Diabetes mellitus and periodontitis are two widespread long-term diseases that influence one another and have major consequences for global health. Periodontitis—an inflammatory gum disorder triggered by microbial imbalance—can make blood sugar regulation harder in diabetic patients, while poorly managed diabetes increases the severity of periodontal tissue destruction. This interaction forms a harmful loop, where immune disruption, infection, and inflammation constantly worsen both diseases and affect systemic health. The underlying biological links include persistent inflammation, immune irregularities, and microbial instability, creating an ongoing inflammatory process that extends beyond the mouth. Because of this connection, treating one disorder can positively affect the other. Evidence indicates that periodontal care can help improve glycemic balance in diabetic individuals, highlighting the value of joint management approaches. This review emphasizes the necessity of understanding the molecular and immune-based pathways behind this connection to create unified treatments that could substantially enhance patient well-being.
