This study investigates the relationship between Type 2 diabetes mellitus (T2DM), glycemic control, and periodontal disease. Researchers analyzed the levels of inducible nitric oxide synthase (iNOS) and proinflammatory cytokines, such as tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), and interferon-gamma (IFN-γ), in 118 participants. The participants were categorized based on their periodontal and diabetes control status.

This study is an observational analysis using a cross-sectional time perspective and explores the interplay between Type 2 diabetes mellitus (T2DM), glycemic control, and periodontal disease by evaluating the expression of inducible nitric oxide synthase (iNOS) and proinflammatory mediators (TNF-α, IL-1β, IFN-γ, and PGE2) in gingival tissues. A total of 118 participants were classified into six groups based on their periodontal health and glycemic control status, determined by HbA1c levels.

Gingival biopsies were collected and analyzed using ELISA to measure biomarker levels. The study found significant differences in inflammatory marker concentrations between groups, with poorly controlled T2DM participants showing markedly higher levels of iNOS and cytokines. This aligns with the hypothesis that poor glycemic control amplifies periodontal inflammation and oxidative stress, contributing to tissue destruction.

The findings underline the critical role of glycemic regulation in managing periodontal disease and suggest potential targets, such as iNOS, for therapeutic interventions. This study adheres to ethical standards, including informed consent and approval by the Ondokuz Mayis University Clinical Research Ethics Committee. The results emphasize the bidirectional relationship between diabetes and periodontal health, contributing to a better understanding of the systemic implications of periodontal inflammation.

Inclusion Criteria:

• Participants must be between 18 and 65 years of age (according to the World Health Organization definition of young and adult individuals).
• Diagnosed with periodontitis (Stage 2, 3, or 4) based on the 2017 Classification of Periodontal Diseases and Conditions.
• Diabetes control status determined by HbA1c levels: controlled diabetes: HbA1c ≤ 7, uncontrolled diabetes: HbA1c > 7
• Must volunteer and sign an informed consent form for clinical evaluations and collection of tissue samples.

Exclusion Criteria:

• History of smoking.
• Presence of systemic or local diseases affecting the immune system (e.g., autoimmune disorders, HIV, hepatitis).
• Pregnant or breastfeeding individuals.
• History of antibiotic use or periodontal treatment within the last 3-6 months.
• History of immunosuppressive therapy or chemotherapy.
• Requirement for antibiotic prophylaxis.
• Severe systemic illnesses unrelated to diabetes (e.g., cancer, cardiovascular diseases).

Study participants will be selected from individuals seeking dental care at the Department of Periodontology, Faculty of Dentistry, Ondokuz Mayis University, Samsun, Turkey. The population includes adults with varying systemic and periodontal health statuses, such as individuals with Type 2 diabetes mellitus (T2DM) and/or periodontitis. Participants represent a diverse clinical population from the surrounding region and are recruited based on their suitability for the study's objectives.

The decision to not share individual participant data (IPD) is based on ethical considerations, institutional policies, and the need to protect participant privacy and confidentiality. The collected data will only be used for the purposes of this study and will not be made available for external use.