Method: The study was approved by Loma Linda University IRB. Subjects (136) 18-75 years of age, with ≥A3 Vita Classical shade (VCS; Bad Säckingen, Germany) on ≥4 of 6 maxillary anterior teeth, were enrolled and randomly assigned to 1) Zoom WhiteSpeed (ZWS, 25% H2O2; Philips, Bothell, WA) or 2) Opalescence Boost PF (OBF, 40% H2O2; Ultradent, South Jordan, UT), with 68 subjects per group. Tooth shade was measured at the baseline (BL), post-bleaching (PB), and day 7 (D7) using L*a*b* (Vita EasyShade), VCS and Vita Bleachedguide 3D-Master (VBG). The bleaching procedures followed manufacturers’ instructions. Clinical safety was evaluated by oral tissue examination and tooth sensitivity questionnaire. The shade and color data were analyzed using ANOVA or Kruskal-Wallis non-parametric analysis.
Result: One subject in the OBF group was withdrawn due to a non-product related reason. Compared to BL, both regimens were effective in whitening teeth (p<0.001). For between-treatment comparisons, the median ΔE for ZWS was greater than OBF for PB (5.12 vs. 2.55; p<0.001) and D7 (6.34 vs. 4.08; p=0.006). Comparison of VCS and VBG shades were also greater for ZWS than OBF [for VSC: LS Mean (SE), -5.86 (0.18) vs. -4.47 (0.18) for PB (p<0.001) and -4.92 (0.20) vs. -4.19 ( 0.20) for D7 (p=0. 01); for VBG: the median shade change was -3.17 vs. -2.00 (p<0.001) for PB and -2.33 vs. -1.67 (p=0.02) for D7]. The incidence of sensitivity and gingival irritation was low and not significantly different between two groups.
Conclusion: Zoom WhiteSpeed and Opalescence Boost are safe and effective in whitening teeth. Zoom WhiteSpeed provides a statistically greater ΔE and shade reduction than Opalescence Boost.