A clinical, randomized, controlled study on the use of desensitizing agents during tooth bleaching

To evaluate the efficacy of experimental proposals of desensitizing agents during tooth bleaching.

140 participants without tooth sensitivity (TS) received 16% carbamide peroxide (14 days-04 h each) (T1) or 35% hydrogen peroxide (single session-45 min) (T2). Participants used concomitantly (10 per group): desensitizing dentifrices (D1-experimental bioactive glass-ceramic; D2-commercial potassium nitrate; D3-commercial calcium and sodium phosphosilicate) in-home, daily and, desensitizing pastes (D4-experimental bioactive glass-ceramic; D5-experimental Bioglass type 45S5; D6-commercial calcium phosphate), in-office, immediately after the treatment and more 4 times. Participants in the control group did not use any desensitizing agent. We assessed TS with Visual Analogue Scale. Assessment point 1 was immediately after the first participant's exposure to the treatments; and points 2, 3, 4, and 5 were every 72 h along the period of the study. Two-way ANOVA (considering time and desensitizing as factors) and post-hoc Tukey test (α=0.05) analyzed the data.

In the control group treated with 35% hydrogen peroxide, TS increased significantly on assessment points 1 and 2. The participants who used a 5% potassium nitrate dentifrice and in-office experimental pastes did not experience TS because of the 35% in-office bleaching treatment.

TS caused by 35% hydrogen peroxide in-office tooth bleaching was controlled by experimental products prepared as pastes D4-experimental bioactive glass-ceramic and D5-experimental Bioglass type 45S5, but not by D1-experimental dentifrice containing bioactive glass-ceramic.

There is no a gold standard protocol for TS caused by tooth bleaching. The study of novel desensitizing agents that can obliterate the dentinal tubules in a faster-acting and long-lasting way may help meet this clinical need.