Objectives: This study will determine the effectiveness of preemptive administration of
etodolac on risk and intensity of tooth sensitivity caused by in-office bleaching using 35%
hydrogen peroxide.
Materials and Methods: Fifty patients will be selected for this triple-blind, randomized,
cross-over, placebo-controlled clinical trial. Etodolac (400 mg) or placebo will be
administrated in a single-dose 1 hour prior to bleaching procedure. The whitening treatment
with 35% hydrogen peroxide will be carried out in two sessions with a 7-day interval. Tooth
sensitivity will be assessed before, during and 24 hours after the procedure using analog
visual and verbal scales. Color alteration will be assessed by a bleach guide scale 7 days
after each session. Relative risk to sensitivity will be calculated and adjusted by session;
while comparison of overall risk will performed by McNemar's test. Data on the sensitivity
level for both scales and color shade will be subjected to the Friedman, Wilcoxon and
Mann-Whitney tests, respectively (α = 0.05).