TO DETERMINE THE EFFECT OF ALLOGRAFT AND iPRF WITH OR WITHOUT COLLAGEN MEMBRANE ON HEALING OF APICOMARGINAL DEFECTS

Inclusion Criteria: 1. Patients with no general medical contraindications for oral surgical procedures (ASA-I and ASA-II according to the classification of the American Society of Anesthesiologist's). 2. Patients aged 18 years and above, presenting with chronic suppurative apical periodontitis in at least one tooth, 3. Radiographic evidence of apical radiolucency with periodontal pocket depth exceeding 6 mm confined to buccal aspect of the root. 4. Repeated abscess discharge despite satisfactory root canal treatment. 5.Patients with apicomarginal defects showing a denuded buccal bone plate 6.Failed primary root canal treatment 7.Adequate final restoration with no clinical evidence of coronal leakage. Exclusion Criteria: 1. Clinical or radiographic evidence of root fracture. 2. Resorptive processes involving more than apical third of the root. 3. Chronic generalized periodontitis. 4. Failed previous endodontic surgery or failed root canal re-treatment. 5. Any systemic disease contraindicating oral surgery including uncontrolled diabetes and pregnancy, any condition effecting rate of healing like smoking.