Comparison of Sonic and Ultrasonic Activation on Healing of Apical Periodontitis

The goal of this clinical trial is to learn whether two different irrigation activation methods - passive ultrasonic irrigation (PUI) and sonic activation - help periapical healing in root canal treatments of single-rooted teeth with apical periodontitis. Researchers will also compare these methods with the traditional needle irrigation technique. The main questions this study aims to answer are Do sonic irrigation activation or PUI activation methods lead to faster or better early periapical healing compared with traditional needle irrigation? Is there any difference in healing volume measured by cone-beam computed tomography (CBCT) after 6 months? Participants in this study will: Adults with single-rooted teeth showing apical periodontitis (PAI ≥ 3), Receive root canal treatment using either PUI, sonic activation, or traditional needle irrigation (assigned randomly). Participants will have CBCT scans before treatment and again at 6 months to measure changes in lesion volume. Researchers will analyze the 3D images using specialized software to calculate periapical lesion volumes before and after treatment. The study will evaluate how much the lesion size decreases in each group and whether any activation method improves healing compared with standard irrigation.