A carregar...
Publicação
Citotoxicidade do peróxido de hidrogénio: estudos do comportamento celular numa linhagem de células osteoblásticas fetais humanas condicionalmente imortalizadas
| Nome: | Descrição: | Tamanho: | Formato: | |
|---|---|---|---|---|
| 796.92 KB | Adobe PDF |
Autores
Resumo(s)
Objetivos: Avaliar se peróxido de hidrogénio (PH) resultante da difusão radicular proveniente de técnicas de branqueamento interno é citotóxico uma linhagem de células osteoblásticas. E se a citotoxicidade aumenta em função da concentração e do tempo de exposição. Materiais e Métodos: As células osteoblásticas (hFOB 1.19) foram cultivadas em placas de 96-poços de cultura, com uma densidade celular de 1,0 x104 células/poço, incubadas a 37ºC, humidade relativa de 95% e CO2 a 5%. No primeiro estudo, as células foram expostas ao PH em concentrações entre 0,0 e 15,0 μg/ml por um período de 1 hora, 24 e 72 horas. No segundo estudo, as células foram expostas pelo mesmo período de tempo, em concentrações entre 0,0 e 1,5 μg/ml. Ao fim do tempo de incubação avaliou-se viabilidade celular através de um kit baseado na redução da rezasurina. Os valores foram medidos por fluorescência. Captou-se imagens representativas das culturas através do microscopia invertida com óptica de contraste de fase. Resultados: No primeiro estudo, ao fim de 1 hora de exposição ao PH, a viabilidade diminuiu entre 49,46 e 72,71 % (p<0,005). Após 24horas de exposição, registou-se uma diminuição entre 76,42 e 79,04 % (p<0,005) atingindo o mínimo às 72 horas, em que a viabilidade tem um decréscimo de 93,3 a 95,2% (p<0,005). No segundo estudo, após uma hora de incubação, registaram-se diminuições de viabilidade entre 55,18 e 50,15% (p<0,005) enquanto que às 24 horas de exposição observou-se um decréscimo de viabilidade entre 62,02 e 64,89%. Às 72 horas, o decréscimo de viabilidade situou-se entre 39,25 e 41,21% (p<0,005) comparativamente com o controlo não tratado com H2O2. Conclusão: A exposição ao peróxido de hidrogénio nas concentrações testadas diminui significativamente a viabilidade celular das células osteoblásticas. No entanto, não podemos correlacionar diretamente esse decréscimo com o tempo de exposição. Serão necessários estudos complementares para confirmar as observações deste trabalho.
Objectives: To evaluate whether hydrogen peroxide resulting from root diffusion during internal bleaching techniques is cytotoxic for a cell line of conditionally immortalized human fetal osteoblasts (hFOB 1.19) and if cytotoxicity is associated with the concentration and exposure time. Materials and Methods: Osteoblast cells (hFOB1.19) were cultured in 96-well culture with a cell density of 1.0 x104 cells / well and incubated at 37 ° C, with a relative humidity of 95% and 5% CO2. In a first study, the cells were exposed to hydrogen peroxide (PH) solutions with concentrations ranging between 0.0 μg / ml and 15.0 μg / ml for a period of 1 hour, 24 and 72 hours. In the second study, the cells were exposed during the same time points to H2O2 concentrations ranging between 0.0 μg / ml and 1,5 μg / ml. At the end of incubation time, cell viability was assessed using a rezasurin-based kit and measured using a fluorometer. Results: In the pilot study, after 1 hour of exposure to PH, cell viability decreased between 49.46 and 72.71% (p <0.005). While at the 24 hours, there was a decrease between 76.42 and 79.04% (p <0.005) reaching a minimum at 72 hours when cell viability decreased from 93.3 to 95.2% (p <0.005). In the second study, it was observed that after 1-hour incubation, viability decreased between 55.18 and 50.15% (p <0.005), while after 24 hours of exposure those decreases ranged between 62.02 and 64.89 %. At 72 hours the decrease in viability was between 39.25 and 41.21% (p <0.005) compared to the untreated controls. Conclusion: PH in the range of concentrations potentially diffusing through the periodontal space after internal bleaching decreases cell viability of osteoblast cells. However, we cannot directly correlate this decrease with duration of exposure. Therefore, further studies are necessary to confirm these findings.
Objectives: To evaluate whether hydrogen peroxide resulting from root diffusion during internal bleaching techniques is cytotoxic for a cell line of conditionally immortalized human fetal osteoblasts (hFOB 1.19) and if cytotoxicity is associated with the concentration and exposure time. Materials and Methods: Osteoblast cells (hFOB1.19) were cultured in 96-well culture with a cell density of 1.0 x104 cells / well and incubated at 37 ° C, with a relative humidity of 95% and 5% CO2. In a first study, the cells were exposed to hydrogen peroxide (PH) solutions with concentrations ranging between 0.0 μg / ml and 15.0 μg / ml for a period of 1 hour, 24 and 72 hours. In the second study, the cells were exposed during the same time points to H2O2 concentrations ranging between 0.0 μg / ml and 1,5 μg / ml. At the end of incubation time, cell viability was assessed using a rezasurin-based kit and measured using a fluorometer. Results: In the pilot study, after 1 hour of exposure to PH, cell viability decreased between 49.46 and 72.71% (p <0.005). While at the 24 hours, there was a decrease between 76.42 and 79.04% (p <0.005) reaching a minimum at 72 hours when cell viability decreased from 93.3 to 95.2% (p <0.005). In the second study, it was observed that after 1-hour incubation, viability decreased between 55.18 and 50.15% (p <0.005), while after 24 hours of exposure those decreases ranged between 62.02 and 64.89 %. At 72 hours the decrease in viability was between 39.25 and 41.21% (p <0.005) compared to the untreated controls. Conclusion: PH in the range of concentrations potentially diffusing through the periodontal space after internal bleaching decreases cell viability of osteoblast cells. However, we cannot directly correlate this decrease with duration of exposure. Therefore, further studies are necessary to confirm these findings.
Descrição
Tese de mestrado, Medicina Dentária, Universidade de Lisboa, Faculdade de Medicina Dentária, 2016
Palavras-chave
Branqueamento dentário Peróxido de hidrogénio Teses de mestrado - 2016