Preconditioning mouth rinse, which pre-treats the teeth to better receive a whitening formula containing a photosensitive compound, and a hand-held consumer light source for tooth whitening, which provides rapid tooth whitening, are disclosed. The light source may use a specific range of visible light and also emit heat sufficient to raise the temperature of the teeth a desired amount at a depth up to about 2 mm in the range of about from 1-5.degree. Celsius over a predetermined period of time. The specified wavelengths of the hand-held consumer operable light will activate the photosensitive substance in the whitening formula. The oxidizing compounds may be transparent to light enabling light energy to activate the oxidizing compounds directly on the tooth surface, or to activate a photosensitizing or photosensitive compound added to produce the desired temperature increase.