Effect of topical application of nanoencapsulated eugenol on dental sensitivity reduction after in-office dental bleaching: a randomized, triple-blind clinical trial

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 (Delta SGU) and a spectrophotometer ( increment E-ab, increment E-00,E- and WID). The TS was assessed through the McNemar test (alpha = 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 (Delta SGU and Delta E-ab, increment E-00,E- 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.