RESUMO
PURPOSE: This randomized, split-mouth, triple-blind clinical study evaluated the effect of application of nanoencapsulated eugenol (NE) on the absolute risk and intensity of tooth sensitivity (TS) resulting from in-office bleaching. METHODS: Fifty-six patients received a NE in one hemiarch and a placebo gel in the other hemiarch, determined by random sequence, before in-office bleaching. A visual analogue scale (VAS) (0-10) and a numeric rating scale (NRS) (0-4) were used to record TS during bleaching and 1 and 48 h after bleaching. The tooth color was performed from baseline to 2 weeks after bleaching with shade guides (ΔSGU) and a spectrophotometer (∆Eab , ∆E00, and WID ). The TS was assessed through the McNemar test (α = 0.05) and by the Wilcoxon signed-rank test (NRS) and paired t-test (VAS). The paired test-t was employed to compare the color changes (ΔSGU and ΔEab , ∆E00, and WID ). The significance level was 5%. RESULTS: No statistically significant difference was found in the absolute risk or intensity of TS between both groups (p > 0.05). A significant color change was observed in both groups (p > 0.05). CONCLUSION: Administration of the gel containing NE before the in-office dental bleaching did not reduce the TS and did not interfere in the bleaching effect. CLINICAL RELEVANCE STATEMENT: The use of desensitizing gel containing NE did not reduce in-office bleaching-induced tooth sensitivity.