Influence of Intracanal Medications on th1 and th2-type Cytokine

Objectives: This clinical study assessed the influence of different intracanal medications on Th1 and Th2-type cytokine responses in apical periodontitis disease and monitored the levels of bacteria from primarily infection during endodontic procedures.
Methods: Thirty primarily infected teeth were randomly divided into 3 groups according to the medication selected: CHX, 2% CHX-gel; Ca(OH)2/SSL, Ca(OH)₂ + SSL; and Ca(OH)₂/CHX, Ca(OH)2 + 2% CHX-gel (all, n=10). Bacterial sample was collected from root canals, and the interstitial fluid sampled from lesions. Culture techniques were used to determine bacterial counts (CFU/mL). Th1 (TNF-α, INF-γ and IL-2) and Th2 cytokines (IL-4, -5, -13) were measured by ELISA-assay.
Results: All intracanal medications protocols were effective in reducing the bacterial load from root canals (all, p<0.05) and lowering the levels of Th1-type cytokines in apical lesions (all p<0.05), with no differences between them (p>0.05). Both Ca(OH)₂ treatment-protocols significantly increased the levels of Th2-type cytokines (p<0.05), with no differences between them (p>0.05). Thus, CHX medication showed the lowest effectiveness in increasing the levels of Th2-cytokine type. After treatment, regardless the type of medication, the linear regression analysis indicated the down-regulation of Th2-type cytokines by Th1-type one.
Conclusions: All intracanal medication protocols were effective in reducing bacterial load and lowering the levels of Th1-type cytokines. Thus, the use of Ca(OH)₂ medications contributed to the increase in the Th2-type cytokine response in apical periodontitis.