Due to the noteworthy prevalence of inflammatory periodontal diseases among the population, especially in older age groups, the problem of providing timely and quality care to prevent severe complications leading to tooth loss becomes urgent. Conventional approaches to treatment are not always successful and do not necessarily provide a lasting effect. Therefore, predicting the outcome of the disease is a critical task. Material and Methods — We performed examination of 169 individuals and treatment of 126 patients aged 45-75 years with mild to moderate localized periodontitis of traumatic etiology (LPT) were performed. We employed clinical, radiological, and functional methods of examining periodontal condition, and investigated laboratory blood parameters (complete blood count, C-reactive protein). To assess the body’s adaptive resources, the entropy of the leukocyte blood count was calculated, and risk factors for the occurrence of LPT were assessed. Predicting the course of LPT based on changes in clinical and radiological indicators was accomplished by assessing treatment outcomes and calculating a prognostic score. Results — Patients exhibited a noteworthy prevalence of somatic pathology, with cardiovascular diseases (RR=2.32), anemia (RR=2.26), and gastrointestinal tract disorders (RR=1.88) emerging as predominant conditions (p<0.001). The duration of the disease exceeding three years was associated with a 2.06-fold increase in the risk of developing moderate-grade LPT (p=0.017). With a concentration of C-reactive protein in the range of 3-10 mg/L, the risk of developing moderate-grade LPT increased 1.74-fold (RR=1.74; p=0.0022). The intense type of adaptive reaction of the body was detected in 30.4% and 50.7% of cases with mild and moderate grades of LPT, respectively, increasing the risk of a more severe grade by 1.8 times (p=0.0026). Pronounced local changes in the bone tissue of the alveolar process were observed 1.6-2 times more often in cases of moderate periodontitis vs. mild LPT (p=0.0035). Microcirculation in the inflammation zone decreased by 32% and 50.1% with mild and moderate grade of the disease, respectively (p<0.001). Splinting of teeth in the area of the pathological focus during treatment led to improved clinical indicators vs. the control group (p=0.012). Conclusion — Based on the study results, the prognosis for the course of LPT was most significantly influenced by the following factors: the concentration of C-reactive protein, the grade of LPT, the entropy of the leukocyte blood count, changes in the alveolar bone of the jaw, the duration of the disease, the history of previous periodontal treatment, and tooth splinting. Calculation of a prognostic score for the treatment outcome of LPT allows to qualitatively assess the clinical situation and identify a group at risk of an adverse treatment outcome.