Objective: The purpose of the present study was to assess the influence of type 2 diabetes mellitus (DM) on the evolution of pulpal and periapical pathology. Method and materials: Two reviewers independently conducted a systematic search for articles published between 1 January 2001 and 31 December 2018 on MEDLINE/PubMed, ISI Web of Science, and Scopus databases. An additional manual search was also carried out. Results: Ten studies fulfilling the inclusion criteria were included in the review (two longitudinal studies with 1-year follow-up comparing the success of primary root canal treatment between type 2 diabetic patients and non-diabetic patients, and eight cross-sectional studies). Analysis of the ten studies showed that inadequate control of type 2 DM may predispose and influence the inflammatory pulpal and periapical disease evolution. Conclusions: The present systematic review suggests that there are biologic bases to suggest that type 2 DM may act as a risk factor for developing an endodontic pathology, affecting the course of the disease in terms of susceptibility, prevalence, progression, and tissue healing capacity as a consequence of a disrupted immune response. However, more well-designed clinical investigations carrying out suitable research methodologies are needed to elucidate the influence of type 2 DM on the pulpal and periapical disease evolution. Schlagwörter: dental pulp, diabetes, endodontics, periapical pathology, systematic review