title: Durability of bleaching results achieved with 15% carbamide peroxide and 38% hydrogen peroxide in vitro.
abstract: The aim of this study was to assess the durability of bleaching results achieved with (1) 15% carbamide peroxide home bleaching and (2) 38% hydrogen peroxide in-office bleaching. A total of 231 extracted anterior teeth were randomly divided into three groups (n = 77 in each group) with comparable mean baseline L*-values (68.24 ± 0.8): a non-bleached control group A, a 15% carbamide peroxide group B (5 bleaching intervals of 8 hours), and a 38% hydrogen peroxide group C (3 intervals of 15 minutes). Durability of bleaching was assessed by comparing CIE-L*a*b* data after intervals of 2, 4, 12, and 26 weeks from baseline. Both bleaching regimes initially produced a highly significant increase in lightness parameter L*, with no significant difference between the respective bleaching regimes (B: 68.23 / 72.48; C: 68.32 / 73.25). Six months after starting the trial, L*-values for group B yielded no significant differences compared to baseline (69.55), whereas L*-values for group C were still significantly raised (69.91), despite a highly significant decrease when compared to initial bleaching results. In both treatment groups, there was a lasting response to bleaching in terms of CIE-a* and -b* value decreases. Results for both home- and in-practice regimes were found to be similar for about 12 weeks. However, in-office results were longer lasting, despite the shorter treatment intervals. Summarized bleaching effects, in terms of delta E values, revealed no significant differences between treatment groups and the control group after 6 months, indicating an abatement of the bleaching results achieved.
authors.affiliation: University Medical Center, Gottingen, Germany. mknoesel@yahoo.de
authors.forename: Michael
authors.initials: M
authors.lastname: Knösel
authors.forename: Monika
authors.initials: M
authors.lastname: Reus
authors.forename: Albert
authors.initials: A
authors.lastname: Rosenberger
authors.forename: Thomas
authors.initials: T
authors.lastname: Attin
authors.forename: Dirk
authors.initials: D
authors.lastname: Ziebolz
mesh_terms: D000704:Analysis of Variance; D000077463:Carbamide Peroxide; D003742:Dental Devices, Home Care; D006801:Humans; D006861:Hydrogen Peroxide / Q000737:chemistry / Q000627:therapeutic use*; D010545:Peroxides / Q000737:chemistry / Q000627:therapeutic use*; D023861:Photography, Dental; D016037:Single-Blind Method; D013997:Time Factors; D014073:Tooth Bleaching / Q000379:methods*; D058205:Tooth Bleaching Agents / Q000737:chemistry / Q000627:therapeutic use*; D016896:Treatment Outcome; D014508:Urea / Q000031:analogs & derivatives* / Q000737:chemistry / Q000627:therapeutic use
chemical_list: D010545:Peroxides; D058205:Tooth Bleaching Agents; D000077463:Carbamide Peroxide; D014508:Urea; D006861:Hydrogen Peroxide