The present invention relates to compositions and methods of whitening teeth of a subject in need thereof, by applying a safe and effective amount of a composition to a plurality of teeth, the composition comprising: a. a safe and effective amount of a bleaching agent； b. a safe and effective amount of a water insoluble solid phase； c. a safe and effective amount of a water soluble liquid phase； wherein the ratio of the water insoluble solid phase to the water soluble liquid phase is from about 1:4 to about 4:1； wherein the composition is applied for a sufficient period of time to achieve whitening； and wherein in one embodiment the composition has a Whitening Index of from about 0.5 to about 4. The composition optionally comprises a hydrophobically modified polymer. The present invention also relates to a delivery system comprising the present compositions used with an integral carrier, e.g. a strip material, dental tray or sponge material.
