Abstract: The present invention provides a tooth whitening film. The tooth whitening film comprises a dental bleaching agent comprising one or both of a non-hydrogen peroxide bleaching agent and hydrogen peroxide in a hydrogen peroxide-polymer complex, one or more polyphosphates, said one or more polyphosphates comprising one or more cyclic polyphosphates, one or more water soluble film-forming polymers, one or more plasticizers and one or more emulsifiers, wherein the film has a thickness from about 50 ?m to about 500 ?m. A kit comprising one or more such films having a thickness from about 50 ?m to about 150 ?m and a dental aligner is also provided. A process for the manufacture of the film is also provided, together with a method of using such a film to bleach teeth.