PTGS2 and dental caries: These can be due to stimulation of ROS and isoprostane production, activation of ATM/Chk2 signaling, induction of HO-1, COX-2 and p21 expression, and the inhibition of cdc2, cdc25C, cyclin B1 (Fig 9). These results are important for our understanding of the mechanism of pulp necrosis and tissue inflammation after clinical operative restoration of dental caries by dentin bonding agent and composite resin.