Diabetes Mellitus and Periodontal Disease: A Bidirectional Relationship and Its Clinical Implications

Diabetes mellitus and periodontitis are two highly prevalent chronic non-communicable diseases whose relationship is bidirectional. Chronic hyperglycemia promotes the accumulation of advanced glycation end products, oxidative stress, impaired neutrophil function and an exaggerated inflammatory response, which together accelerate the destruction of periodontal tissues. In turn, severe periodontitis maintains a state of low-grade systemic inflammation that may worsen insulin resistance and impair glycemic control. Current evidence indicates that non-surgical periodontal therapy can produce a modest improvement in glycated hemoglobin (HbA1c) in people with diabetes, although the effect size varies between trials. This review summarizes the epidemiological data, pathogenic mechanisms and clinical manifestations linking diabetes and periodontal disease and outlines evidence-based preventive and therapeutic strategies, emphasizing close cooperation between dentists, endocrinologists and primary care physicians.