THE PURPOSE OF THE PRESENT INVENTION IS TO PROVIDE AN ORAL COMPOSITION THAT ENABLES A HIGH LEVEL OF WHITENING EFFECTIVENESS TO BE OBTAINED OVER THE ENTIRE APPLICATION AREA OF THE ORAL COMPOSITION. THE PRESENT INVENTION DISCOVERED THAT A TOOTH WHITENING COMPOSITION WITH A HIGH LEVEL OF WHITENING EFFECTIVENESS OVER THE ENTIRE TOOTH WHITENING COMPOSITION APPLICATION AREA CAN BE OBTAINED BY INCLUDING COLLOIDAL PLATINUM AS A PLATINUM CATALYST IN A PEROXIDE-CONTAINING ORAL COMPOSITION. THE PRESENT INVENTORS ALSO DISCOVERED THAT WHITENING EFFECTIVENESS CAN BE ENHANCED BY APPLICATION OF A TOOTH WHITENING COMPOSITION COMPRISING COLLOIDAL PLATINUM TO THE TEETH SURFACE FOLLOWED BY PHOTO-IRRADIATION OF THE APPLICATION SITE. (FIG. 2)
