“…Beside this, the combination of CQ and tertiary amine may present additional disadvantages. CQ, as being relatively hydrophobic, has difficulties in initializing the polymerization in the presence of solvents such as ethanol or water, and therefore showed a reduced degree of conversion, rate of polymerization and tensile strength of adhesive resins [3,7,14]; in addition, tertiary amine is chemically unstable in acidic material, because a reaction acid-base may occur between the acidic components and basic amines leads to the formation of undesirable quaternary ammonium salts, which reduces the longevity of adhesion to dentin over time [2,8,15].…”