Prevalence of Mechanical and Biological Complications of Dental Implants in Diabetic Versus Non-diabetic Patients: An Institutional Database Study

Introduction: Diabetes mellitus may adversely influence peri-implant tissue health and outcomes. The aim of this study was to evaluate and compare the prevalence of mechanical and biological complications associated with dental implants in diabetic and non-diabetic patients and to assess the influence of glycemic control. Materials and Methods: This retrospective observational study was conducted using the institutional database records from January 2019 to December 2023. A total of 168 patient's database were included and equally divided into diabetic (n = 84) and non-diabetic (n = 84) groups based on their medical history and glycated hemoglobin (HbA1c) levels. Inclusion criteria comprised adult patients (≥18 years) with single endosseous implants and a minimum loading period of 12 months. The assessed mechanical complications included abutment screw loosening, prosthetic screw fracture, veneer fracture, framework fracture, and occlusal wear. Biological complications included bleeding on probing, suppuration, probing depth ≥6 mm, radiographic bone loss ≥2 mm, and peri-implantitis. Patients with diabetes were further stratified into controlled (HbA1c ≤7%) and uncontrolled (HbA1c >7%) groups. Statistical analysis was performed, with p < 0.05 considered statistically significant. Results: The mean age was significantly higher in diabetic patients (58.4 ± 9.7 years) compared to non-diabetic patients (54.1 ± 10.3 years; p = 0.003). Biological complications were significantly more prevalent in diabetic patients, including bleeding on probing (odds ratio (OR): 2.94; p < 0.001), suppuration (OR: 3.33; p = 0.007), probing depth greater than or equal to 6 millimeters (OR: 3.17; p = 0.002), radiographic bone loss ≥2 millimeters (OR: 3.27; p = 0.003), and peri-implantitis (OR: 3.73; p = 0.002). Biological complications were observed in 54 (64.3%) diabetic patients compared with 31 (36.9%) non-diabetic patients (p < 0.001). Mechanical complications were more frequent in patients with diabetes, with abutment screw loosening being significantly higher (p = 0.026), while other mechanical complications were not statistically significant. Among diabetic patients, those with uncontrolled glycemic status showed significantly higher biological complications than control patients, including peri-implantitis (p = 0.028). Conclusion: Diabetes mellitus, particularly poor glycemic control, significantly increases the risk of biological complications in dental implants, whereas mechanical complications are less affected. Careful patient selection, metabolic control, and rigorous maintenance are essential for achieving optimal implant outcomes.