Purpose: To evaluate glycated hemoglobin (HbA1c) levels in patients who have not been diagnosed with diabetes mellitus (DM) but exhibit oral DM symptoms prior to dental implant surgery. Materials and Methods: This study was designed as a retrospective cohort. It was conducted on patients who previously presented to the Department of Oral and Maxillofacial Surgery for dental implant surgery and had not been diagnosed with DM. The inclusion criteria were as follows: patients with the need for dental implants and augmentation, presence of oral DM symptoms, and access to blood test results that included HbA1c. Patients with a prior diagnosis of DM were excluded from the study. Results: A retrospective analysis was conducted on data from 253 patients who applied for dental implant surgery. Among them, 72 patients underwent HbA1c level assessments via blood tests. Patients with previously uncontrolled DM (n = 21) and those whose blood tests were performed at different institutions (n = 8) were excluded from the study. Consequently, the study encompassed a cohort of 43 patients. Among the participants, 55% of them were female and 45% of them were male. The HbA1c values of the patients ranged from 5.1 to 10.9, with an average value of 6.57 ± 1.44. Of the patients, 41.8% were diagnosed with DM, 30.2% were prediabetic (preDM), and 27.9% did not receive any diagnosis. There was no statistically significant relationship between the combinations of xerostomia, delayed wound healing, oral infection, burning sensation in the mouth, periodontitis, and dental caries with HbA1c levels (P > .05). In this study, patients presenting to the clinic for dental implant surgery were directed based on oral symptom findings, and the rates of diagnosed DM and preDM were determined to be 7.11% and 5.14%, respectively. Conclusions: Considering the negative effects and prevalence of uncontrolled DM, it may be recommended to assess the HbA1c levels in patients with oral symptoms before dental implant surgery.