Introduction. One of the priority issues of contemporary dental therapy is chronic apical periodontitis. This disease presents an inflammatory reaction of the periapical tissues and mass destruction with the bone tissue resorption in the root apex region. Despite the fact that endodontic treatment is performed with a perfect sterilization of the root canal system, there are cases when surgical treatment is indicated - with the resection of the affected root apex.  Aim of the study. To determine the effectiveness of calcium hydroxide preparations in the regeneration of periapical tissues as well as the role of surgical treatment of teeth that do not respond to endodontic treatment.  Materials and methods. The study included 12 patients who were clinically and paraclinically examined. The root canal therapy was performed using calcium hydroxide preparation Metopex. Following the root canal treatment, 2 of the 12 cases with clinical forms were not managed therapeutically, being subjected to surgical treatment.  Results. The use of endodontic curative material contributed to the pathogenic flora destruction in the root canal system. In cases where the pathological process was not stopped using the curative material, surgical treatment was performed.  Conclusion. The clinical trial highlighted the favorable treatment with calcium hydroxide curative materials, but there are cases when the treatment can not be stopped and the surgical treatment is used.