Increased whitening efficacy and reduced cytotoxicity are achieved by the chemical activation of a highly concentrated hydrogen peroxide bleaching gel

• Autor(a) principal: Soares, Diana Gabriela
• Data de Publicação: 2022
• Outros Autores: Marcomini, Natália, Duque, Carla Caroline de Oliveira, Bordini, Ester Alves Ferreira, Zuta, Uxua Ortecho, Basso, Fernanda Gonçalves, Hebling, Josimeri, Costa, Carlos Alberto de Souza
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Journal of applied oral science (Online)
• Texto Completo: https://www.revistas.usp.br/jaos/article/view/200658
• topic: Tooth bleaching; Dental pulp; Cytotoxicity; Odontoblasts

Objective: This study was designed for the chemical activation of a 35% hydrogen peroxide (H2O2) bleaching gel to increase its whitening effectiveness and reduce its toxicity. Methodology: First, the bleaching gel - associated or not with ferrous sulfate (FS), manganese chloride (MC), peroxidase (PR), or catalase (CT) - was applied (3x 15 min) to enamel/dentin discs adapted to artificial pulp chambers. Then, odontoblast-like MDPC-23 cells were exposed for 1 h to the extracts (culture medium + components released from the product), for the assessment of viability (MTT assay) and oxidative stress (H2DCFDA). Residual H2O2 and bleaching effectiveness (DE) were also evaluated. Data were analyzed with one-way ANOVA complemented with Tukey’s test (n=8. p<0.05).Results: All chemically activated groups minimized MDPC-23 oxidative stress generation; however, significantly higher cell viability was detected for MC, PR, and CT than for plain 35% H2O2 gel. Nevertheless, FS, MC, PR, and CT reduced the amount of residual H2O2 and increased bleaching effectiveness.Conclusion: Chemical activation of 35% H2O2 gel with MC, PR, and CT minimized residual H2O2 and pulp cell toxicity; but PR duplicated the whitening potential of the bleaching gel after a single 45-minute session.