Concentrations of and application protocols for hydrogen peroxide bleaching gels: Effects on pulp cell viability and whitening efficacy

Autor(es)

Soares, Diana Gabriela ^[1] ; Basso, Fernanda Goncalves ^[2] ; Hebling, Josimeri ^[3] ; de Souza Costa, Carlos Alberto ^[2]

Afiliação do(s) autor(es)

^[1] Univ Estadual Paulista, UNESP, Dept Dent Mat & Prosthodont, Araraquara Sch Dent, BR-14801903 Araraquara, SP - Brazil

^[2] Univ Estadual Paulista, UNESP, Dept Physiol & Pathol, Araraquara Sch Dent, BR-14801903 Araraquara, SP - Brazil

^[3] Univ Estadual Paulista, UNESP, Dept Orthodont & Pediat Dent, Araraquara Sch Dent, BR-14801903 Araraquara, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of Dentistry; v. 42, n. 2, p. 185-198, FEB 2014.
• Citações Web of Science: 49

Resumo

Objectives: To assess the whitening effectiveness and the trans-enamel/trans-dentinal toxicity of experimental tooth-bleaching protocols on pulp cells. Methods: Enamel/dentine discs individually adapted to trans-well devices were placed on cultured odontoblast-like cells (MDPC-23) or human dental pulp cells (HDPCs). The following groups were formed: G1 - no treatment (control); G2 to G4 - 35% H2O2, 3 x 15, 1 x 15, and 1 x 5 min, respectively; and G5 to G7 - 17.5% H2O2, 3 x 15, 1 x 15, and 1 x 5 min, respectively. Cell viability and morphology were evaluated immediately after bleaching (T1) and 72 h thereafter (T2). Oxidative stress and cell membrane damage were also assessed (T1). The amount of H2O2 in culture medium was quantified (Mann-Whitney; alpha = 5%) and colour change (DE) of enamel was analysed after 3 sessions (Tukey's test; a = 5%). Results: Cell viability reduction, H2O2 diffusion, cell morphology alteration, oxidative stress, and cell membrane damage occurred in a concentration-/time-dependent fashion. The cell viability reduction was significant in all groups for HDPCs and only for G2, G3, and G5 in MDPC-23 cells compared with G1. Significant cell viability and morphology recovery were observed in all groups at T2, except for G2 in HDPCs. The highest DE value was found in G2. However, all groups presented significant DE increases compared with G1. Conclusion: Shortening the contact time of a 35%-H2O2 gel for 5 min, or reducing its concentration to 17.5% and applying it for 45, 15, or 5 min produce gradual tooth colour change associated with reduced trans-enamel and trans-dentinal cytotoxicity to pulp cells. Clinical significance: The experimental protocols tested in the present study provided significant tooth-bleaching improvement associated with decreased toxicity to pulp cells, which may be an interesting alternative to be tested in clinical situations intended to reduce tooth sensitivity and pulp damage. (C) 2013 Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 11/12938-8 - Novos parâmetros para o clareamento dental: avaliação da eficácia, citotoxicidade e efeitos moleculares
• Beneficiário: Carlos Alberto de Souza Costa
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 11/09385-7 - Novos parâmetros para o clareamento dental: avaliação da eficácia, citotoxicidade e efeitos moleculares
• Beneficiário: Diana Gabriela Soares dos Passos
• Modalidade de apoio: Bolsas no Brasil - Doutorado