Disclosed herein are non-aqueous compositions including: a flowable Part A including at least one resin and Reactant A; and a flowable Part B including at least one resin and Reactant B; wherein at least one of flowable Part A and flowable Part B further includes a free radically polymerizable resin; wherein at least one of flowable Part A and flowable Part B further includes a free radical initiator system; wherein flowable Part A and flowable Part B are capable of being mixed to provide a flowable mixed composition; wherein when flowable Part A and flowable Part B are mixed, Reactant A and Reactant B are capable of interacting to cause a non-free radical reaction within a first staging time to provide a first staged stable consistency for the mixed composition; wherein Reactant A comprises an acid and Reactant B comprises a base, and upon mixing flowable Part A and flowable Part B, the Reactant A acid is capable of reacting with the Reactant B base in an ionic acid-base reaction; and wherein the mixed composition having the first staged stable consistency is capable of forming a hardened dental composition upon initiation of free radical polymerization.