At-home bleaching with carbamide peroxide with concentrations below 10%: bleaching efficacy and permeability in the pulp chamber

• Published in: Clinical oral investigations 2024-03, Vol.28 (4), p.224-224, Article 224
• Main Authors: Cordeiro, Deisy Cristina Ferreira, Favoreto, Michael Willian, Centenaro, Gabrielle Gomes, Gumy, Fernanda Novak, Loguercio, Alessandro D., Borges, Christiane Philippini Ferreira, Reis, Alessandra
• Format: Article
• Language: English
• Subjects: Bleaching; Carbamide Peroxide; Dental pulp; Dental Pulp Cavity; Dentistry; Gels; Humans; Hydrogen Peroxide; Hypochlorous Acid; Medicine; Permeability; Peroxides - pharmacology; Premolars; Spectrophotometry; Time; Tooth Bleaching - methods; Tooth Bleaching Agents - pharmacology; Urea - pharmacology; Variance analysis
• ISSN: 1436-3771; 1432-6981; 1436-3771
• DOI: 10.1007/s00784-024-05604-7

Objectives To evaluate the bleaching efficacy and permeability of hydrogen peroxide (HP) in the pulp chamber of human teeth bleached with lower concentrations of carbamide peroxide gel (4%, 5% and 7% CP). Materials and methods Bleaching gels with lower concentrations were formulated and a commercial standard gel, 10% CP, was used as a reference. Fifty-six human premolars were randomly divided into four groups. Applications of the bleaching gel were made for 3 h for 21 days. The bleaching efficacy was evaluated by digital spectrophotometry on 1, 7, 14 and 21 days, with analysis in the ∆E ab , ∆E 00 and WI D color spaces. The concentration of HP in the pulp chamber was measured in the same periods by UV-Vis spectrophotometry (µg/mL). Two-way repeated analysis of variance (ANOVA) examined bleaching efficacy and HP permeability, followed by Tukey’s post-hoc test (α = 0.05). Results All groups showed significant color changes, with no statistical differences after the second and third week of bleaching ( p  > 0.05). The ‘time’ factor was statistically different ( p