Effects of TEGDMA (A) and HEMA (B) on HDPC ALP activity. Cells were exposed to 0.5 mM TEGDMA and 2 mM HEMA for 24 hrs. Before assaying ALP activity, cells were incubated in growth medium (NM) or differentiation medium (DM) for 6 days. ALP activity (units/mg protein) is expressed as% of the control. Each error bar represents the standard deviation of three independent experiments. * indicates significant (p < 0.05) differences between the control and test groups.