The Impact of Diabetes Mellitus on Apical Periodontitis: Insights from Animal and Human Studies

Objective: This review examines the interrelation between diabetes mellitus (DM) and apical periodontitis (AP), explaining key biological mechanisms and summarizing the main findings from animal and human studies. Methods and Results:A comprehensive literature search was conducted across PubMed, Scopus, and Web of Science, focusing on peer-reviewed studies published over the last two decades.Several studies have shown that hyperglycemia impairs VEGFregulated angiogenesis, reduces osteoblast activity, and maintains elevated levels of inflammatory cytokines such as TNF-α and IL-6, thereby increasing periradicular lesion size and delaying tissue healing.Diabetic animal models showed reduced bone density, increased vascular calcification, and accelerated progression from caries to pulp necrosis.Clinically, T2DM (type 2 diabetes mellitus) was associated with higher AP prevalence, greater bacterial endotoxin load, and lower root-canal success rates.These effects were magnified by poor glycemic control.Conclusion: Diabetes mellitus exacerbates AP through impaired angiogenesis, dysregulated immune response, and impaired bone metabolism.To reduce these risks, strategies such as strict blood glucose control, enhanced antimicrobial disinfection, minimally invasive interventions, and the use of bioactive materials are recommended.Future research should explore how controlling oral infections impacts systemic metabolic health.Investigating the role of bioactive materials and anti-inflammatory treatments in improving AP outcomes is also essential.(InternationalJournal of Biomedicine.2026;16(1):6-13.)