title: Influence of four systems for dental bleaching on the bond strength of orthodontic brackets.
abstract: OBJECTIVE
  To compare the influence of four systems for dental bleaching on the shear bond strength (SBS) of orthodontic brackets.
  
  
  METHODS
  One-hundred and fifty freshly extracted bovine teeth were randomly divided into five groups. In group I the teeth were untreated (control). In the remaining groups the teeth were bleached, as follows: group II: 38% hydrogen peroxide; group III: 10% carbamide peroxide; group IV: resin-based coating material (RBCM), Beauty Coat; and group V: RBCM, White Coat. In all groups the enamel was conditioned with a self-etching primer and brackets were bonded with composite resin. Samples were stored (37°C, 24 hours), tested, and statistically analyzed, with significance predetermined at P ≤ .05. The adhesive remnant index (ARI) was also evaluated and analyzed.
  
  
  RESULTS
  The SBS of group V (22.49 ± 5.34 MPa) was significantly higher than that of all other groups (I: 17.1 ± 5.11 MPa; II: 14.72 ± 5.42 MPa; III: 12.04 ± 5.29 MPa; and IV: 18.23 ± 5.58 MPa). In contrast, the SBS of group III was significantly lower than that of all groups (except group II). Significant differences in the ARI scores were present between groups.
  
  
  CONCLUSIONS
  The use of RBCM for dental bleaching before bonding orthodontic brackets did not reduce the SBS. In contrast, hydrogen and carbamide peroxides negatively affected the SBS. The SBS yielded after bleaching with carbamide peroxide was significantly lower.
authors.affiliation: Department of Orthodontics, Autonomous University State of Mexico, Toluca, Mexico. rogelio_scougall@hotmail.com
authors.forename: Rogelio J
authors.initials: RJ
authors.lastname: Scougall-Vilchis
authors.forename: Blanca Silvia
authors.initials: BS
authors.lastname: Gonzalez-Lopez
authors.forename: Rosalia
authors.initials: R
authors.lastname: Contreras-Bulnes
authors.forename: Laura Emma
authors.initials: LE
authors.lastname: Rodriguez-Vilchis
authors.forename: Michelle Wendoline
authors.initials: MW
authors.lastname: Garcia-Niño de Rivera
authors.forename: Toshio
authors.initials: T
authors.lastname: Kubodera-Ito
mesh_terms: D000818:Animals; D000077463:Carbamide Peroxide; D002417:Cattle; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003799:Dental Stress Analysis; D003801:Dental Veneers; D006861:Hydrogen Peroxide / Q000737:chemistry; D016910:Orthodontic Brackets; D010545:Peroxides / Q000737:chemistry; D011897:Random Allocation; D019279:Resin Cements; D033081:Shear Strength; D014073:Tooth Bleaching / Q000379:methods*; D058205:Tooth Bleaching Agents / Q000737:chemistry*; D014508:Urea / Q000031:analogs & derivatives / Q000737:chemistry
chemical_list: D003188:Composite Resins; D010545:Peroxides; D019279:Resin Cements; D058205:Tooth Bleaching Agents; C501421:White Coat tooth coating material; D000077463:Carbamide Peroxide; D014508:Urea; D006861:Hydrogen Peroxide