Effect of Fluoride-Treated Enamel on Indirect Cytotoxicity of a 16% Carbamide Peroxide Bleaching Gel to Pulp Cells

Autor(es)

Diana Gabriela Soares ^[1] ; Ana Paula Dias Ribeiro ^[2] ; Adriano Fonseca Lima ^[3] ; Nancy Tomoko Sacono ^[4] ; Josimeri Hebling ^[5] ; Carlos Alberto de Souza Costa ^[6]

Afiliação do(s) autor(es)

^[1] UNESP - Univ Estadual Paulista. Araraquara Dental School. Department of Dental Materials and Prosthodontics - Brasil

^[2] UnB - Federal University of Brasília. Department of Dentistry - Brasil

^[3] UNICAMP - University of Campinas. Piracicaba Dental School. Department of Restorative Dentistry - Brasil

^[4] UFG - Federal University of Goiás. Department of Dentistry - Brasil

^[5] UNESP - Univ Estadual Paulista. Araraquara Dental School. Department of Orthodontics and Pediatric Dentistry - Brasil

^[6] UNESP - Univ Estadual Paulista. Araraquara Dental School. Department of Physiology and Pathology - Brasil

• Tipo de documento: Artigo Científico
• Fonte: Brazilian Dental Journal; v. 24, n. 2, p. 121-127, 2013-04-00.

Resumo

The aim of this study was to evaluate the possibility of fluoride solutions applied to enamel to protect pulp cells against the trans-enamel and transdentinal cytotoxicity of a 16% carbamide peroxide (CP) bleaching gel. The CP gel was applied to enamel/dentin discs adapted to aicial pulp chambers (8 h/day) during 1, 7 or 14 days, followed by fluoride (0.05% or 0.2%) application for 1 min. The extracts (culture medium in contact with dentin) were applied to MDPC-23 cells for 1 h, and cell metabolism (MTT assay), alkaline phosphatase (ALP) activity and cell membrane damage (flow cytometry) were analyzed. Knoop microhardness of enamel was also evaluated. Data were analyzed statistically by ANOVA and Kruskal-Wallis tests (α=0.05). For the MTT assay and ALP activity, significant reductions between the control and the bleached groups were observed (p<0.05). No statistically significant difference occurred among bleached groups (p>0.05), regardless of fluoride application or treatment days. Flow cytometry analysis demonstrated 30% of cell membrane damage in all bleached groups. After 14 days of treatment, the fluoride-treated enamel presented significantly higher microhardness values than the bleached-only group (p<0.05). It was concluded that, regardless of the increase in enamel hardness due to the application of fluoride solutions, the treated enamel surface did not prevent the toxic effects caused by the 16% CP gel to odontoblast-like cells. (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