Effects of Enzymatic Activation of Bleaching Gels on Hydrogen Peroxide Degradation Rates, Bleaching Effectiveness, and Cytotoxicity

Autor(es)

Ortecho-Zuta, U. ^[1] ; de Oliveira Duque, C. C. ^[1] ; Leite, M. L. ^[1] ; Bordini, E. A. F. ^[1] ; Basso, F. G. ^[2] ; Hebling, J. ^[3] ; de Souza Costa, C. A. ^[2] ; Soares, D. G. ^[4]

Afiliação do(s) autor(es)

^[1] Univ Estadual Paulista UNESP, Dept Dent Mat & Prosthodont, Araraquara Sch Dent, Araraquara, SP - Brazil

^[2] Univ Estadual Paulista UNESP, Araraquara Sch Dent, Dept Physiol & Pathol, Araraquara, SP - Brazil

^[3] Univ Estadual Paulista UNESP, Araraquara Sch Dent, Dept Orthodont & Pediat Dent, Araraquara, SP - Brazil

^[4] Sao Paulo Univ USP, Dept Operat Dent Endodont & Dent Mat, Bauru Sch Dent, Bauru, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Operative Dentistry; v. 44, n. 4, p. 414-423, JUL-AUG 2019.
• Citações Web of Science: 1

Resumo

Objectives: The aim of this study was to evaluate the effect of horseradish peroxidase (HRP) on the release of free radicals, bleaching effectiveness, and indirect cytotoxicity of a 35% hydrogen peroxide (HP) bleaching gel. Methods and Materials: First, HP degradation rates and free radical release were evaluated for 35% HP in contact or not with HRP (10 mg/mL). The bleaching gel associated or not with HRP was then applied (3 X 15 minutes) to enamel/dentin discs adapted to artificial pulp chambers, and the culture medium in contact with dentin surfaces (extract) was collected and exposed to cultured odontoblast-like cells. Membrane damage and viability of cells as well as oxidative stress were evaluated. Residual HP/free radical diffusion was quantified, and bleaching effectiveness (Delta E) was assessed. Unbleached discs served as negative controls. Results: The addition of HRP to the 35% HP bleaching gel enhanced the release of free radicals in comparison with plain HP gel. The 35% HP-mediated cytotoxicity significantly decreased with HRP in the bleaching gel and was associated with reduced HP/free radical diffusion through the enamel/dentin discs. Delta E values increased every bleaching session for HRP-containing gel relative to positive control, accelerating the whitening outcome. Conclusion: The enzymatic activation of a 35% HP bleaching gel with HRP accelerated HP degradation mediated by intensification of free radical release. This effect optimized whitening outcome as well as minimized residual HP and free radical diffusion through enamel and dentin, decreasing the harmful effects on odontoblast-like cells. (AU)

• Processo FAPESP: 16/15674-5 - Associação de técnicas de engenharia tecidual para modulação da regeneração de tecidos mineralizados sob inflamação degenerativa: análise em modelos de cultura-3D em biorreator de perfusão e inflamatórios em animais
• Beneficiário: Diana Gabriela Soares dos Passos
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores
• Processo FAPESP: 15/21770-4 - Desenvolvimento de produtos clareadores dentais experimentais baseados em princípios dos processos oxidativos avançados: análise dos efeitos estéticos e biológicos
• Beneficiário: Carlos Alberto de Souza Costa
• Modalidade de apoio: Auxílio à Pesquisa - Regular