The Relationship Between Diabetes and Periodontal Disease

Background: Diabetes mellitus and periodontitis are both highly prevalent chronic diseases, and evidence indicates that each aggravates the other. This review summarises the relationship for clinicians in dentistry and medicine. Methods: This narrative review drew on PubMed/MEDLINE records dated 2010–2026 (English only); bibliographic details were verified in Crossref, and 29 sources were grouped by theme. Results: Cohort meta-analyses give summary relative risks of 1.26 for incident diabetes in periodontitis and 1.24 for incident periodontitis in diabetes. Proposed mechanisms include AGE–RAGE signalling, raised IL-1β, IL-6 and TNF-α, dysbiosis, impaired neutrophil function and delayed wound healing. The 2022 Cochrane review found a 0.43% HbA1c reduction 3–4 months after periodontal treatment (moderate-certainty evidence), yet the two largest trials disagreed. The 2017/2018 classification adds a grade modifier for diabetes, and joint EFP/IDF and EFP/WONCA Europe consensus reports call for dentist–physician collaboration. Conclusions: Periodontal care deserves a place in diabetes management, and reciprocal screening and referral are justified. Long-term trials and data from Central Asia are needed.