Efeito do laser de baixa intensidade sobre células odontoblastóides in vitro e complexo dentino-pulpar in vivo
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Data
2011-03-28
Autores
Oliveira, Camila Fávero de [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
O laser de baixa intensidade (LBI) tem sido amplamente utilizado no tratamento da hipersensibilidade dentinária. Pesquisas in vivo demonstraram que o LBI pode promover um aumento na síntese de matriz de dentina e menor grau de inflamação pulpar. Entretanto, o mecanismo que rege este processo permanece desconhecido. Assim, o objetivo desta pesquisa foi avaliar o metabolismo de células odontoblastóides em cultura quando submetidas à irradiação direta ou transdentinária (indireta) com LBI e seus efeitos sobre o complexo dentino-pulpar. Células odontoblastóides MDPC-23 foram cultivadas em placas de acrílico de 24 compartimentos ou sobre a superfície pulpar de discos de dentina, com 0,4 mm de espessura e obtidos de terceiros molares, adaptados em câmaras pulpares artificiais. As células foram irradiadas diretamente por 3 vezes (a cada 24 horas) com 2, 4, 10, 15 ou 25 J/cm2 e submetidas a avaliação de metabolismo (MTT), síntese de proteína total e de fosfatase alcalina. Os dois melhores parâmetros de irradiação direta foram utilizados para o ensaio de irradiação transdentinária (indireta) das células. Como resultado da etapa direta de irradiação, foi demonstrado que tanto os valores do MTT quanto os níveis de proteína total e fosfatase alcalina apresentaram valores estatisticamente superiores nas doses de 15 e 25 J/cm2 (Mann-Whitney p<0.05). Assim, estas doses foram usadas no teste de irradiação indireta, obtendo-se aumento do metabolismo, síntese de proteína e fosfatase alcalina estatisticamente superior apenas para a dose de 25 J/cm2 (Mann-Whitney p<0.05). Desta maneira, foi possível concluir, dentro das condições experimentais, que os maiores valores de bio-estimulação das células MDPC-23 ocorreram quando estas foram irradiadas com 25 J/cm2. Para avaliação dos efeitos do LBI sobre o complexo dentinopulpar, foram confeccionadas cavidades...
Low level laser (LLL) has been widely used for treatment of dentin hypersensitivity. In vivo studies have shown increased synthesis of dentin matrix and less severe pulpal inflammation in teeth irradiated with LLL. However, the mechanisms that guide this process remain unknown. This study evaluated the metabolism of cultured odontoblastlike cells submitted to direct or transdentinal LLL irradiation as well as its effects on pulp tissue of first molars of rats. The odontoblast-like cells MDPC-23 were cultured (12,500 cells/cm2) on either 24-well acrylic plates or the pulpal surface of dentin discs adapted to artificial pulp chambers. In the first experiment, the cells received direct irradiation for 3 times (every 24 hours) with the following energy doses: 2 J/cm2, 4 J/cm2, 10 J/cm2, 15 J/cm2, and 25J/cm2. Then, the irradiated cells were evaluated concerning their metabolism, synthesis of total protein (TP) and alkaline phosphatase (ALP). The two best direct irradiation parameters obtained in this first protocol were selected to be used in the second experiment, in which the MDPC-23 cells were irradiated through 0.4mm dentin discs obtained from human teeth (indirect irradiation). For the direct assay, the MTT values as well as the TP and ALP levels were significantly higher at the doses of 15 and 25 J/cm2 (Mann-Whitney; p<0.05). When both of these energy doses were used for the indirect irradiation assay, it was observed a statistically significant increase in cell metabolism and synthesis of TP and ALP only for 25 J/cm2 (Mann-Whitney; p <0.05). Under the experimental conditions, it may be concluded that the highest biostimulation values were obtained when the MDPC-23 cells were irradiated with 25 J/cm2. For evaluation of the effects of LLL on the pulp dentin complex, class I cavities were prepared in the first superior molars of rats. After this, the cavities were immediately irradiated... (Complete abstract click electronic access below)
Low level laser (LLL) has been widely used for treatment of dentin hypersensitivity. In vivo studies have shown increased synthesis of dentin matrix and less severe pulpal inflammation in teeth irradiated with LLL. However, the mechanisms that guide this process remain unknown. This study evaluated the metabolism of cultured odontoblastlike cells submitted to direct or transdentinal LLL irradiation as well as its effects on pulp tissue of first molars of rats. The odontoblast-like cells MDPC-23 were cultured (12,500 cells/cm2) on either 24-well acrylic plates or the pulpal surface of dentin discs adapted to artificial pulp chambers. In the first experiment, the cells received direct irradiation for 3 times (every 24 hours) with the following energy doses: 2 J/cm2, 4 J/cm2, 10 J/cm2, 15 J/cm2, and 25J/cm2. Then, the irradiated cells were evaluated concerning their metabolism, synthesis of total protein (TP) and alkaline phosphatase (ALP). The two best direct irradiation parameters obtained in this first protocol were selected to be used in the second experiment, in which the MDPC-23 cells were irradiated through 0.4mm dentin discs obtained from human teeth (indirect irradiation). For the direct assay, the MTT values as well as the TP and ALP levels were significantly higher at the doses of 15 and 25 J/cm2 (Mann-Whitney; p<0.05). When both of these energy doses were used for the indirect irradiation assay, it was observed a statistically significant increase in cell metabolism and synthesis of TP and ALP only for 25 J/cm2 (Mann-Whitney; p <0.05). Under the experimental conditions, it may be concluded that the highest biostimulation values were obtained when the MDPC-23 cells were irradiated with 25 J/cm2. For evaluation of the effects of LLL on the pulp dentin complex, class I cavities were prepared in the first superior molars of rats. After this, the cavities were immediately irradiated... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Fototerapia, Odontoblastos, Lasers, Polpa, Phototherapy, Odontoblast, Fototerapia, Lasers, Pulp
Como citar
OLIVEIRA, Camila Fávero de. Efeito do laser de baixa intensidade sobre células odontoblastóides in vitro e complexo dentino-pulpar in vivo. 2011. 146 f. Tese (doutorado) - Universidade Estadual Paulista, Faculdade de Odontologia de Araraquara, 2011.