title: Improved tooth bleaching combining ozone and hydrogen peroxide--A blinded study.
abstract: OBJECTIVE
  To evaluate the efficacy of tooth bleaching using ozone after hydrogen peroxide (H2O2) in comparison to the use of H2O2 alone.
  
  
  METHODS
  70 extracted teeth were randomly distributed into two groups. Teeth surfaces in group 1 (n=35) were treated using 38% H2O2 and then were exposed to ozone for 60s and this ozonated peroxide mixture was left on the teeth for 20 min. Meanwhile, teeth in group 2 (n=35) were treated with H2O2 38% for 20 min. The L* a* b* and Vita Classic shade values of teeth were evaluated in both groups at base line, after application of H2O2 and ozone in group 1, and after application of H2O2 and then again after another application of ozone in group 2. The statistically significant changes were set at P ≤ 0.05.
  
  
  RESULTS
  Baseline L* a* b* and Vita shade values were comparable between groups (P>0.05). Teeth obtained lighter shades following bleaching with both H2O2 and ozone or with H2O2 alone (P ≤ 0.05). Further bleaching with ozone for teeth already bleached with H2O2 alone showed further improvement of the shades of teeth (P<0.001). Teeth treated with H2O2 and ozone had more shade improvements than those only treated with H2O2 (P<0.001). Also, L* values were increased while b* values were decreased (teeth obtained lighter shades) following bleaching in both groups (P ≤ 0.05). More changes were obtained when both ozone and H2O2 were used (P ≤ 0.05).
  
  
  CONCLUSIONS
  Bleaching with 38% H2O2 and ozone resulted in teeth with lighter shades than bleaching with 38% H2O2 alone.
authors.affiliation: Faculty of Dentistry, University of Jordan, Amman, Jordan; The City of London School of Dentistry, BPP University, UK. Electronic address: alomirim@yahoo.co.uk.
authors.forename: Mahmoud K
authors.initials: MK
authors.lastname: Al-Omiri
authors.affiliation: Faculty of Allied Medical Sciences, The Royal University for Medical Sciences, Amman, Jordan.
authors.forename: Ra'ed S
authors.initials: RS
authors.lastname: Abul Hassan
authors.affiliation: Faculty of Dentistry, AlJouf University, Sakaka, Saudi Arabia.
authors.forename: Bader K
authors.initials: BK
authors.lastname: AlZarea
authors.affiliation: Warwick Medical School, Coventry CV4 7AL, UK.
authors.forename: Edward
authors.initials: E
authors.lastname: Lynch
mesh_terms: D001641:Bicuspid / Q000187:drug effects; D003116:Color; D003124:Colorimetry; D003481:Cuspid / Q000187:drug effects; D003743:Dental Enamel / Q000187:drug effects; D006801:Humans; D006861:Hydrogen Peroxide / Q000008:administration & dosage*; D007180:Incisor / Q000187:drug effects; D010126:Ozone / Q000008:administration & dosage*; D011897:Random Allocation; D013499:Surface Properties; D014073:Tooth Bleaching / Q000379:methods*; D014075:Tooth Discoloration / Q000188:drug therapy
chemical_list: D010126:Ozone; D006861:Hydrogen Peroxide
keywords: Bleaching; HealOzone; Hydrogen peroxide; Ozone; Tooth shade