IL-1β and S1P Levels After Periodontal Therapy: A Split-Mouth Study

Diseased sites were selected based on the most severe clinical findings, including probing depth (PD) of ≥6 mm, clinical attachment level (CAL) of ≥5 mm, and the presence of bleeding on probing (BOP). Healthy sites were defined by PD ≤3 mm, no clinical attachment loss, absence of radiographic bone loss, and BOP negativity. All selected sites were non-adjacent and distributed throughout the oral cavity to reduce regional bias. This study also aimed to explore site-specific changes in biomarker expression over time and assess the correlation between GCF IL-1β/S1P levels and clinical indicators of periodontal disease severity and healing response. All GCF sampling was repeated from the same sites at each time point. Control (healthy) site sampling was done at baseline and 3 months, while diseased site sampling was conducted at baseline, 1 month, and 3 months.