Effect of nonsurgical periodontal treatment on NLRP3, Nrf2, Caspase-1, interleukin-1B, interleukin-18 in gingival crevicular fluid of severe periodontitis.

Objectives: The signaling pathways activated in periodontitis is important to treat or to prevent the disease. Recent data have established the role of inflammasomes in periodontitis. The purpose of this study was to determine the concentrations of NLRP3, IL-1β, IL-18, Caspase-1, and Nrf2 in gingival-crevicular-fluid (GCF) from patients with Stage3 periodontitis following nonsurgical-periodontal-treatment (NSPT), to compare them with clinical periodontal parameters, and to evaluate these parameters as potential biomarkers of response to NSPT.

Methods: A total of 129 individuals (Healthy, n:64; periodontitis, n:65) involved in the study. GCF was collected from the distal and mesial regions of 5 single-rooted anterior teeth and clinical periodontal parameters [plaque index(PI), bleeding-on-probing(BOP), probing-pocket-depth(PPD) and clinical-attachment-loss(CAL)] were obtained before and 6 month after NSPT. Levels of biochemical parameters (NLRP3, IL-18, IL-1β, Caspase-1 and Nrf2) were evaluated in GCF samples by ELISA.

Results: All biochemical and clinical periodontal parameters decreased significantly in the periodontitis group after NSPT (P < 0.001). Except for PI, IL-1β and IL-18, all parameters were significantly higher in the Post-Treatment groups compared to the Healthy group (P < 0.001). IL-1β and IL-18 reached healthy levels with 6-month follow-up of NSPT. All biochemical parameters were significantly correlated with full-mouth clinical periodontal parameters in the Pre-Treatment and Post-Treatment groups (P < 0.01).

Conclusion: The tested biochemical parameters play important roles in the pathogenesis of periodontitis. IL-1β and IL-18 support their potential as clinically important biomarkers for treatment monitoring. Elevated levels of NLRP3, Caspase-1, and Nrf2 may indicate ongoing inflammatory activity rather than complete resolution after treatment. Clinical applicability must be confirmed by larger, longitudinal studies using advanced molecular techniques.

Clinical relevance: Monitoring the decrease of IL-1β and IL-18 with NSPT in GCF samples may indicate that these markers are promising treatment follow-up biomarkers.