The Effect of Different Intracanal Medicaments on Periapical Lesion Healing

Inclusion Criteria: The study is planned to include patients aged 18-60 years who are systemically healthy (ASA I-II), present with apical periodontitis after primary root canal treatment, and have single-rooted, root-filled mandibular teeth with a periapical index (PAI) score of ≥3. Endodontic treatment failure is to be evaluated based on clinical and radiographic examinations. The duration of the initial endodontic treatment is to be at least four years or longer and/or the teeth are to exhibit clinical symptoms and signs. Previous root canal fillings are to be assessed for obturation quality and classified as satisfactory if they meet the following criteria: no visible voids, good condensation, and termination within 1-2 mm of the radiographic apex. If one or more of these criteria are not fulfilled, the obturation is to be classified as poor quality. The presence of post-treatment apical periodontitis, poor obturation quality, and/or persistent or newly developed symptoms (such as spontaneous pain, tenderness to palpation or percussion) and/or sinus tract formation are to be considered as indications for retreatment. Exclusion Criteria: Patients with a history of psychiatric disorders, allergic reactions, or pregnancy, and those who have taken analgesics within seven days prior to treatment or antibiotics within the previous three months, are to be excluded from the study. Teeth presenting with a periodontal pocket depth greater than 4 mm, severe coronal destruction preventing rubber dam placement, vertical root fracture, internal or external resorption, ankylosis, overfilling, open apex, or that have undergone surgical or nonsurgical retreatment after primary therapy are to be excluded. Teeth with perforation or fractured instruments are also to be excluded.