Methods for whitening teeth

1. A method of whitening teeth, comprising:

applying a layer of a translucent tooth-whitening composition containing a peroxide dose to at least one tooth, wherein the peroxide dose includes a total amount from about 2 mg to about 40 mg of peroxide active within the layer of the tooth-whitening composition, and the tooth-whitening composition is translucent and is applied to the at least one tooth by a translucent strip or tray;

maintaining the tooth-whitening composition on the at least one tooth for a first time period without an application of light radiation; and

after the first time period, and while the tooth-whitening composition remains on the at least one tooth, directing a light radiation toward the at least one tooth for a second time period, the first time period having a duration greater than 50% of a total duration of the first and second time periods, wherein the light radiation is directed toward the tooth through the translucent strip or tray and through the translucent tooth-whitening composition, and the radiation intensity is not greater than about 150 mW/cm 2 ; and

removing the tooth-whitening composition from the at least one tooth.

2. The method of claim 1 , wherein the duration of the first time period is at least 80% of the total duration of the first and second time periods.

3. The method of claim 1 , wherein the light radiation is selected for absorption by a stain on the at least one tooth by selecting a wavelength corresponding to a color substantially opposite to a color of the stain on the 1976 CIE LAB color scale.

4. The method of claim 1 , wherein the light radiation is provided at a wavelength between about 440 nm and about 490 nm.

5. The method of claim 1 , wherein no photosensitizing agent is applied to the at least one tooth.

6. The method of claim 1 , wherein the total duration of the first and second time periods is up to about 60 minutes, and, the second time period is not greater than 5 minutes.

7. The method of claim 1 , wherein the tooth-whitening composition comprises a layer that is applied to the tooth such that the tooth-whitening composition has a peroxide density less than about 1.3 mg/cm 2 .

8. The method of claim 1 , wherein the tooth-whitening composition comprises a peroxide active having a concentration between about 7.5% and about 20% of the tooth-whitening composition.

9. The method of claim 1 , wherein the tooth-whitening composition is applied to the at least one tooth in a layer having a thickness less than about 0.3 mm.

10. The method of claim 1 , wherein the tooth-whitening composition is applied to the at least one tooth in a layer having a thickness less than about 0.2 mm.

11. The method of claim 1 , wherein the tooth-whitening composition is provided on a strip of material configured to block light waves having a frequency of greater than about 700 nm.

12. The method of claim 1 , further comprising maintaining the tooth-whitening composition on the at least one tooth for a third time period after the second time period.

13. The method of claim 1 , wherein the tooth-whitening composition does not include a photosensitizing agent.

14. A method of whitening teeth, the method consisting of:

applying to at least one tooth a layer of a translucent tooth-whitening composition comprising a peroxide dose that includes a peroxide active having a concentration between about 7.5% and about 16%, wherein a peroxide density in the layer is between about 1.3 mg/cm 2 and about 2.4 mg/cm 2 ;

maintaining the tooth-whitening composition on the at least one tooth for a first time period of about 25 minutes to about 29.5 minutes without an application of light radiation; and

after the first time period, directing a light radiation provided at a wavelength of between about 440 nm and about 490 nm and an intensity of not greater than about 45 mW/cm 2 toward the at least one tooth for a second time period of from about 0.5 minutes to about 5 minutes while the tooth-whitening composition remains upon the at least one tooth; and

removing the tooth-whitening composition from the at least one tooth.

15. A method according to claim 14 wherein the translucent tooth-whitening composition is applied to the at least one tooth from a translucent strip, and the light radiation is directed onto the tooth through the translucent strip and through the translucent tooth-whitening composition.

16. A method of whitening teeth, comprising:

applying a tooth-whitening composition as a layer having a thickness less than about 0.3 mm to at least one tooth; wherein a peroxide density in the layer is between about 1.3 mg/cm 2 and about 2.4 mg/cm 2 ;

maintaining the tooth-whitening composition on the at least one tooth for a first time period without an application of light radiation;

removing the tooth-whitening composition from the at least one tooth after the first time period; and

directing light radiation having intensity of not greater than about 150 MW/cm 2 toward the at least one tooth for a second time period,

wherein the first time period has a duration greater than 50% of a total duration of the first and second time periods.

17. The method of claim 16 , wherein the duration of the first time period is at least 80% of the total duration of the first and second time periods.

18. The method of claim 16 , wherein the light radiation is selected for absorption by a stain on the at least one tooth by selecting a wavelength corresponding to a color substantially opposite a color of the stain on the 1976 CIE LAB color scale.

19. The method of claim 16 , wherein the light radiation is provided at a wavelength between about 440 nm and about 490 nm.

20. The method of claim 16 , wherein no photosensitizing agent is applied to the at least one tooth.

21. The method of claim 20 , wherein the tooth-whitening composition is applied to the at least one tooth from a strip, and wherein the layer of the tooth-whitening composition has a thickness less than about 0.2 mm.

22. The method of claim 21 , wherein the total duration of the first and second time periods is up to about 60 minutes, and the second time period is not greater than 5 minutes.

23. A method of whitening teeth, consisting of:

applying a layer of a tooth-whitening composition including a peroxide active having a concentration greater than about 7.5% to at least one tooth, wherein a peroxide density in the layer is between about 1.3 mg/cm 2 and about 2.4 mg/cm 2 ;

maintaining the tooth-whitening composition on the at least one tooth for a first time period of about 25 minutes to about 29.5 minutes without an application of light radiation; and

after the first time period, removing the tooth-whitening composition and directing a light radiation having a wavelength between about 440 nm and about 490 nm and an intensity of not greater than about 45 mW/cm 2 toward the at least one tooth for a second time period of between about 0.5 minutes and about 5 minutes.

24. A method according to claim 23 wherein the tooth-whitening composition is applied to the at least one tooth from a strip.