a dentin adhesive system using succinic acid modified hydroxyethylmethacrylate (SA-HEMA); the primers consist of NTG-GMA, cyclopental dimethacrylate (CPDM), and tricyclic dimethacrylate (TCDM); the adhesive consists of bisphenol GMA, urethane dimethacrylate (UDMA), and HEMA