IADR Abstract Archives
Cellular Responses Induced by 10% Carbamide Peroxide in Odontoblast-Like Cells
Objectives: To evaluate the cellular response to exposure to 10% carbamide peroxide (10%PC) in human odontoblast like cells (hOLC).
Methods: Enamel with their respective dentin discs from human anterior teeth were adapted to Transwell inserts in a 24 well plate to ensure dentin contact with the culture medium to allow diffusion of the 10%PC (Opalescence PF 10% / Ultradent) that was applied following the manufacturer's instructions (30 min/day x 20 days). The extract containing whitening agent components that diffused through the tissue was collected from each well. hOLCs (25x103 cells/well) were seeded in 96 well plates to be exposed to the collected extract for 24 h. Cell membrane integrity was determined by calcein assay and intracellular redox status with the 2',7'-dichlorofluorescein diacetate probe. The production of malondialdehyde was used as an indicator of lipid peroxidation in the cell membrane and the changes of the mitochondrial membrane potential was evaluated by the tetramethylrhodamine ester assay. Data were analyzed with the Shapiro-Wilk, ANOVA and Tukey post-hoc tests (p<0.05).
Results: A decrease in the viability of OLCs exposed to 10%PC was observed, associated with an transitory increase in intracellular reactive oxygen species, which induced lipid peroxidation and collapse of the mitochondrial membrane potential.
Conclusions: 10%PC modified the intracellular redox state, which induced decreased viability, changes in membrane permeability, and altered mitochondrial physiology. Lipid peroxidation, is probably, one of the main mechanisms involved in oxidative damage.
Methods: Enamel with their respective dentin discs from human anterior teeth were adapted to Transwell inserts in a 24 well plate to ensure dentin contact with the culture medium to allow diffusion of the 10%PC (Opalescence PF 10% / Ultradent) that was applied following the manufacturer's instructions (30 min/day x 20 days). The extract containing whitening agent components that diffused through the tissue was collected from each well. hOLCs (25x103 cells/well) were seeded in 96 well plates to be exposed to the collected extract for 24 h. Cell membrane integrity was determined by calcein assay and intracellular redox status with the 2',7'-dichlorofluorescein diacetate probe. The production of malondialdehyde was used as an indicator of lipid peroxidation in the cell membrane and the changes of the mitochondrial membrane potential was evaluated by the tetramethylrhodamine ester assay. Data were analyzed with the Shapiro-Wilk, ANOVA and Tukey post-hoc tests (p<0.05).
Results: A decrease in the viability of OLCs exposed to 10%PC was observed, associated with an transitory increase in intracellular reactive oxygen species, which induced lipid peroxidation and collapse of the mitochondrial membrane potential.
Conclusions: 10%PC modified the intracellular redox state, which induced decreased viability, changes in membrane permeability, and altered mitochondrial physiology. Lipid peroxidation, is probably, one of the main mechanisms involved in oxidative damage.