Effect of Cryopreservation on the Structural and Functional Integrity of Human Periodontal Ligament Stem Cells: A Systematic Review

Abstract

Aim: The aim of the present systematic review was to assess the effect of cryopreservation on the human periodontal ligament (PDL) stem cells and their ability for periodontal regeneration. Materials and Methods: An electronic search without time restrictions was conducted up to August 2017 in indexed databases using the combination of different keywords including cryopreservation, cryofixation, vitrification and human periodontal ligament stem cells. The exclusion criteria included reviews, commentaries, letters to the editor, interviews and updates. The relevant articles were included and data extraction was processed. Results: Dimethyl sulphoxide was used as a cryoprotectant in all the studies which yielded good results. The magnetic freezing proves to be better than the normal freezer. The cryopreserved cells showed no significant difference for viability, proliferation, and regenerative capacities as compared to the fresh human PDL stem cells (PDLSCs), in vitro as well as in vivo. Conclusion: Cryopreservation of the human PDLSCs would serve as an opportunity for future regenerative therapy for the periodontium.