Embodiments of the invention are directed to dental compositions comprising: (1) at least one cationically reactive compound; (2) at least one cationic photoinitiator; (3) at least one compound which is: an organic monomer, oligomer or polymer, said compound comprising at least one reactive oxirane, oxetane, or alkenyl ether, (4) at least one compound which is: an organic monomer, oligomer or polymer, said compound comprising at least one reactive acrylate that is capable of forming an interpenetrating network; (5) at least one free radical initiator; and (6) at least one compound which is: an organic monomer, oligomer or polymer, said compound comprising at least one reactive acrylate or methacrylate and at least one oxirane, oxetane, or alkenyl ether.