Figure 12: Quantitative analysis of VEGF and BMP-2 proteins was performed with conditioned medium between OSS treatment and control group. VEGF protein of OSS group was significantly different (30 and 120 min/day; , 10, 60, and 180 min/day; ). BMP-2 protein of OSS induction group also showed significant differences (60, 120, and 180 min/day; ). Overhead brackets with asterisks indicated significant differences between groups.