title: Comparison of three in-office bleaching systems based on 35% hydrogen peroxide with different light activators.
abstract: OBJECTIVE
  To compare in vitro the bleaching effects obtained with and without the use of the various lights on power bleaching systems.
  
  
  METHODS
  19 groups of five tooth specimens were prepared and allocated randomly to treatments. Only specimens with shade C4 were accepted for the study. Three commercial bleaching products all based on 35% hydrogen peroxide were used with and without four different light sources. Shade assessments were made using a Shade Guide (SG), Shade Vision System (SVS) and chromometer.
  
  
  RESULTS
  For SG, all but the light only treatment resulted in measurable improvement in shade ranging from 4.6 to 14.6 shade guide units. Similar findings were apparent with SVS and chromometer. No change was seen in the light only treatments by SVS or SG with very small changes by chromometer. In mean terms with all three gels, least change was noted when there was no light used. For SG, SVS and chromometer data analysis over all treatment groups, excluding light only treatments, revealed highly significant differences. Within bleach product treatment differences were only significant with one gel both with and without light activation. Differences between gels with the same light and no light revealed some significant differences in SG and chromometer data but not SVS. In mean terms the order of efficacy of gels with each light and no light was the same for the majority of data sets.
authors.affiliation: Division of Restorative Dentistry, Dept. Oral & Dental Science, University of Bristol Dental School, Lower Maudlin St., Bristol BS1 2LY, United Kingdom.
authors.forename: Munther
authors.initials: M
authors.lastname: Sulieman
authors.forename: Emma
authors.initials: E
authors.lastname: MacDonald
authors.forename: Jeremy S
authors.initials: JS
authors.lastname: Rees
authors.forename: Martin
authors.initials: M
authors.lastname: Addy
mesh_terms: D000704:Analysis of Variance; D003116:Color; D003748:Dental Equipment; D006219:Halogens; D006801:Humans; D006861:Hydrogen Peroxide; D008027:Light; D016877:Oxidants; D012666:Semiconductors; D014073:Tooth Bleaching / Q000379:methods*; D014978:Xenon
chemical_list: D006219:Halogens; D016877:Oxidants; D014978:Xenon; D006861:Hydrogen Peroxide