This trial aims to study the effect of photoactivated disinfection using Diod laser (810 nm) to activate photosensitive nanoparticle chitosan as an endodontic irrigant versus sodium hypochlorite followed by saline and then EDTA 17% on 1) postoperative pain and 2) the success of revascularization in patients with necrotic immature maxillary anterior teeth using a randomized clinical trial design.

randomized clinical trial will be conducted to investigate and compare the efficacy of photosensitized nano-chitosan 2% as an endodontic disinfectant during revascularization versus sodium hypochlorite, followed by EDTA 17% according to the standardized protocol of the American Association of endodontics.

Twenty individuals with necrotic, immature permanent anterior teeth will be recruited. They will be randomly assigned into two groups according to the received intervention: control group and test group.

pain will be evaluated as a primary outcome at 24 hours and one week post-intervention using numerical rating scale (NRS). In addition, the root development in terms of change in root length and apical foramen diameter and periapical bone healing will be evaluated as secondary outcomes using cone beam tomography.

Inclusion Criteria:

• o Immature necrotic maxillary incisor with open apex greater than 1 mm.

  • Teeth where pulp space are not needed for post and core.
  • A restorable tooth.
  • Patients should be free from any systemic disease that may affect normal healing and predictable outcome.
  • Patients who will agree to the consent and will commit to follow-up period.

Exclusion Criteria:

• o Non-restorable teeth.

  • Teeth with root fractures, internal or external root resorption.
  • Teeth with mature fully developed root with closed apex
  • Patients with any systemic disease that may affect predictable outcome