In-office Bleaching With a 2-day Interval Between Sessions: Tooth Sensitivity

The in-office bleaching uses 35% hydrogen peroxide gel which is applied in 2 to 3 sessions usually with one week interval between sessions, without a scientific and plausible reason for this recommendation (. The aim of this study was to evaluate the tooth sensitivity (TS) risk using a shorter interval between clinical sessions. Methods: In this randomized, single-blind study, 40 young patients with color C2 or darker were selected and randomly divided in two groups. In the 7-day group, two bleaching sessions with a 35% hydrogen peroxide gel (Whiteness HP Blue Calcium - FGM) were performed with a one-week interval and in the 2-day group, the same protocol was performed but with a 2-day interval. TS was recorded on a 0-10 visual analog scale up to 48 h after bleaching. The color evaluation was performed at baseline and 30 days after bleaching with a value-oriented shade guide and a spectrophotometer. The absolute risk of TS (%) was evaluated by Fisher´s exact. The TS intensity was evaluated by two-way repeated measured ANOVA and color changes (ΔSGU and ΔE) were evaluated by Student´s t-test (alpha = 5%).