Disclosed is a process and composition for bleaching teeth made up of two components blended together before each application. The method and composition offers faster results while significantly reducing the possibility of user discomfort. One of said components comprises carbamide peroxide, the other contains salts and hydroxides and/or oxides of metals belonging to the first or second group of the Periodic Table which stimulate the generation of radical oxygen. In one embodiment, the first part comprises up to 50% water by weight and optionally comprises a stabilizer. In some embodiments, the first component is substantially colorless and the second component comprises a dye indicator which discolors or loses color when exposed to radical oxygen generated by the mixing of the two components.