This study aims to compare regenerative endodontics for necrotic young permanent anterior teeth using oral photo-activated disinfection versus triple antibiotic paste in terms of:

1. Clinical success in terms of absence of any complication such as spontaneous pain, sinus or swelling.
2. Radiographic success in terms of healing of periapical radiolucency or increase root thickness, length or apical closure.

Disinfection of the root canal system is thought to be critical to the success of Regenerative Endodontic Procedures (REPs) as infection prevents regeneration, repair and stem cell activity . A suitable material for using as intra-canal medicament seems to be antibiotic. Triple antibiotic paste (TAP) containing metronidazole, ciprofloxacin and minocycline has been reported to be a successful regimen in controlling the root canal pathogen and in managing necrotic young permanent tooth .

Recently, new disinfection methods have been developed to overcome the limitations of conventional disinfecting protocols that they may neither reduce the number of bacteria to a satisfactory level nor minimize the toxicity to periapical stem/progenitors . Other concerns regarding the use of TAP are tooth discoloration after treatment and bacterial resistance. Photo-activated oral disinfection is a novel disinfection method which present a great solution for the problem associated with triple antibiotic paste

Inclusion Criteria:

• Healthy children with no physical, mental or systemic conditions.
• Developmental age of the child is the most important factor so periapical x- ray will be taken first to assure apex immaturity.
• No sex predilection.
• Restorable necrotic young permanent anterior teeth

Exclusion Criteria:

• Root fracture.
• Internal or external root resorption.
• Parents or guardians refuse to participate in the study.