title: Effect of bleaching on vital discoloured teeth--a colorimetric evaluation in three patients.
abstract: Vital bleaching is considered effective for reduction of tooth discolouration. This evaluation was to measure colour changes before and after bleaching of vital tetracycline-discoloured teeth in three patients. Vital bleaching of their anterior maxillary teeth was performed five times at weekly intervals. Tooth colour was measured with a small-area colorimeter before, immediately and two, four and six months after bleaching. The results were expressed in the CIE L*a*b* colour system. The L* value, a lightness variable, increased after bleaching. The a* value changed only negligibly, but the b* value decreased after bleaching showing changes in the tooth colour from yellow to blue. The colour differences before treatment and six months after bleaching was visually perceivable.
authors.affiliation: Department of Fixed Prosthodontics and Occlusion, Faculty of Dentistry, Osaka University, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Nakamura
authors.forename: H
authors.initials: H
authors.lastname: Nakajima
authors.forename: P
authors.initials: P
authors.lastname: Salimee
authors.forename: T
authors.initials: T
authors.lastname: Hino
authors.forename: T
authors.initials: T
authors.lastname: Maruyama
mesh_terms: D000328:Adult; D003116:Color / Q000592:standards; D003124:Colorimetry; D006801:Humans; D013752:Tetracycline / Q000009:adverse effects; D014073:Tooth Bleaching; D014075:Tooth Discoloration / Q000209:etiology / Q000628:therapy*
chemical_list: D013752:Tetracycline