title: The influence of Er:YAG laser conditioning versus self-etching adhesives with acid etching on the shear bond strength of orthodontic brackets.
abstract: OBJECTIVE
  The aim of this study was to compare the shear bond strength (SBS) of orthodontic brackets after acid etching, laser ablation, self-etching primer application, and combined treatments.
  
  
  METHODS
  One hundred defect-free premolars were randomly assigned to five groups. The teeth received the following treatments: group 1: phosphoric acid + Transbond XT primer; group 2: Transbond Plus Self-Etching Primer (TPSEP); group 3: Er:YAG laser ablation + Transbond XT primer; group 4: Er:YAG laser ablation + phosphoric acid + Transbond XT primer; and group 5: Er:YAG laser ablation + TPSEP. Transbond XT Adhesive Paste was used in all groups for bracket bonding. Samples were stored in deionized water at 37 degrees C for 24 h. The shear debonding test was performed at a crosshead speed of 5 mm/min. Failed brackets were examined by a stereomicroscope at 16 x magnification to determine the bond failure interface using a modified adhesive remnant index (ARI). SBS values were compared using one-way analysis of variance (ANOVA). The Kruskal-Wallis test was used for ARI scores and pairwise comparisons were done using the Mann-Whitney U test with Bonferroni correction.
  
  
  RESULTS
  Mean SBS values (MPa) and standard deviations for the groups were: group 1, 13.18 +/- 3.45; group 2, 13.52 +/- 4.38; group 3, 10.33 +/- 4.74; group 4, 13.00 +/- 3.47; and group 5, 12.46 +/- 6.31. No significant differences were observed in the SBS of all the groups evaluated, but there was a significant difference in ARI scores, with group 3 showing higher ARI scores than groups 1 and 4.
  
  
  CONCLUSIONS
  Er:YAG laser ablation and self-etching primer application showed similar SBS values as conventional acidetching for bonding brackets.
authors.affiliation: Department of Orthodontics, Faculty of Dentistry, Baskent University, Ankara, Turkey.
authors.forename: Aylin
authors.initials: A
authors.lastname: Gokcelik
authors.forename: Yonca
authors.initials: Y
authors.lastname: Ozel
authors.forename: Emre
authors.initials: E
authors.lastname: Ozel
authors.forename: Neslihan
authors.initials: N
authors.lastname: Arhun
authors.forename: Nuray
authors.initials: N
authors.lastname: Attar
authors.forename: Sonmez
authors.initials: S
authors.lastname: Firatli
authors.forename: Erhan
authors.initials: E
authors.lastname: Firatli
mesh_terms: D000134:Acid Etching, Dental; D001840:Dental Bonding; D006801:Humans; D053685:Laser Therapy; D016910:Orthodontic Brackets; D019279:Resin Cements / Q000528:radiation effects*; D033081:Shear Strength
chemical_list: D019279:Resin Cements; C429625:Transbond Plus Self-Etching Primer