Cytokine expression of IL‐8 before and after root canal treatment in patients with symptomatic apical periodontitis: A clinical trial.

This study's objective was to compare the cytokine expression of IL‐8 in periapical tissues of single‐rooted teeth with symptomatic apical periodontitis (SAP) before and after root canal treatments. As well as, comparing IL‐8 levels in peri‐apical tissues between vital and necrotic teeth with SAP. Methodology: Thirty‐six patients were allocated according to their pulp status into two experimental groups (n = 18) receiving the same treatment protocol; group 1: Vital pulps with SAP, and group 2: non‐vital pulps with SAP. Conventional endodontic treatment was done on two visits; isolation and disinfection of the operative field were undertaken, and two‐stage access cavity preparation was implemented. The first pre‐instrumentation peri‐apical sample (S1) was collected prior to cleaning and shaping procedures. A 2.5% NaOCl irrigation was used to thoroughly irrigate the canal after performing root canal preparation utilising the ProTaper Next (PTN) rotary system. After 1 week, the second post‐instrumentation peri‐apical sample (S2) was collected. Using an ELISA kit, the quantity of IL‐8 was evaluated following the collection of all samples. Results: In all pre‐instrumentation samples, IL‐8 was detected (100%). The level of IL‐8 expression was significantly decreased from the S1 to S2 of all samples (p < 0.001). The intra‐group comparison showed a statistically significant reduction in the level of IL‐8 expression between S1 and S2 in both vital and non‐vital groups where p < 0.001* in both groups. The inter‐group comparison of levels of IL‐8 expression (vital and non‐vital) revealed a significant difference between both groups regarding the pretreatment sample with the higher levels of IL‐8 shown in the non‐vital group (p < 0.001). While in the post‐treatment sample, both groups showed a significant reduction in the level of IL‐8 expression but the difference between them was not statistically significant (p = 0.226). Conclusion: Root canal instrumentation seems to be efficient in decreasing the levels of anti‐inflammatory cytokines, namely IL‐8. Further research should clarify how intra‐canal medicaments affect inflammatory mediator levels. [ABSTRACT FROM AUTHOR]