title: Reversal of reduced bond strength after bleaching.
abstract: This article investigated how the shear bond strength of a luting resin to dentin was affected by antioxidant treatment and delayed bonding after bleaching with carbamide peroxide. Using a lowspeed diamond saw, 40 flat dentin surfaces were prepared from freshly extracted human molars and divided into three bleaching groups (n = 10) and a control group (n = 10). Group 1 consisted of specimens bonded immediately after bleaching. Group 2 specimens were treated with an antioxidant agent (10% sodium ascorbate), while Group 3 specimens were immersed in artificial saliva for one week after bleaching. Specimens in Group 4 were not bleached but were immersed in artificial saliva for one week before bonding. Forty ceramic blocks were prepared and luted to teeth using a dual-curing resin cement. The specimens were thermocycled and the shear bond strength tests were performed using a universal testing machine. Fracture analysis was performed using a scanning electron microscope. While the Group 1 samples demonstrated the lowest shear bond strengths (11.9 +/- 3 MPa) (p < 0.05), no significant differences were found among samples in Group 2 (26.3 +/- 7.1 MPa), Group 3 (20.7 +/- 6.5 MPa), and Group 4 (22.1 +/- 2.5 MPa) (p = 0.05).
authors.affiliation: Department of Prosthodontics, School of Dentistry, University of Ege, Izmir, Turkey.
authors.forename: M Erhan
authors.initials: ME
authors.lastname: Comlekoglu
authors.forename: Bulent
authors.initials: B
authors.lastname: Gokce
authors.forename: Aysegul Demirbas
authors.initials: AD
authors.lastname: Kaya
authors.forename: Murat
authors.initials: M
authors.lastname: Turkun
authors.forename: Birgul
authors.initials: B
authors.lastname: Ozpinar
mesh_terms: D000975:Antioxidants / Q000494:pharmacology*; D001205:Ascorbic Acid / Q000494:pharmacology; D000077463:Carbamide Peroxide; D001840:Dental Bonding / Q000379:methods*; D003738:Dental Cements / Q000737:chemistry*; D003799:Dental Stress Analysis; D003804:Dentin / Q000187:drug effects; D017220:Dentin-Bonding Agents / Q000737:chemistry; D006801:Humans; D010545:Peroxides / Q000009:adverse effects; D019279:Resin Cements / Q000737:chemistry*; D033081:Shear Strength; D014073:Tooth Bleaching / Q000009:adverse effects*; D014508:Urea / Q000009:adverse effects / Q000031:analogs & derivatives
chemical_list: D000975:Antioxidants; D003738:Dental Cements; D017220:Dentin-Bonding Agents; D010545:Peroxides; D019279:Resin Cements; D000077463:Carbamide Peroxide; D014508:Urea; D001205:Ascorbic Acid