Fig. 4

mRNA expression of SOST in MLO-Y4 cells treated with Ti particles (0 (control), 0.1 mg/mL and 1.0 mg/mL) for 24 h and 48 h. Real-time PCR was performed, and GAPDH was used as an endogenous control. Results are expressed as the fold change relative to the control group. a At 24 h, treatment with 1.0 mg/mL of Ti particles significantly increased SOST mRNA expression compared with the control group (*p < 0.05). b At 48 h, treatment with 0.1 mg/mL or 1.0 mg/mL of Ti particles significantly increased SOST mRNA expression compared with the control group (*p < 0.05). The group treated with 1.0 mg/mL of Ti particles also differed significantly from the group treated with 0.1 mg/mL (*p < 0.05)