Fig. 3

Determination of cell proliferative potential by MTT assay. The periodontal ligament stem cells (PDLSCs) from fresh sheets (fPDLSC sheet) have a similar proliferation rate when compared to fresh PDLSCs (fPDLSCs) at 24 h. PDLSCs derived from the cryopreserved sheets (cPDLSC sheet) exhibited a slightly slower proliferation rate compared to those from the freshly prepared sheets and fPDLSCs in the first 24 h following the inoculation in α-MEM. However, the three groups of cells showed roughly the same proliferative potential at 48 and 72 h. P =0.8055, fPDLSC versus fPDLSC sheet; P =0.5281, fPDLSC versus cPDLSC sheet; P =0.6313, fPDLSC sheet versus cPDLSC sheet. All P > 0.05. MTT 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, OD optical density