RESUMO
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.
