Purpose

The American Academy of Pediatric Dentistry (AAPD) recognizes the emerging field of regenerative medicine and encourages dentists to follow evidence-based literature in order to educate parents about the collection, storage, viability, and use of dental stem cells with respect to autologous regenerative therapies. The AAPD also recognizes that harvested dental stem cells is an emerging science which may have application for oral health care but at present there are no treatments available using harvested dental stem cells in humans. This policy is related to the use of harvested dental stem cells from a tooth or follicle. This policy does not include stem cells which are intrinsically present for treatment related to regenerative endodontics from the apical papilla or dental pulp cells. Stem cells used for regenerative endodontics and scaffolding have evidenced-based literature to show successful regeneration.1-3

Methods

This policy was developed by the Council on Clinical Affairs and adopted in 2010. This document is an update of the previous version, revised in 2013. This revision included a review of current dental and medical literature and sources of recognized professional expertise related to dental stem cells. A literature search of the PubMed®/MEDLINE database was conducted using the terms: dental stem cell, harvested tooth cell; fields: all; limits: within the last 10 years, humans, English, birth through age 99. Thirty-one articles matched these criteria. Papers for review were chosen from this list and from the references within selected articles. Expert and/or consensus opinion by experienced researchers and clinicians was also considered.

Background

Stem cells are pluripotential cells that can divide and multiply for an extended period of time, differentiating into a diverse range of specialized cell types and tissues. Adult mesenchymal stem cells, of which dental stem cells are a subset, are highly proliferative and have the ability to differentiate into many cell lines.4  The most familiar application of adult stem cell therapy is bone marrow transplantation to treat hematopoietic cancers, metabolic disorders, and congenital immunodeficiency syndromes. Stem cell therapy is undergoing clinical testing for other conditions such as Parkinson’s disease, diabetes, and brain trauma/spinal cord injuries.5,6  Suggested applications related to oral health care have included wound healing and regeneration of dental and periodontal tissues as well as craniofacial structures (e.g., repair of cleft lip/palate).7

Parents may elect to preserve umbilical cord blood of their child for future harvesting of stem cells if autologous regenerative therapies are indicated. Pulpal tissue of exfoliating primary teeth, oral mucosa fibroblasts,8 surgically removed third molars, periodontal ligament,9 and gingival fibroblasts9 may serve as a source of mesenchymal stem cells.2,10

The public is increasingly aware of this emerging science, and more parents are expressing interest in harvesting/banking dental stem cells. While sources of dental stem cells are readily accessible, those cells must be secured and stored properly to maintain the potential to proliferate and differentiate.11,12  Additionally, harvested dental stem cells currently are not very stable and have been known to form tumors in vivo.2  More studies are recommended to assess the safety and efficacy of harvested dental stem cells prior to initiating human clinical trials.2

Policy statement

While there currently are no treatments available using harvested dental stem cells in humans, the AAPD recognizes that this is an emerging science which may have application for oral healthcare.

As the technology continues to evolve, the process of procurement of dental stems cells should be accomplished only with deliberate integrity and appropriate informed consent to assure the highest ethical standards and quality of outcomes.

References

  1. Conde MC, Chisini LA, Demarco FF, et al. Stem cellbased pulp tissue engineering: Variables enrolled in translation from the bench to the bedside, a systematic review of literature. Int Endod J 2016;49(6):543-50. 
  2. Hynes K, Menichanin D, Bright R, et al. Induced pluripotent stem cells: A new frontier for stem cells in dentistry. J Dent Res 2015;94(11):1508-15.
  3. Yang J, Yuan G, Chen Z. Pulp regeneration: Current approaches and future challenges. Front Physiol 2016;7:58.
  4. Govindasamy V, Ronald VS, Abdullah AN, et al. Differentiation of dental pulp stem cells into islet-like aggregates. J Dent Res 2011;90(5):626-52.
  5. Kadar K, Kiraly M, Porcsalmy B, et al. Differentiation potential of stem cells from human dental origin – Promise for tissue engineering. J Physiol Pharmacol 2009;60(suppl 7):167-75.
  6. Nourbakhsh N, Soleimani M, Taghipour Z, et al. Induced in vitro differentiation of neural-like cells from human exfoliated deciduous teeth-derived stem cells. Int J Dev Biol 2011;55(2):189-95.
  7. Nishino Y, Yamada Y, Ebisawa K, et al. Stem cells from human exfoliated deciduous teeth (SHED) enhance wound healing and the possibility of novel cell therapy. Cytotherapy 2011;13(5):598-605.
  8. Miyoshi K, Tsuji D, Kudoh K, et al. Generation of human induced pluripotent stem cells from oral mucosa. J Biosci Bioeng 2010;110(3):345-50. 
  9. Wada N, Wang B, Lin NH, Laslett AL, et al. Induced pluripotent stem cell lines derived from human gingival fibroblasts and periodontal ligament fibroblasts. J Periodontal Res 2011;46(4):438-47.
  10. Eslaminejad MB, Vahabi S, Shariati M, Nazarian H. In vitro growth and characterization of stem cells from human dental pulp of deciduous versus permanent teeth. J Dent (Tehran) 2010;7(4):185-95.
  11. Perry BC, Zhou D, Wu X, et al. Collection, cryopreservation, and characterization of human dental pulp-derived mesenchymal stem cells for banking and clinical use. Tissue Eng Part C Methods 2008;14(2):149-56.
  12. Yildirim S, Zibandeh N, Genc D, Ozcan EM, Goker K, Akkoc T. The comparison of the immunologic properties of stem cells isolated from human exfoliated deciduous teeth, dental pulp, and dental follicles. Stem Cells Int 2016;2016:4682875. Available at: “https://www.hind awi.com/journals/sci/2016/4682875/”. Accessed June 9, 2017. (Archived by WebCite® at: “http://www.webcitation.org/6tkJoR5zd”)