“…Replantation of an avulsed tooth within 5 min of avulsion usually ensures prompt return of the PDL cells to their normalcy. 20,22 In case of more than 15 min of dry storage time, the precursor, progenitor, or stem cells are no longer able to differentiate into fibroblasts, 1,2 and after 30 min of dry storage, virtually all of the PDL cells that are remaining on the root surface are likely to have become necrotic hence the poor long-term prognosis. [1][2][3]23 Studies have been done focusing on either cell-based therapy or activation of endogenous repairing systems induced by additional biological cues.…”