Efetividade do Gel de Nitrato de Potássio 6% na sensibilidade do clareamento dentário de consultório - estudo clínico randomizado

Abstract

This randomized controlled clinical trial evaluated the efficacy of a desensitizing gel, containing 6% potassium nitrate and 0.11% fluorine (PN), previously applied to dental bleaching (35% hydrogen peroxide) (HP) in adults. Thirty-one patients had their maxilar anterior teeth divided into left and right, according to the application of a placebo gel (Control Group - HP35/P) or desensitizing (Experimental Group - HP35/PN) in a split-mouth design. In HP35/P the placebo gel was applied on the buccal surfaces of a hemiarch for 30 min prior to the bleaching treatment and in HP35/PN the desensitizing agent was similarly applied to the other hemiarch in two bleaching sessions. After geals removal, both sides were bleached with HP35 for 24 minutes. Changes in color were checked at the beginning (T1), before the second bleaching session (T2), 7 (T3) and 30 (T4) days after the end of the bleaching, with two shade guides and a spectrophotometer. Tooth sensitivity (TS) was recorded by a sensitivity diary answered by the patient, within 48 hours after each bleaching session. Color alteration was assessed by changes in shade guide units (SGU) and by ΔE value, wich were compared by t Student test (=5%). TS absolute risk was compared by McNemar test and TS intensity by Wilcoxon (=5%). Color alteration was assessed by changes in shade guide units (SGU) and by ΔE value, wich were compared by t Student test (=5%). No significant difference between treatments was observed with concern to TS absolute risk (p=0.59). TS intensity was higher within the first 24 hours. Effectiveness was the same for both treatments (SGU 7.8 ± 2.9 and 7.9 ± 2.7, and E 9 ± 5.1 e 9.3 ± 5.2). After two bleaching sessions, the use of a desensitizing gel did not reduce the absolute risk nor the TS intensity. The use of desensitizing gel did not reduce in office dental bleaching efficacy.