A two-component whitening system has a de-sensitizing effect as well as re-mineralizing capability. The system may be an unfoamed, a foamed or a foamable composition. The system has a first component with at least one peroxide compound, at least one source of phosphate and at least one gelling agent; and a second component with at least one source of calcium, strontium and/or mixtures thereof. The second component may also contain at least one gelling agent, and the composition maybe present as a foam or is foamable. The composition may be packed in a two-compartment syringe.