Citotoxicidade trans-amelodentinária e alterações estruturais no esmalte após clareamento com géis caseiros a base de peróxido da carbamida
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Data
2010-11-16
Autores
Soares, Diana Gabriela de Sousa [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
No clareamento dental caseiro são utilizados géis clareadores contendo baixas concentrações de peróxido de carbamida (PC). Entretanto, o componente ativo responsável pelo clareamento é o peróxido de hidrogênio (H2O2), o qual pode se difundir através do esmalte e dentina e causar efeitos tóxicos sobre células pulpares. Portanto, o objetivo deste trabalho foi avaliar a citotoxicidade trans-amelodentinária de géis clareadores à base de PC sobre células odontoblastóides MDPC- 23 após diferentes tempos de contato dos produtos com o esmalte, bem como o efeito do clareamento na estrutura dental. Para avaliação da citotoxicidade, discos de esmalte/dentina obtidos de incisivos bovinos foram adaptados em câmaras pulpares artificiais. Géis clareadores com 10% ou 16% de PC foram aplicados por 8 horas diárias sobre a superfície de esmalte pelos períodos de 1, 7 ou 14 dias. Os extratos (meio de cultura + produtos do gel clareador que se difundiram através do esmalte/dentina) foram aplicados por 1 hora sobre as células em cultura, sendo realizada avaliação do metabolismo celular pelo teste do MTT (α=5%; Anova um critério e teste de Tukey), e da morfologia celular por MEV. Para avaliação das alterações estruturais do esmalte, foi realizada mensuração da microdureza Knoop (α=5%; Anova dois critérios e teste de Tukey) em blocos de esmalte (50g/15s) antes do clareamento e nos períodos de 1, 7 e 14 dias, bem como avaliação da morfologia superficial por MEV. Os resultados não demonstraram diferença significante para o metabolismo celular entre o grupo controle e nos grupos onde foi aplicado o gel com PC a 10% (p>0.05). Já para os grupos clareados com 16% de PC, foi observado diferença significante nos períodos de 1, 7 e 14 dias quando comparados ao grupo controle (p<0.05). Não houve diferença significante quando se comparou os grupos 10% e 16% de PC em todos...
The home bleaching technique uses gels with low concentrations of carbamide peroxide (CP). However, the hydrogen peroxide is the active component and can difuse by enamel and dentine to cause toxic effects on pulp cells. The purpose of this study was to evaluate the trans-enamel and transdentinal cytotoxicity of bleaching gels based on carbamide peroxide (CP) on odontoblast-like cells after different contact times of the products with enamel, and the effects of bleaching on the tooth structure. To analyze the citotoxicity, enamel/dentine discs were obtained from bovine incisors and placed in artificial pulp chambers. Bleaching gels containing 10% or 16% CP were applied for 8 hours/day on the enamel side of the discs during periods of 1, 7 or 14 days. The extracts (culture medium plus bleaching gel products that diffused through the discs) were collected and applied on previously cultured MDPC-23 cells for 1 hour. Cell metabolism was evaluated by the MTT assay (α=0.05; one-way ANOVA and Tukey’s test), and the cell morphology was analysed by SEM. To evaluate the structural changes on the enamel, the Knoop microhardness was analized (α=0.05; two-way ANOVA and Tukey’s test) on enamel blocks (50g/15s) before and after 1, 7 and 14 applications of bleaching agent, and the morphological surface was analized by SEM. There were no significant difference (p>0.05) for cell metabolism between the controls and the groups bleached with 10% CP gel. In the groups bleached with 16% CP gel, however, cell metabolism decreased significantly (p<0.05) at 1, 7 and 14 days. There was no significant difference (p>0.05) among 1, 7 or 14 applications of the gels for either of the CP concentrations. The microhardness for the groups bleached with 10% CP gel have difference with the control group after 7 and 14 applications. For the groups bleached with 16% of CP, significant difference was observed in all periods... (Complete abstract click electronic access below)
The home bleaching technique uses gels with low concentrations of carbamide peroxide (CP). However, the hydrogen peroxide is the active component and can difuse by enamel and dentine to cause toxic effects on pulp cells. The purpose of this study was to evaluate the trans-enamel and transdentinal cytotoxicity of bleaching gels based on carbamide peroxide (CP) on odontoblast-like cells after different contact times of the products with enamel, and the effects of bleaching on the tooth structure. To analyze the citotoxicity, enamel/dentine discs were obtained from bovine incisors and placed in artificial pulp chambers. Bleaching gels containing 10% or 16% CP were applied for 8 hours/day on the enamel side of the discs during periods of 1, 7 or 14 days. The extracts (culture medium plus bleaching gel products that diffused through the discs) were collected and applied on previously cultured MDPC-23 cells for 1 hour. Cell metabolism was evaluated by the MTT assay (α=0.05; one-way ANOVA and Tukey’s test), and the cell morphology was analysed by SEM. To evaluate the structural changes on the enamel, the Knoop microhardness was analized (α=0.05; two-way ANOVA and Tukey’s test) on enamel blocks (50g/15s) before and after 1, 7 and 14 applications of bleaching agent, and the morphological surface was analized by SEM. There were no significant difference (p>0.05) for cell metabolism between the controls and the groups bleached with 10% CP gel. In the groups bleached with 16% CP gel, however, cell metabolism decreased significantly (p<0.05) at 1, 7 and 14 days. There was no significant difference (p>0.05) among 1, 7 or 14 applications of the gels for either of the CP concentrations. The microhardness for the groups bleached with 10% CP gel have difference with the control group after 7 and 14 applications. For the groups bleached with 16% of CP, significant difference was observed in all periods... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Toxicidade, Clareamento dental, Odontoblastos, Esmalte dentário, Toxicity, Tooth bleaching, Odontoblasts, Dental enamel
Como citar
SOARES, Diana Gabriela de Sousa. Citotoxicidade trans-amelodentinária e alterações estruturais no esmalte após clareamento com géis caseiros a base de peróxido da carbamida. 2010. 115 f. Dissertação (mestrado) - Universidade Estadual Paulista, Faculdade de Odontologia de Araraquara, 2010.