Clinical study to compare two in-office (chairside) whitening systems

The objective of this clinical study was to compare the whitening/bleaching efficacy of two marketed in-office whitening systems: Discus Dental Zoom! Chairside System (25% hydrogen peroxide whitening gel) and Opalescence Xtra Boost Kit (38% hydrogen peroxide whitening gel), using the Vita Shade Guide and chromameter measurements. The study was an examiner-blind, parallel group, randomized and controlled clinical trial conducted in a dental setting. All subjects signed a study consent form prior to admission and were given Crest Regular Toothpaste and an Oral-B 40 straight-handle toothbrush to use during the study. Subjects received a supragingival prophylaxis followed by a screening eligibility Vita Shade assessment from which 22 subjects were selected. At baseline, all six maxillary anterior teeth were assessed with the Vita Shade Guide. Chromameter measurements were taken on either the right maxillary central or left maxillary central (tooth No. 8 or tooth No. 9). Subjects were assigned to one of two treatment groups, and had three applications of their assigned product. Following completion of the treatment phase, and on post-treatment Days 2 and 7, a visual examination of the condition of the oral soft tissues, together with a Vita Shade assessment on maxillary anterior teeth, a chromameter reading and a questionnaire regarding tooth sensitivity were completed. At the termination of the study, the statistical analysis of the Vita Shade scores indicated that both products significantly (p < 0.0001) lightened the color of the teeth. The average improvement was between 6 and 9 shade changes. Additionally, the Zoom! Chairside System was significantly better than the Opalescense Xtra Boost Kit at all time points: post-treatment (p < 0.0001); Day 2 (p < 0.004); Day 7 (p < 0.003). This difference was between 1 and 2 shade changes. The chromameter readings showed a significant difference in the overall color change (delta E) to a lighter color for both the Zoom! Chairside System and the Opalescence Xtra Boost Kit. Using delta E, the Zoom! Chairside System was directionally better than the Opalescense Xtra Boost Kit at Day 2 (p < 0.08), and significantly better at Day 7 (p < 0.025). Analysis of the composite parameters of delta E (L*, a*, b*) showed that no differences could be detected in the a* (redness) parameter. Changes were observed in the L* (brightness) and b* (yellow) parameters which paralleled the delta E differences. There were no significant differences in induced sensitivity between whitening systems at any time point.