In addition to macro and microvascular complications that are associated with the disease, hyperglycaemia is also a risk factor for several oral complications. The aim of this study is to establish a relationship between dental caries in patients with type 1 diabetes mellitus treated with multiple insulin injections and that of individuals without diabetes. It is also an aim to characterize the oral hygiene habits of this population. Material and Methods:An observational clinical study of analytical and cross-sectional nature was conducted. Thirty patients with type 1 diabetes mellitus and 30 individuals without diabetes were observed and questioned about information regarding their medical history. Oral examination was conducted according to the standards of the World Health Organization and ICDAS was used for caries detection. Statistical analysis was performed and the significance level was set at 5%. Results: Patients with diabetes mellitus showed similar caries levels to that of individuals without diabetes. Patients with diabetes mellitus had a higher dental plaque index. Only 10% of the patients having episodes of nocturnal hypoglycaemia brush their teeth after glucose intake. Discussion: Although there's some controversy in the literature regarding the prevalence of caries in patients with diabetes mellitus, the results are in agreement with a great number of studies. However, patients with diabetes mellitus have a higher plaque index which can be associated with a higher risk for developing certain oral pathologies. Conclusion:No statistically significant association was found between type 1 diabetes mellitus and dental caries.