title: Effect of bleaching on color change and refractive index of dental composite resins.
abstract: This study investigated the effects of three bleaching agents (Whiteness Perfect, Whiteness Super, and Whiteness HP) on the color change and refractive index of three dental composites (Admira, Durafill VS, and Gradia Direct). Twenty disk-shaped specimens (10 x 2 mm) of each composite were prepared and divided into four subgroups (n=5). An unbleached group was used as a control, while the remaining specimens in the three subgroups were bleached with one of the bleaching agents respectively. Color change was assessed according to CIELAB color system and refractive indices were determined by phase modulated spectroscopic ellipsometry. Color differences between bleaching and baseline value (DeltaE) were less than 3.3 for all groups. However, bleaching with Whiteness HP led to noticeable color changes for Admira and Durafill VS. While this agent had no effect on the refractive indices of these composites, the other two agents containing carbamide peroxide increased their refractive indices. Therefore, results suggested that replacement of such composite restorations may be required after bleaching.
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Cumhuriyet University, Sivas, Turkey.
authors.forename: Ihsan
authors.initials: I
authors.lastname: Hubbezoglu
authors.forename: Bariş
authors.initials: B
authors.lastname: Akaoğlu
authors.forename: Arife
authors.initials: A
authors.lastname: Dogan
authors.forename: Selda
authors.initials: S
authors.lastname: Keskin
authors.forename: Giray
authors.initials: G
authors.lastname: Bolayir
authors.forename: Süleyman
authors.initials: S
authors.lastname: Ozçelik
authors.forename: Orhan Murat
authors.initials: OM
authors.lastname: Dogan
mesh_terms: D000077463:Carbamide Peroxide; D002516:Ceramics / Q000737:chemistry; D003116:Color; D003188:Composite Resins / Q000737:chemistry*; D003764:Dental Materials / Q000737:chemistry*; D004338:Drug Combinations; D006801:Humans; D006861:Hydrogen Peroxide / Q000737:chemistry; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D063225:Organically Modified Ceramics; D016877:Oxidants / Q000737:chemistry*; D010545:Peroxides / Q000737:chemistry; D012031:Refractometry; D012821:Silanes / Q000737:chemistry; D012833:Siloxanes / Q000737:chemistry; D013057:Spectrum Analysis; D013499:Surface Properties; D014073:Tooth Bleaching; D014508:Urea / Q000031:analogs & derivatives / Q000737:chemistry
chemical_list: D003188:Composite Resins; D003764:Dental Materials; D004338:Drug Combinations; C470230:Gradia; D008689:Methacrylates; D063225:Organically Modified Ceramics; D016877:Oxidants; D010545:Peroxides; D012821:Silanes; D012833:Siloxanes; C479084:admira; D000077463:Carbamide Peroxide; C039734:Durafill; D014508:Urea; D006861:Hydrogen Peroxide