title: Safety and stability of nightguard vital bleaching: 9 to 12 years post-treatment.
abstract: OBJECTIVE
  The purposes of this retrospective case series study were to evaluate safety issues and determine participants' perceptions of a nightguard vital bleaching (NGVB) technique approximately 10 years post-treatment (average, 118 mo; range, 108-144 mo).
  
  
  METHODS
  The study sample included 30 (79%) of 38 participants who had completed a previous NGVB study using a 10% carbamide peroxide solution (Proxigel or Gly-Oxide) in a custom tray for 6 weeks. Participants were asked whether there had been any change in the shade of their teeth post-treatment and, if so, to quantify the change on a verbal scale. In addition, 19 participants had gingival index and tooth vitality evaluated clinically, external cervical root anatomy evaluated radiographically, and enamel surface changes evaluated microscopically.
  
  
  RESULTS
  Thirty-five (92%) of the original 38 participants had successful lightening of their teeth. At approximately 10 years post-treatment (average, 118 mo; range, 108-144 mo), external cervical resorption was not diagnosed and gingival index and tooth vitality findings were considered within the normal expectations for the sample studied, suggesting minimal clinical post-NGVB side effects at approximately 10 years. Scanning electron microscopic observations did not reveal substantial differences between treated and nontreated surfaces. Color stability, as perceived by 43% of the participants, may last approximately 10 years (average, 118 mo; range, 108-144 mo) post-treatment.
  
  
  CONCLUSIONS
  Nightguard vital bleaching using 10% carbamide peroxide is safe and effective, with no noticeable side effects, at approximately 10 years (average, 118 mo; range, 108-144 mo) post-treatment. Color stability, as perceived by 43% of the participants, may last 108 to 144 months post-whitening.
authors.affiliation: Department of Operative Dentistry, The University of North Carolina School of Dentistry, Chapel Hill 27599-7450, USA. andre_ritter@dentistry.unc.edu
authors.forename: André V
authors.initials: AV
authors.lastname: Ritter
authors.forename: Ralph H
authors.initials: RH
authors.lastname: Leonard
authors.forename: Annie J
authors.initials: AJ
authors.lastname: St Georges
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Caplan
authors.forename: Van B
authors.initials: VB
authors.lastname: Haywood
mesh_terms: D000328:Adult; D000368:Aged; D000077463:Carbamide Peroxide; D003116:Color; D003743:Dental Enamel / Q000473:pathology; D003791:Dental Pulp Test; D004338:Drug Combinations; D004867:Equipment Design; D005500:Follow-Up Studies; D006801:Humans; D008855:Microscopy, Electron, Scanning; D008875:Middle Aged; D016877:Oxidants / Q000008:administration & dosage / Q000627:therapeutic use; D017060:Patient Satisfaction; D010512:Periodontal Index; D010545:Peroxides / Q000008:administration & dosage / Q000627:therapeutic use; D011859:Radiography; D016628:Replica Techniques; D012189:Retrospective Studies; D012391:Root Resorption / Q000145:classification / Q000000981:diagnostic imaging; D012449:Safety; D013997:Time Factors; D014073:Tooth Bleaching / Q000295:instrumentation / Q000379:methods*; D019237:Tooth Cervix / Q000000981:diagnostic imaging / Q000473:pathology; D014508:Urea / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000627:therapeutic use
chemical_list: D004338:Drug Combinations; D016877:Oxidants; D010545:Peroxides; D000077463:Carbamide Peroxide; D014508:Urea