title: Synergistic effects of sodium  ascorbate and acetone to restore compromised bond strength  after enamel bleaching.
abstract: OBJECTIVE
  To evaluate the effect of a new experimental solution containing sodium ascorbate (SA) and acetone on reversing compromised bonding to enamel immediately after bleaching.
  
  
  METHODS
  The buccal surface of intact, extracted human premolars (n = 60) was bleached. The teeth were then randomly assigned to 6  groups according to the type of pretreatment applied prior to adhesive procedures: 10% SA in acetone-water solution applied for 1 and 5 min (groups 1 and 2, respectively); aqueous solution of 10% SA applied for 10 min (group 3); 100% acetone applied for 10 min (group 4); no pretreatment (negative control; group 5). An additional group (positive control; group 6) comprised unbleached teeth (n = 12). Two composite microcylinders were bonded on each specimen for evaluation of microshear bond strength (MBS) and failure modes. Data were analyzed using the one-way ANOVA and Tukey's post-hoc and chi-square tests at P = 0.05.
  
  
  RESULTS
  Groups 1 and 2 yielded similar MBS values to groups 4 and 6 (positive control). The mean MBS of groups 3 and 5 (negative control) were similar, and significantly lower than that of the positive control group.
  
  
  CONCLUSIONS
  The application of 10% SA in an acetone-water solution prior to bonding procedures can restore compromised enamel bond strength to its unbleached state within a clinically acceptable time of 1 min.
authors.forename: Alireza
authors.initials: A
authors.lastname: Boruziniat
authors.forename: Safa
authors.initials: S
authors.lastname: Manafi
authors.forename: Zafer C
authors.initials: ZC
authors.lastname: Cehreli
mesh_terms: D000096:Acetone / Q000494:pharmacology*; D001205:Ascorbic Acid / Q000494:pharmacology*; D003743:Dental Enamel / Q000187:drug effects*; D004357:Drug Synergism; D006801:Humans; D014073:Tooth Bleaching / Q000379:methods*
chemical_list: D000096:Acetone; D001205:Ascorbic Acid