title: Comparison of at-home and in-office tooth whitening using a novel shade guide.
abstract: OBJECTIVE
  This study evaluated the time necessary for at-home whitening (HW) to match the results of an in-office (OW) treatment, side effects and patients' preferences/perceptions.
  
  
  METHODS
  The tooth color change of 20 subjects was measured using a shade guide (BSG) and spectrophotometer (ES). Color difference was calculated: delta E* = [(delta L*)2 + (delta a*ab)2 + (delta b*ab)2]1/2. The whitening treatments were randomly applied to the right or left maxillary anterior teeth, in-office, with 25% hydrogen peroxide or at-home, overnight, with 10% carbamide peroxide. The tooth color was evaluated at baseline, one day after OW, six days (five days after HW) and at 20 days (14 days after HW and 19 days OW). Subjects rated their tooth and soft tissue sensitivity (1-10 scale). The results were analyzed by two-way RM ANOVA/Tukey's and Mann-Whitney (p<0.05).
  
  
  RESULTS
  At six days, the teeth that were treated with HW and OW presented delta E* = 5.2 and 6.6, respectively, delta BSG = 3, and at 20 days, they presented delta E* = 6.2 and 6.6, respectively, delta BSG = 3. Less than 40% of the subjects experienced tooth sensitivity after OW and HW. No subjects experienced tooth and gingival sensitivity at 20 days. Seventy-four percent preferred HW over OW, 63% recommended OW and 100% recommended HW.
  
  
  CONCLUSIONS
  While there was a subtle difference in delta E* between HW and OW at six days, the measurement of delta E* and delta BSG agreed that five days of home whitening produced the same results as a single in-office treatment. The tissue and teeth sensitivity were mild and transient. Subjects preferred and would recommend HW over OW.
authors.affiliation: Oregon Health & Science University, Restorative Dentistry, Portland, OR, USA. dacostaj@ohsu.edu
authors.forename: Juliana B
authors.initials: JB
authors.lastname: da Costa
authors.forename: Rosemary
authors.initials: R
authors.lastname: McPharlin
authors.forename: Rade D
authors.initials: RD
authors.lastname: Paravina
authors.forename: Jack L
authors.initials: JL
authors.lastname: Ferracane
mesh_terms: D000328:Adult; D000077463:Carbamide Peroxide; D003116:Color; D003770:Dental Offices; D003807:Dentin Sensitivity / Q000145:classification; D005260:Female; D005500:Follow-Up Studies; D005881:Gingiva / Q000187:drug effects; D006801:Humans; D006861:Hydrogen Peroxide / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D016877:Oxidants / Q000008:administration & dosage / Q000627:therapeutic use; D057240:Patient Preference; D017060:Patient Satisfaction; D010545:Peroxides / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use; D012648:Self Care; D016037:Single-Blind Method; D013053:Spectrophotometry; D013997:Time Factors; D014070:Tooth / Q000033:anatomy & histology*; D014073:Tooth Bleaching / Q000009:adverse effects / Q000379:methods*; D014508:Urea / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives / Q000627:therapeutic use; D055815:Young Adult
chemical_list: D016877:Oxidants; D010545:Peroxides; D000077463:Carbamide Peroxide; D014508:Urea; D006861:Hydrogen Peroxide