Abstract
Introduction: The incidence of diabetes mellitus (DM) in Central and South American countries was estimated at 27.4 million people and projected to reach 45 million by 2030. According to the International Diabetes Federation, there were 366 million people with the disease in 2011, with an expected number of 552 million by 2030. Periodontal disease is an inflammation (chronic or acute) that affects the supporting structures of the tooth and is influenced by certain local or systemic conditions. DM can contribute to the development of periodontal disease, reducing the quality of life. Objective: The aim was to present the main clinical evidence on the impact of periodontal diseases on metabolism, diabetes mellitus, and quality of life through a systematic review. Methods: The systematic review rules of the PRISMA Platform were followed. The search was conducted from September to October 2025 across the Web of Science, Scopus, Embase, PubMed, ScienceDirect, SciELO, and Google Scholar databases. The quality of the studies was assessed using the GRADE instrument, and the risk of bias was evaluated according to the Cochrane instrument. Results and Conclusion: According to the GRADE instrument, most studies presented homogeneity in their results, with X2=89.7%>50%. A total of 86 articles were found and submitted for eligibility analysis, with 16 final studies selected to compose the results of this systematic review. Considering the Cochrane tool for risk of bias, the overall assessment resulted in 11 studies with a high risk of bias and 24 studies that did not meet GRADE and AMSTAR2 standards. It was concluded that diabetes mellitus is a factor that aggravates periodontal disease, and affecting a high percentage of the population, it should receive special attention in the anamnesis performed by dentists, especially periodontists. The presence of bacterial plaque aggravates periodontal disease; oral health control can indeed reduce the amount of insulin needed by the patient. Periodontal treatment should be cautious and balanced, and it is fundamental that the periodontist is aware of the limitations, alterations, and disorders that the diabetic patient may present. Adults with type 2 diabetes have a high probability of developing periodontitis, and serum vitamin B6 may have a modulating effect on this association. Patients with type 2 diabetes who maintain a higher intake of vitamin B6 may experience potential benefits in reducing the risk of periodontitis.