The Influence Of Enterococcus Faecalis On TNF-α Expression In Periapical Periodontitis Of Rats

Objective: To explore the expression and fuction of tumor necrosisfactor-α in rat periapical periodontitis caused by Enterococcus faecalis.Methods:24healthy male SD rats were choosen for the study. Afterthe odontotrypy on the right mandibular first molar using a small ball dentaldrill, these rats were randomly divided into A、 B Groups and each grouphad12rats. The medullary cavity of Group A were filled with PBS cottonballs while Group B were filled with Enterococcus faecalis bacteriasuspension cotton balls.Both groups were using imported glass ionomercement to fill pulp cavity. Left mandibular first molar without any treatmentwere regarded as the healthy control group. According to differentpoint-in-time(1w、2w、3w、4w）,3rats were randomly chosen to besacrificed by excess triformol, and then separated the mandible, scrape thebone tissue of the right mandibular first molar for RNA extraction. Afterreverse transcription, the Real-time PCR were used to detect the expressionof TNF-α gene of each group. The results were analysised.Results:1. Bits of TNF-α were expressed in control. After the access operation,the expression of TNF-α in Group A、 B were increased compared withcontrol. The differences between other groups have statistically significant(P<0.05). 2. Group A: after the access operation, from1w to2w, the expressionof TNF-α were increased gradually and reached a peak at2w, then3wdecline (P<0.05). The expression of TNF-α continues to decline in4w.3. Group B: after the access operation, from1w to2w, the expressionof TNF-α were increased gradually and reached a peak at2w (P<0.05).From2w to4w, the expression of TNF-α decline (P<0.05).4. The expression of TNF-α in B group were more than that in A groupin1w、2w、3w, and the expression of TNF-α in A group were more than thatin B group in4w (P<0.05).Conclusion:1. Periapical Periodontitis was closely related to the expression ofTNF-α mRNA, which reminded that TNF-α involved in inflammation andbone resorption of Periapical Periodontitis.2. TNF-α was bound up with Periapical Periodontitis induced ofEnterococcus faecalis, which reminded that TNF-α probably aggravatedinflammation and bone resorption of Periapical Periodontitis.