26054177
OBJECTIVE	To evaluate the effectiveness and tolerability of an experimental 9.5 % hydrogen peroxide whitening strip relative to a placebo control over a three-week period .
METHODS	In this parallel-design , double-blind clinical trial , 54 adult volunteers were randomized to an experimental 9.5 % hydrogen peroxide whitening strip or placebo strip balancing for age and baseline tooth color , and received treatment .
METHODS	Strips were worn on the maxillary arch 30 minutes daily for 20 days .
METHODS	Efficacy was measured objectively as L * a * b * color change from digital images at Days 4 , 7 , 15 , and 21 .
RESULTS	As early as Day 4 and at all subsequent visits , the 9.5 % strip group experienced significant ( p < 0.004 ) color improvement relative to placebo for b * and L * color parameters .
RESULTS	The amount of color improvement increased with continuing peroxide strip use .
RESULTS	Mean SE between-group differences in Ab * were -0.6 0.16 , -0.8 0.15 , -1.6 0.19 , and -1.9 0.20 at Days 4 , 7 , 15 , and 21 , respectively .
RESULTS	Similar results were noted for AL * .
RESULTS	Minor tooth sensitivity was the most common adverse event , as reported by 12 % of subjects in the 9.5 % strip group and 11 % of subjects in the placebo group .
RESULTS	No subjects discontinued treatment due to an adverse event .
CONCLUSIONS	This placebo-controlled clinical trial demonstrated that an experimental 9.5 % hydrogen peroxide strip yielded significant tooth whitening relative to a placebo strip as early as after three days of product use .

