title: Clinical comparison between two bleaching techniques: a 180-day follow-up study.
abstract: OBJECTIVE
  The aim of this clinical study was to compare tooth shade, color rebound, and tooth sensitivity after using either a combined bleaching technique (CBT) or a deep bleaching technique (DBT) to lighten stained teeth. CBT is a two-stage bleaching process consisting of an initial in-office bleaching treatment session using 35% hydrogen peroxide (HP) followed by a 7-day at-home bleaching session with 6% HP. DBT involves a 7-day at-home bleaching session with 6% HP prior to the initiation of a two-stage CBT process.
  
  
  METHODS
  Thirty-six volunteers were recruited in this split-mouth design randomized clinical trial. Tooth shade was objectively evaluated by using a spectrophotom-eter and shade guide tabs. Tooth and gingival tissue sensitivity were self-evaluated by recording any tooth or gingival sensitivity on a daily basis.
  
  
  RESULTS
  Both CBT and DBT presented satisfactory whitening effects. Although DBT resulted in a better shade change, the two bleaching techniques had a similar rebound effect. CBT was associated with a lower frequency of tooth sensitivity, but both bleaching techniques can be considered safe from a clinical standpoint.
  
  
  CONCLUSIONS
  The results indicate that CBT might potentially be preferred to whiten teeth, thus promoting the shade change, and avoiding gingival and tooth sensitivity.
authors.affiliation: Department of Prothodontics, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University, Guangzhou, PR China. zhaoke@mail.sysu.edu.cn
authors.forename: Ke
authors.initials: K
authors.lastname: Zhao
authors.forename: Li
authors.initials: L
authors.lastname: Zong
authors.forename: Qin
authors.initials: Q
authors.lastname: Zhang
authors.forename: Wael
authors.initials: W
authors.lastname: Att
mesh_terms: D000328:Adult; D003116:Color; D003124:Colorimetry; D003807:Dentin Sensitivity / Q000209:etiology; D005260:Female; D005500:Follow-Up Studies; D005881:Gingiva / Q000187:drug effects; D006801:Humans; D006861:Hydrogen Peroxide / Q000008:administration & dosage / Q000627:therapeutic use; D008297:Male; D023861:Photography, Dental; D013053:Spectrophotometry; D014070:Tooth / Q000187:drug effects / Q000473:pathology; D014073:Tooth Bleaching / Q000295:instrumentation / Q000379:methods*; D058205:Tooth Bleaching Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D014075:Tooth Discoloration / Q000188:drug therapy; D064232:Visual Analog Scale; D055815:Young Adult
chemical_list: D058205:Tooth Bleaching Agents; D006861:Hydrogen Peroxide