Andreea Marica, Mihaela Moisa, Simona Cavalu, Florin Bănică
Introduction/Objective This study aims to map twenty-five years of global scientific output and thematic evolution of the relationship between Diabetes Mellitus (DM) and Apical Periodontitis (AP) from 2000 to 2025. Methods Bibliometric data were extracted from the Web of Science Core Collection using VOSviewer to perform network visualization and quantitative mapping of publication trajectories, country/institutional co-authorship networks, and keyword co-occurrences. Results Publication output grew in three phases: incipient 2000–2010, steady growth 2011–2019, and rapid expansion after 2020, peaking in 2023. The United States and Brazil emerged as the most productive nations; a dominant Ibero-American research network is led by the University of Sevilla and São Paulo State University. Keyword clustering clearly shows the interdisciplinary nature of research connecting endodontic pathology, clinical treatment, and systemic disease. Specialized endodontic journals served as the primary publishing platforms, while highly cited papers focused on mechanisms driving a bidirectional link between DM and AP. Discussion The bibliometric data reflect the evolutionary trajectory from epidemiologic association toward mechanistic exploration and systemic integration. The mapping analysis highlights the importance of separating AP from marginal periodontal disease. The current literature is limited by diagnostic heterogeneity, incomplete reporting of diabetes duration, and the influence of confounding variables. Conclusion The DM–AP research domain has matured into a distinct, well-consolidated specialty within endodontic medicine. By mapping the publication timelines, dominant themes and current limitations, this study provides a reliable foundation for designing future, more rigorous clinical research. Future research must prioritize standardized diagnostic frameworks, uniform metabolic cut-offs and prospective longitudinal trials.