Experimental Furcal Perforation Treated with MTA: Analysis of the Cytokine Expression.

The aim of this study was to evaluate mineral trioxide aggregate (MTA)-induced cytokine expression in mice after experimental furcal perforation. BALB/c mice (n=5) were subjected to induced furcal drilling of the maxillary first molar followed by MTA sealing in the left side (experimental group) and paraffin sealing in the right side (control group). Animals were euthanized at 7, 14 and 21 days after sealing the perforations. The expression levels of the IFN-γ, TNF-α, IL-10, IL-4, TGF-ß and RANKL genes were investigated by real time polymerase chain reaction (PCR) in the teeth and surrounding tissues. In the experimental groups, after the 7th day, there was a down-regulation of the mRNA levels of TNF-α and IL-4 compared to the 14th day (p<0.05). In these groups, the mRNA levels of RANKL, IFN-γ and TNF-α were statistically higher after 14 days compared to 21 days post-MTA sealing (p<0.05). The level of IL-10 mRNA was increased at the 21st day (p<0.05). The mRNA expression of TGF-ß did not exhibit any statistically relevant results. There was a statistical down-regulation of IL-4 gene expressions when control and experimental groups were compared at days 7 and 21. In conclusion, MTA sealing favored the expression of pro-inflammatory cytokines in the intermediate phase of the immuno-inflammatory response (14th day). The reduction of these cytokines in later phase of the response was probably due to immunoregulation by IL-10.

Experimental Furcal Perforation Treated with MTA: Analysis of the Cytokine Expression

The aim of this study was to evaluate mineral trioxide aggregate (MTA)-induced cytokine expression in mice after experimental furcal perforation. BALB/c mice (n=5) were subjected to induced furcal drilling of the maxillary first molar followed by MTA sealing in the left side (experimental group) and paraffin sealing in the right side (control group). Animals were euthanized at 7, 14 and 21 days after sealing the perforations. The expression levels of the IFN-γ, TNF-α, IL-10, IL-4, TGF-β and RANKL genes were investigated by real time polymerase chain reaction (PCR) in the teeth and surrounding tissues. In the experimental groups, after the 7th day, there was a down-regulation of the mRNA levels of TNF-α and IL-4 compared to the 14th day (p<0.05). In these groups, the mRNA levels of RANKL, IFN-γ and TNF-α were statistically higher after 14 days compared to 21 days post-MTA sealing (p<0.05). The level of IL-10 mRNA was increased at the 21st day (p<0.05). The mRNA expression of TGF-β did not exhibit any statistically relevant results. There was a statistical down-regulation of IL-4 gene expressions when control and experimental groups were compared at days 7 and 21. In conclusion, MTA sealing favored the expression of pro-inflammatory cytokines in the intermediate phase of the immuno-inflammatory response (14th day). The reduction of these cytokines in later phase of the response was probably due to immunoregulation by IL-10.

O objetivo desse artigo foi avaliar a expressão das citocinas induzidas por MTA após a perfuração experimental de furca, em camundongos. Camundongos Balb/c (n=5) foram submetidos à perfuração induzida da furca do primeiro molar superior, seguido pelo selamento da mesma com MTA no lado esquerdo (grupo experimental) e com parafina no lado direito (grupo controle). Os animais foram sacrificados 7, 14 e 21 dias após o tratamento da perfuração. A expressão gênica dos níveis de IFN-γ, TNF- α, IL-10, IL-4, TGF- β e RANKL foram investigadas por PCR em tempo real nos dentes e tecidos adjacentes. No grupo experimental, após 7 dias, houve uma diminuição da expressão dos níveis de TNF- α e IL-4 comparados ao 14° dia (p<0,05). Nesses mesmos grupos, os níveis de mRNA de RANKL, IFN- γ e TNF- α foram estatisticamente maiores após 14 dias comparados a 21 dias após o tratamento com MTA (p<0,05). Os níveis de IL-10 estavam aumentados no 21^o dia (p<0,05). A expressão de mRNA do TGF- β não apresentou alteração estatisticamente relevante. Houve uma redução estatística da expressão gênica da IL-4 quando os grupos controle e experimental foram comparados nos dias 7 e 21. Em conclusão, o selamento com MTA favoreceu a expressão de citocinas pró-inflamatórias na fase intermediária da resposta imuno-inflamatória (14^o dia). A redução dessas citocinas, na fase tardia da resposta, ocorreu provavelmente devido à imunoregulação da expressão de IL-10.