Fig. 4

A Expression of RANKL protein in osteogenic differentiated DPSCs by immunofluorescence at 14 or 21 days showed discrete cells with homogeneous faint weak (1+) expression with dim fluorescence intensity found in DPSCs cultured with smoke extracts with a reduction in both the number and intensity [yellow arrows] compared to the untreated control cells which showed increased cells with strong (3+) expression intensity of RANKL protein. The magnification [10X] (scale bar-50 μm). B Bar chart showed a significant difference between the RANKL protein expression of TE-p, e-Cig-LV, and un-exposed DPSCs on DPSCs after 14 days of exposure (p < 0.0001). Data were presented as mean and SD; no significant difference existed between the RANKL protein expression of TE-p, e-Cig-LV (p > 0.05). C Bar chart showed a significant difference between the RANKL protein expression of TE-p, e-Cig-LV, and control DPSCs after 21 days of exposure (p < 0.0001). *: significant difference compared to un-exposed DPSCs, #: significant difference compared to DPSCs exposed to TE-p extract