REVIEW ARTICLE Dental caries, diabetes mellitus, metabolic control and diabetes duration: A systematic review and meta-analysis Ana Sofia Coelho 1,2,3,4,5 | Inês Flores Amaro 1 | Francisco Caramelo 2,3,4,5,6 | Anabela Paula 1,2,3,4,5 | Carlos Miguel Marto 1,2,3,4,5,7 | Manuel Marques Ferreira 2,3,4,5,8 | Maria Filomena Botelho 2,3,4,5 | Eunice Virgínia Carrilho 1,2,3,4,5 1 Faculty of Medicine, Institute of Integrated Clinical Practice, University of Coimbra, Coimbra, Portugal 2 Faculty of Medicine, Coimbra Institute for Clinical and Biomedical Research (iCBR), University of Coimbra, Coimbra, Portugal 3 Center for Innovative Biomedicine and Biotechnology, University of Coimbra, Coimbra, Portugal 4 Faculty of Medicine, CIMAGO—Center of Investigation on Environment, Genetics and Oncobiology, University of Coimbra, Coimbra, Portugal 5 CNC.IBILI, University of Coimbra, Coimbra, Portugal 6 Faculty of Medicine, Laboratory of Biostatistics and Medical Informatics, University of Coimbra, Coimbra, Portugal 7 Faculty of Medicine, Experimental Pathology Institute, University of Coimbra, Coimbra, Portugal 8 Faculty of Medicine, Institute of Endodontics, University of Coimbra, Coimbra, Portugal Correspondence Ana Sofia Coelho, Area de Medicina Dentária—Av. Bissaya Barreto, Bloco de Celas, 3000-075 Coimbra, Portugal. Email: anasofiacoelho@gmail.com Abstract Objective: To analyze articles aimed at evaluating the association between diabetes, metabolic control, diabetes duration, and dental caries. Overview: A systematic search in PubMed, Cochrane Library, Embase, and Web of Science was conducted to retrieve papers in English, Portuguese, and Spanish, up to April 2019. The research strategy was constructed considering the “PECO” strategy. Only quantitative observational studies were analyzed. The risk of bias was assessed using the Newcastle-Ottawa Quality Assessment Scale. The meta-analyses were per- formed based on random-effects models using the statistical platform R. A total of 69 articles was included in the systematic review and 40 in the meta-analysis. Type 1 diabetics have a significantly higher DMFT compared to controls. No significant dif- ferences were found between type 2 diabetics and controls and between well- controlled and poorly controlled diabetics. Concerning diabetes duration, all authors failed to find differences between groups. Conclusion: Although there is still a need for longitudinal studies, the meta-analysis proved that type 1 diabetics have a high dental caries risk. Clinical significance: It is necessary to be aware of all risk factors for dental caries that may be associated with these patients, making it possible to include them into an individualized prevention program. KEYWORDS dental caries, diabetes mellitus, oral health 1 | INTRODUCTION Diabetes mellitus is presented as a set of metabolic disorders that are characterized by hyperglycemia resulting from a deficiency in insulin production and/or action. Chronic hyperglycemia results in a distur- bance in the metabolism of carbohydrates, lipids, and proteins and in numerous long-term complications that cause damage, dysfunction, and failure of several organs. 1-3 Secondary complications resulting from a fluctuation in the blood glucose levels are frequent and occur due to vascular degeneration in different organs. 2 Despite advances in terms of diagnosis, prevention and treatment, diabetic complications remain a major cause of mor- bidity and mortality. 4-6 Type 1 diabetes mellitus includes the cases in which there is a destruction of β-pancreatic cells by autoimmune processes (type 1A) and those in which the etiology and pathogenesis of the destruction is Received: 29 August 2019 Revised: 4 November 2019 Accepted: 17 December 2019 DOI: 10.1111/jerd.12562 J Esthet Restor Dent. 2020;1–19. wileyonlinelibrary.com/journal/jerd © 2020 Wiley Periodicals, Inc. 1