This study aims to investigate the role of the thioredoxin system in the development and progression of periodontitis. Researchers will examine the levels of specific antioxidant markers, such as thioredoxin reductase 1 (TrxR1), glutathione (GSH), and malondialdehyde (MDA), in gingival tissue samples collected from healthy individuals and patients with different stages of periodontal disease. The goal is to determine if TrxR1 levels can serve as a potential biomarker for diagnosing the severity and activity of periodontitis.