Background: Type 1 diabetes mellitus is a chronic metabolic disease of autoimmune origin with early manifestations, which occur predominantly in childhood. Its incidence has been increasing in most European countries. Diabetes is a well-known predisposing factor for oral diseases; therefore, prevention at an early age is essential. Diabetes negatively affectsdeveloping enamel by altering the mineralization process, which can have a detrimental effect on oral health. Diabetes mellitus (DM) may affect the healing and survival of root-filled teeth with periapical lesions. Methods: An electronic search of the following databases was carried out to identify the literature evaluating the effect of type 1 diabetes on children's primary teeth: PubMed, Cochrane Library, Google Scholar, and Embase. In total, 1244 studies were identified. After removing duplicates (n = 52), then screening based on title and abstract, and then performing full-text screening, a total of nine articles were included in this systematic review. Conclusion: This systematic review revealed that type 1 diabetes does not significantly increase the risk of dental caries or periodontal lesions for children's primary teeth.