This clinical study aims to investigate the predictability of revascularization procedure of immature necrotic human permanent teeth with apical periodontitis. The quality of root development (thickness and length) will be assessed radiographically.

All teeth will be disinfected using either triple antibiotic paste (a mixture of metronidazole, ciprofloxacin and amoxicillin mixed with sterile glycole) or non setting calcium hydroxide applied to the pulp space with a sterile lentulospiral and then closed temporarily with a sterile sponge and temporary restoration for 2-3 weeks to allow disinfection of the canals teeth will be reentered under rubber dam isolation and all intracanal medicaments will be washed out from the canal using 10 ml of 2.5% sodium hypochlorite and 20 ml of Ethylene diamine tetra acetic acid (EDTA). Then, a sterile endodontic file will be inserted past the canal terminus into the periapical tissues to induce bleeding to fill the canal space as much as possible and subsequently sealed with a double coronal seal using bioceramic repair material and composite filling. All the teeth will be monitored clinically and radiographically on a biannual basis.

Inclusion Criteria:

1. Teeth diagnosed with necrotic pulp with/without evidence of apical periodontitis.
2. An immature/open apex.
3. Tooth does not need post and core restoration.
4. Medically healthy patients with no known allergy to used materials.

Exclusion Criteria:

1. Medically compromised patient,
2. Teeth with periodontal involvement
3. Teeth with vertical root fractures,
4. Non-restorable teeth,