The dysregulation of the transforming growth factor-beta signaling pathway can lead to inflammation and tissue destruction in the pathogenesis of periodontitis. This study aims to evaluate the levels of GDF-15, Smad 2, Smad 5, Smad 6, and IL-6 in gingival crevicular fluid (GCF) and saliva between individuals with periodontitis and periodontal healthy controls and to evaluate the relationship of these biomarkers with clinical periodontal parameters. This study aims to investigate the levels of GDF-15, Smad2, Smad5, Smad6, and IL-6 in GCF and saliva samples from individuals with periodontitis and periodontally healthy controls, as well as to assess the associations of these biomarkers with clinical periodontal parameters. A total of 44 systemically healthy individuals, including 22 patients diagnosed with stage III/grade B periodontitis and 22 periodontal healthy individuals, were included in the study. Clinical periodontal parameters (plaque index (PI), probing depth (PD), clinical attachment level (CAL), and bleeding on probing (BOP)) were recorded. GDF-15, Smad 2, Smad 5, Smad 6, and IL-6 levels in saliva and GCF were analyzed using the ELISA method.

Inclusion Criteria:

• being over 18 years of age;
• having at least 20 natural teeth excluding third molars;
• being systemically healthy

Exclusion Criteria:

• under 18 years of age;
• had used antibiotics
• had used nonsteroidal anti-inflammatory drugs, corticosteroids, immunosuppressants, beta-blockers, calcium channel blockers, anticoagulants, or hormonal contraceptives within the past 6 months;
• had systemic diseases such as diabetes mellitus, rheumatoid arthritis, cardiovascular diseases, epilepsy, renal or hepatic disorders, or viral infections like HIV/AIDS;
• pregnant or breastfeeding;
• current smokers or had a history of alcoholism;
• had received nonsurgical periodontal therapy within the last 6 months or surgical periodontal treatment within the last 12 months;
• had fewer than 20 natural teeth (excluding third molars);
• had fixed orthodontic appliances.

The study population comprised individuals who presented to the Department of Periodontology at Istanbul Medipol University between April and October 2023 for dental consultation or treatment.