Search

Bleaching protocols using low concentration hydrogen peroxide (HP) photoactivated with LED sources have been widely discussed. Herein, we evaluated the whitening efficacy of 15% HP photoactivated with blue or violet LED compared to 35% HP.Thirty bovine crowns were sectioned into 5 × 5 × 2 mm specimens. After staining in black tea, the specimens were randomized into three groups (n = 10): 35% HP, 15% HP + blue LED and 15% HP + violet LED. Two bleaching sessions were performed and the color assessment (∆L*, ∆a*, ∆b*, ∆EAll groups showed effective and similar results over 1 month of follow-up (p 0.05), with only intragroup differences among the time intervals (p 0.05).The use of 15% HP photoactivated with blue or violet LED showed similar whitening efficacy compared to 35% HP. Thus, the association of low concentration bleaching gels with blue or violet LED sources can provide successful and less-aggressive treatment in terms of color change.

This study aimed to evaluate the bleaching efficacy, pH, and temperature of 35% hydrogen peroxide (HP) gel used alone or associated with violet LED.Sixty bovine crowns were sectioned (5 × 5 × 2mm). After staining with black tea, the specimens were randomized into four groups (n = 10) according to the bleaching protocol: HP35R: 3 × 15 min 35% HP; HP35: 1 × 45 min 35% HP; HP35VR: 3 × 8min 35% HP + Violet LED; HP35V: 1 × 24 min + Violet LED. Two bleaching sessions were performed for all the groups. Color change was evaluated before, 24h after each session, 7 days and 15 days after the last session. The variables ∆EHP35VR and HP35V the most noticeable color change(p 0.05). The final values of pH were lower than the initial ones, but with no difference between the groups (p 0.05). Groups HP35VR and HP35V showed an increase in temperature in relation to HP35R (p 0.05).Violet LED improved the bleaching efficacy of 35% HP in a time-saving manner without negatively affecting the pH and temperature of 35% HP. The renewal of HP did not influence the outcomes.