Evaluation of Bone Healing After Obturation With Dia-Root Bio Sealer (Calcium Silicate-based Sealer CSBS) Using Three Obturation Techniques

Inclusion Criteria: * Medical condition: Medically free patients. * Age: Ranging from 20-50 years old * Gender: Male and female patients * Teeth: Patients with mandibular permanent mature molar(s) diagnosed with necrotic pulps and with apical periodontitis (asymptomatic, symptomatic apical periodontitis, or chronic periapical abscess), with at least one of the roots showing radiographic evidence of periapical lesion. * Preoperative radiographic (CBCT) lesion size should range from 2 - 4 mm. * Patients who fulfill these criteria, agree to participate, and sign the informed consent Exclusion Criteria: * Participants with generalized periodontal disease, and those who are pregnant, breastfeeding, or have any systemic disease. * Teeth diagnosed with immature apices, root resorption, or non-restorable. * Patients in which the clinical assessment necessitates multiple-visits treatment, such as those with signs and symptoms of acute or diffuse infection. * Patients who had pre-treatment antibiotic therapy or analgesics and within 7 days. * Patients who fail to complete their final restoration postoperatively. * Patients who will refuse to sign the informed consent. * Root canals requiring apical preparation larger the #40.