This study aimed to comprehensively assess the impact of type 1 diabetes mellitus (T1DM) on the periodontal status of adolescents. A cross-sectional comparative study involved 180 adolescents aged 12–18 years, divided into groups: patients with compensated T1DM (n=80), conditionally healthy individuals (n=80), and adolescents with periodontitis associated with poor oral hygiene (n=20). The methodology included clinical assessment of periodontal indices (BOP, PPD, CAL), quantitative determination of key periodontopathogenic bacteria (Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola) using real-time PCR, and analysis of biochemical markers (interleukin-1β, matrix metalloproteinase-8, osteoprotegerin) in oral fluid. The results revealed that adolescents with T1DM, compared to their healthy peers, had a 2.5 times higher bleeding index (BOP: 25.0% vs. 10.5%, p<0.001), an elevated concentration of IL-1β in saliva (65.8 pg/mL vs. 25.5 pg/mL, p<0.001), and an 11.6-fold increase in P. gingivalis levels (5.8×10³ vs. 0.5×10³ copies/mL, p<0.001). At the same time, no significant loss of clinical attachment was observed, indicating a predominance of severe gingivitis over destructive periodontitis. A direct correlation was established between the level of glycated hemoglobin (HbA1c) and inflammatory parameters: with BOP (ρ=0.47) and with IL-1β (ρ=0.52). The obtained data indicate that T1DM in adolescents is a significant risk factor for the development of pronounced periodontal inflammation. Its pathogenesis is primarily associated with a systemic pro-inflammatory status induced by hyperglycemia, rather than with an aggressive microbial factor. The results justify the necessity of mandatory inclusion of periodontal screening and preventive dental interventions into the standards of interdisciplinary management for adolescents with T1DM.
