obtained with an Er,Cr: YSGG laser (operated at 1 W or 2 W for 15 seconds) is comparable to that obtained with acid etching.
authors.affiliation: Dicle University, Orthodontics, Faculty of Dentistry, Campus, Diyarbakir, Turkey. basaran@dicle.edu.tr
authors.forename: Güvenç
authors.initials: G
authors.lastname: Basaran
authors.forename: Törün
authors.initials: T
authors.lastname: Ozer
authors.forename: Nükhet
authors.initials: N
authors.lastname: Berk
authors.forename: Orhan
authors.initials: O
authors.lastname: Hamamci
mesh_terms: D000704:Analysis of Variance; D001641:Bicuspid; D016009:Chi-Square Distribution; D002857:Chromium; D001840:Dental Bonding; D017005:Dental Debonding; D003743:Dental Enamel; D045662:Dental Etching / Q000379:methods*; D003799:Dental Stress Analysis; D004871:Erbium; D006801:Humans; D007834:Lasers; D008855:Microscopy, Electron, Scanning; D010756:Phosphoric Acids; D033081:Shear Strength; D013499:Surface Properties
chemical_list: D010756:Phosphoric Acids; D002857:Chromium; D004871:Erbium; C030242:phosphoric acid