title: Effect of light units on tooth bleaching with visible-light activating titanium dioxide photocatalyst.
abstract: This study evaluated the influence of different light sources on the efficiency of an office bleaching agent containing visible-light activating titanium dioxide photocatalyst (VL-TiO(2)) using an artificial discoloration tooth model. Extracted bovine teeth were stained by black tea. The CIE L*a*b* values were measured before and after nine consecutive treatments by the VL-TiO(2)-containing bleaching agent (TiON in Office, GC, Tokyo, Japan). A halogen light unit (CB; CoBee, GC) or an LED unit (G-light, GC) with two modes (blue and violet: GL-BV, blue: GL-B) were used to activate the bleaching agent in three groups (n=8). Brightness (ΔL) and color difference (ΔE) increased as bleaching repeated in all groups. Two-way ANOVA showed that both number of treatments and light sources significantly affected ΔE (p<0.05). GL-BV showed better bleaching effect than GL-B. In measurement of irradiation spectra, CB showed a wide spectrum (380-530 nm), GL-B had a sharp peak at 470 nm and GL-BV showed an additional peak at 405 nm. It was concluded that the light source influenced the efficiency of the tooth bleaching with VL-TiO(2).
authors.affiliation: Cariology and Operative Dentistry, Department of Restorative Sciences, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan.
authors.forename: Ayaka
authors.initials: A
authors.lastname: Kishi
authors.forename: Masayuki
authors.initials: M
authors.lastname: Otsuki
authors.forename: Alireza
authors.initials: A
authors.lastname: Sadr
authors.forename: Masaomi
authors.initials: M
authors.lastname: Ikeda
authors.forename: Junji
authors.initials: J
authors.lastname: Tagami
mesh_terms: D000818:Animals; D000077463:Carbamide Peroxide; D002417:Cattle; D055117:Curing Lights, Dental / Q000145:classification*; D003743:Dental Enamel / Q000187:drug effects / Q000473:pathology; D003804:Dentin / Q000187:drug effects / Q000473:pathology; D006861:Hydrogen Peroxide / Q000627:therapeutic use; D010083:Oxidants, Photochemical / Q000627:therapeutic use; D010084:Oxidation-Reduction; D010545:Peroxides / Q000627:therapeutic use; D055668:Photochemical Processes; D017319:Photosensitizing Agents / Q000627:therapeutic use; D013662:Tea; D014025:Titanium / Q000627:therapeutic use*; D014073:Tooth Bleaching / Q000295:instrumentation*; D058205:Tooth Bleaching Agents / Q000627:therapeutic use*; D014075:Tooth Discoloration / Q000188:drug therapy / Q000473:pathology; D016896:Treatment Outcome; D014508:Urea / Q000031:analogs & derivatives / Q000627:therapeutic use
chemical_list: D010083:Oxidants, Photochemical; D010545:Peroxides; D017319:Photosensitizing Agents; D013662:Tea; D058205:Tooth Bleaching Agents; C009495:titanium dioxide; D000077463:Carbamide Peroxide; D014508:Urea; D006861:Hydrogen Peroxide; D014025:Titanium