title: Single site meta-analysis of 6% hydrogen peroxide whitening strip effectiveness and safety over 2 weeks.
abstract: OBJECTIVE
  This research evaluated efficacy and safety of 6% hydrogen peroxide whitening strips from a clinical trials database accumulated over a multi-year period at a single site.
  
  
  METHODS
  The inclusive meta-analysis involved seven different randomized clinical trials at one dental school. Each study used 6% hydrogen peroxide whitening strips twice daily for 30min over a 2-week period. Common efficacy (digital images) and safety (examination and interview) methods were used across studies. Pooled subject-level data were analyzed using a general linear mixed model to determine overall response and effects of treatment duration on whitening.
  
  
  RESULTS
  The 148 treated subjects were 18-71 years old, with b* (yellowness) ranging from 12 to 22, and L* (lightness) ranging from 69 to 80. After 1-week strip use, the adjusted mean (S.E.) for Deltab* was -1.6 (0.08), differing significantly from baseline (p<0.0001). After 2 weeks, the adjusted mean (S.E.) for Deltab* was -2.3 (0.07), differing significantly from Week 1 (p<0.0001). The estimated correlation between Weeks 1 and 2 for Deltab* was 0.74. Study-to-study variation contributed less than 2% of Deltab* variability. Results were similar for DeltaL*, with Weeks 1 and 2 estimated means (S.E.) of 1.5 (0.13) and 2.0 (0.12). Occurrence of oral irritation (22%) and tooth sensitivity (20%) did not adversely affect whitening. Other side effects were unremarkable, and only 1 subject (0.7%) discontinued treatment early due to an adverse event.
  
  
  CONCLUSIONS
  The meta-analysis of multiple studies conducted at a single clinical site over several years establishes consistent, effective and safe vital bleaching with 6% hydrogen peroxide whitening strips.
authors.affiliation: The Procter & Gamble Company, Mason, OH 45040-8006, USA. gerlach.rw@pg.com
authors.forename: Robert W
authors.initials: RW
authors.lastname: Gerlach
authors.forename: Matthew L
authors.initials: ML
authors.lastname: Barker
authors.forename: Katherine
authors.initials: K
authors.lastname: Karpinia
authors.forename: Ingvar
authors.initials: I
authors.lastname: Magnusson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D064420:Drug-Related Side Effects and Adverse Reactions; D005260:Female; D006801:Humans; D006861:Hydrogen Peroxide / Q000627:therapeutic use / Q000633:toxicity; D008297:Male; D008875:Middle Aged; D016877:Oxidants / Q000627:therapeutic use / Q000633:toxicity; D016032:Randomized Controlled Trials as Topic; D014073:Tooth Bleaching / Q000379:methods*; D014075:Tooth Discoloration / Q000188:drug therapy*; D055815:Young Adult
chemical_list: C488279:Crest whitestrips; D016877:Oxidants; D006861:Hydrogen Peroxide