Purpose: To compare the clinical response of two self-directed vital bleach
ing systems under market use conditions. Materials and Methods: A randomize
d, parallel-group clinical trial was conducted. A total of 20 healthy adult
s were randomized to either a 6.0% hydrogen peroxide strip-based bleaching
system or a combination system involving a 10% carbamide peroxide gel in a
stock tray along with an anticavity whitening dentifrice and after-bleachin
g whitening mouthrinse. Only the maxillary arch was bleached over a 14-day
period. Subjects were evaluated at 3, 8 and 15 days. Efficacy was measured
objectively using digital image analysis to derive individual color paramet
ers (L*a*b*) and overall color change (DeltaE*). Results: After 14 days, th
e adjusted mean reduction in yellow (Deltab*) was -2.23 +/- 0.157 for the w
hitening strips compared to -0.97 +/- 0.188 for the combination system. Thi
s represented a highly statistically significant (P < 0.0001), two-fold sup
erior reduction in yellowness for the whitening strip group compared to the
marketed control. Similar results were seen for other color parameters, wi
th the whitening strip group exhibiting twofold color improvement relative
to the tray/dentifrice/rinse combination. With respect to tolerability, too
th sensitivity and oral irritation were the most common findings. Consideri
ng event duration and severity, median bleaching tolerability severity-days
scores were 0.07 and 0.58 for the strip and combination systems respective
ly, with these treatments differing statistically (P= 0.041) favoring the w
hitening strips.