The study was not started due to the lack of funding.

In this clinical trial the investigators will evaluate an alternate treatment option, which was developed for teeth with incomplete roots, called Regenerative Endodontic Procedure (REP). This treatment works by harnessing the blood clot formed within the root canal from tissues surrounding the root as a scaffold for stem cells. These cells could help to increase the thickness and length of the root canal walls resulting in root end maturation.

Results from the 50 participants who will receive the REP treatment will be compared with findings with historical data.

All participants will be prospectively assigned to the REP treatment group. Results from the treatment group will be compared to historical controls of all subjects treated by Ca(OH)2 or MTA apexification in the last 10 years (2007-2017) at the Boston University Henry M Goldman School of Dental Medicine.

All materials used in this protocol are FDA approved and commercially available for similar applications. This study does not seek a new use or application of any materials, instead recommendations of the American Association of Endodontists (AAE) will be followed to evaluate outcomes associated with the REP compare to the standard of care Ca(OH)2 or MTA apexification.

The overall objective for this research is the elimination of any clinical symptoms and the evidence of bony healing as examined by radiographs.

Other objectives include increased root wall thickness and/or increased root length and positive response to vitality testing, which if achieved, could indicate a more organized vital pulp tissue.

Inclusion Criteria:

Subjects followed prospectively

• 7-18 years old
• salvageable permanent non-vital tooth with immature apex whether anterior or posterior
• receiving dental care at the Henry M. Goldman School of Dentistry Historical controls
• 7-18 year old
• salvageable permanent non-vital tooth with immature apex whether anterior or posterior
• received care and has accessible records at the Henry M. Goldman School of Dentistry
• had either the Calcium hydroxide apexification or MTA apexification between 2007 and 2017

Exclusion Criteria:

• allergic to medications necessary to complete procedure
• health status not in: a) ASA-1 no organic pathology or patients in whom the pathological process is localized and does not cause any systemic disturbance or abnormality; nor b) ASA 2 A moderate but definite systemic disturbance, caused either by the condition that is to be treated or surgical intervention or which is caused by other existing pathological processes
• history of dental trauma within 6 months due to possibility of internal and external root resorption.
• if tooth pulp space is needed for post/core final restoration
• pregnancy in female subjects