Salivary Apelin, Chemerin, Ghrelin, and Lipocalin-2 Levels in Diabetic Patients With Periodontitis

Inclusion Criteria: * Individuals aged 18 to 80 years. Individuals who apply to the Department of Periodontology, Faculty of Dentistry, Necmettin Erbakan University. Individuals who agree to participate in the study and sign the informed consent form. Presence of at least 20 teeth. For the periodontally healthy groups: diagnosis of periodontal health based on routine clinical and radiographic examination. For the periodontitis groups: diagnosis of generalized Stage II or Stage III periodontitis based on routine clinical and radiographic examination according to the 2017 World Workshop Classification of Periodontal and Peri-Implant Diseases and Conditions. For the type 2 diabetes mellitus groups: diagnosis of type 2 diabetes mellitus. For the systemically healthy groups: absence of systemic diseases, including type 2 diabetes mellitus. Exclusion Criteria: * Periodontal treatment, including scaling and root surface debridement, within the last 6 months. Antibiotic use within the last 6 months. Pregnancy or lactation. Presence of autoimmune diseases such as rheumatoid arthritis, familial Mediterranean fever, ankylosing spondylitis, Behçet disease, or psoriasis. Presence of systemic diseases other than type 2 diabetes mellitus in the diabetes groups. Presence of systemic diseases such as nephrotic syndrome, chronic renal disease, or cardiovascular disease. Smoking 10 or more cigarettes per day.