Revitalization of Young Immature Permanent Teeth With Necrotic Pulps Using Autologous Stem Cells from Human Exfoliated Deciduous Teeth

Irreversible damage to immature permanent teeth as a result of noxious infection or local trauma before normal physiological closure of the apical structure represents a real clinical challenge. The conventional therapeutic approach is to consider the use of synthetic biocompatible materials, such as calcium hydroxide [Ca(OH)2] and mineral trioxide aggregate (MTA), to induce apical closure, or apexification, by forming a hard tissue barrier across the root apex. However, neither MTA nor calcium hydroxide are currently able either to induce or stimulate pulp regeneration, or to ensure that conventional root development continues once damage has taken place, so that the inherent risk of root fracture remains.

Millions of teeth are accidentally avulsed each year due to the serious trauma in sports, motor vehicle accidents, criminal assaults, and fist fights, among other incidents. The risk is higher in children while their permanent teeth are still immature which may led to lots of complications and also more challenges in treatment. Generally, tooth reimplantation is the most effective therapy for tooth avulsion, As we know, The success of tooth reimplantation depends on the maintenance of vitality of the periodontal ligament, which need the parents and teachers act quickly (e.g., within 2 h) and that the avulsed tooth should preserved in an appropriate medium, such as milk or physiological saline, because the viable cells in the remaining periodontal ligament (PDL) on the root surface play a crucial role in recovering the avulsed tooth functions.

Along with the development of new regenerative protocols to resolve clinical deficiencies, continuing advances in the discovery and characterization of stem cells of dental origin-able to differentiate into multiple tissue types-have recently broadened possible therapeutic horizons towards pulp and periodontal tissue regeneration. Some studies have suggested that the recent discovery and characterization of stem cells from human exfoliated deciduous teeth (SHED) form the cell source of apexogenesis in immature teeth with periradicular periodontitis of endodontic origin. The purpose of this clinical trial is to both clarify the efficiency of autologous SHED to regenerate pulp and periodontal tissue in the patients with immature permanent teeth and pulp necrosis to confirm the safety of using autologous stem cells in clinical endodontic regenerative medicine.

This is a single-centre, randomized, controlled study. This study has been approved by the ethical committees of School of Stomatology, Fourth Military Medical University. The study will be conducted according to the Declaration of Helsinki.

Inclusion Criteria:

1. Those who has signed the informed consent.
2. Those who are between 7-years-old to 12-years-old.
3. Those with at least one young permanent teeth with pulp necrosis which caused by trauma or permanent incisor avulsed by trauma.
4. Those who can provide the health deciduous teeth.
5. Those who have accomplished initial preparation and have been showing good compliance.
6. Those whose guardians understand the purposes of the trial and are capable of making an independent decision to comply with trial requirements
7. Those who are able to visit our hospital in accordance with the trial schedule

Exclusion Criteria:

1. Those in an extremely poor nutritional condition (serum albumin concentration <2 g/dL)
2. Those whose guardians would not cooperate with the treatment.
3. Those who has uncontrollable oral disease.
4. Those with severe dental fear.
5. Those with coexisting mental or consciousness disorder.
6. Those with teeth dysplasia and/or hereditary disease history.
7. Those with systemic disease which may affect the postoperative healing.
8. Those with bruxism and malocclusion.
9. Loss of the avulsed teeth.
10. Those who are taking the medicine which would affect the postoperative healing.
11. Those with the bad oral habits.
12. Those who are undertaking other trail meanwhile or few weeks ago.
13. Those coexisting disease of the blood or immune system.
14. Those who are not capable to provide the deciduous dental pulp cells.
15. Those with the severe tooth trauma (crown-root or root fracture, tooth displacement).
16. Others who the investigators or sub-investigators determined as unsuitable for the trial.