Introduction. The diagnosis and treatment of chronic apical periodontitis are among the most important components of dental pathology. The periodontium is a complex anatomical structure of conjunctive origin, distributed between the internal hard lamina and the radicular cementum and is in direct connection with the alveolar bone and the pulp through the apical foramen, and with the periosteum and gums through the dental margin. Aim of study. To determine the effectiveness of the mechanical treatment and therapy combined with lubricants and irrigation solutions with antibacterial action. Methods and materials. 12 patients aged 35-50 years, seeking prosthetic care, were subjected to endodontic treatment. The patients were examined clinically and paraclinically. The teeth showed signs of chronic fibrous apical periodontitis. Endodontic treatment in chronic fibrous periodontitis involved the use of antiseptic medication associated with the mechanical treatment and the therapy combined with antibacterial irrigation solutions and lubricants in order to neutralize degraded organic substances. Results. The results obtained after an effective root canal treatment were analyzed at the first visit by using clinical and paraclinical tests (radiography), as well as in the follow-up post-therapy rehabilitation of patients at intervals of 3 months, 6 months, 12 months, by monitoring the clinical and radiovisiography parameters. Conclusion. Endodontically treated teeth, according to radiographic data, showed uniformly filled canals without any gaps.