title: Assessing the effects of hydrogen peroxide bleaching agent on the shear bond strength of orthodontic brackets.
abstract: BACKGROUND
  Tooth bleaching is, today, one of the most widespread cosmetic treatments in dental practice,  so it is important to determine whether it can interfere with orthodontic bonding or not.
  
  
  OBJECTIVE
  The aim of this study was to assess the in vitro effects of 35% hydrogen peroxide bleaching agent on the shear bond strength of orthodontic brackets.
  
  
  METHODS
  Forty-five upper bicuspids were divided into three groups (n = 15). In the control Group (C), the brackets were bonded without previous bleaching treatment. Group 1 (G1) was treated with 35% hydrogen peroxide bleaching agent 24 h before bracket bonding. Group 2 was also bleached, and the brackets were bonded after 30 days. The shear bond strength of the brackets was measured using an EMIC machine, and the results were analyzed by ANOVA.
  
  
  RESULTS
  There were no statistically significant differences between the three groups (P > 0.05), with Group C showing a mean bond strength of 9.72 ± 2.63 MPa, G1 of 8.09 ± 2.63 MPa, and G2 of 11.15 ± 4.42 MPa.
  
  
  CONCLUSIONS
  It was possible to conclude that 35% hydrogen peroxide bleaching agent does not affect the shear strength of orthodontic brackets bonded 24 h and 30 days after bleaching.
authors.affiliation: Department of Orthodontics, Latin American Institute of Dental Research and Education, Curitiba, Paraná, Brazil.
authors.forename: Augusto Ricardo
authors.initials: AR
authors.lastname: Andrighetto
authors.affiliation: Department of Orthodontics, Latin American Institute of Dental Research and Education, Curitiba, Paraná, Brazil.
authors.forename: Eduardo Henrique
authors.initials: EH
authors.lastname: de Leão Withers
authors.affiliation: Department of Orthodontics, Latin American Institute of Dental Research and Education, Curitiba, Paraná, Brazil.
authors.forename: Karlos Giovani
authors.initials: KG
authors.lastname: Grando
authors.affiliation: Department of Orthodontics, University of São Paulo State (UNESP), Araraquara, São Paulo, Brazil.
authors.forename: Aldrieli Regina
authors.initials: AR
authors.lastname: Ambrosio
authors.affiliation: Department of Orthodontics, Latin American Institute of Dental Research and Education, Curitiba, Paraná, Brazil.
authors.forename: Roberto Hideo
authors.initials: RH
authors.lastname: Shimizu
authors.affiliation: Department of Orthodontics, Latin American Institute of Dental Research and Education, Curitiba, Paraná, Brazil.
authors.forename: Ana Cláudia
authors.initials: AC
authors.lastname: Melo
mesh_terms: D001641:Bicuspid; D057886:Bleaching Agents / Q000737:chemistry*; D001840:Dental Bonding / Q000379:methods*; D003799:Dental Stress Analysis; D006801:Humans; D006861:Hydrogen Peroxide / Q000737:chemistry*; D066298:In Vitro Techniques; D008422:Materials Testing; D016910:Orthodontic Brackets; D033081:Shear Strength; D014073:Tooth Bleaching
chemical_list: D057886:Bleaching Agents; D006861:Hydrogen Peroxide