Methods for whitening teeth

1. A method of whitening teeth, comprising:

applying a whitening composition as a layer having a thickness less than about 0.3 mm to at least one tooth;

maintaining the 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 while the whitening composition remains upon 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; and

removing the whitening composition from the at least one tooth; wherein the whitening composition is translucent and is applied to said at least one tooth by a translucent strip or tray, and wherein said light radiation is directed toward said tooth through said translucent strip or tray and through said translucent whitening composition;

and wherein the radiation intensity is no greater than about 150 mW/cm 2 .

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 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 no greater than 5 minutes.

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

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

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

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

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

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

13. A method of whitening teeth, consisting of:

applying a translucent whitening composition including a peroxide active having a concentration between about 7.5% and about 20% to at least one tooth in a layer having a thickness less than about 0.3 mm and a peroxide density less than about 1.3 mg/cm 2 ;

maintaining the 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 between about 440 nm and about 490 nm and an intensity of no greater than about 45 mW/cm 2 toward the at least one tooth for a second time period of about 0.5 minutes to about 5 minutes while the whitening composition remains upon the at least one tooth;

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

14. A method according to claim 13 wherein the translucent whitening composition is applied to said at least one tooth from a translucent strip, and the light radiation is directed onto said tooth through said translucent strip and through said translucent composition.

15. A method of whitening teeth, comprising:

applying a whitening composition as a layer having a thickness less than about 0.3 mm to at least one tooth;

maintaining the 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 removing the whitening composition from the at least one tooth, and directing 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 radiation intensity is no greater than about 150 MW/cm 2 .

16. The method of claim 15 , wherein the duration of the first time period is at least 80% of the total duration of the first and second time periods.

17. The method of claim 15 , 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.

18. The method of claim 15 , wherein the light radiation is provided at a wavelength between about 440 nm and about 490 nm.

19. The method of claim 15 , wherein no photosensitizing agent is applied to the at least one tooth.

20. The method of claim 15 , wherein the whitening composition comprises a layer that is applied to the tooth such that the whitening composition has a peroxide density less than about 1.3 mg/cm 2 .

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

22. The method of claim 21 , wherein the whitening composition is applied to the at least one tooth from a strip, said composition being in a layer having a thickness less than about 0.2 mm.

23. The method of claim 22 , wherein the total duration of the first and second time periods is up to about 60 minutes, and the second time period is no greater than 5 minutes.

24. A method of whitening teeth, consisting of:

applying a whitening composition including a peroxide active having a concentration between about 7.5% and about 20% to at least one tooth in a layer having a thickness less than about 0.3 mm and a peroxide density less than about 1.3 mg/cm 2 ;

maintaining the 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 said whitening composition and directing a light radiation provided at a wavelength between about 440 nm and about 490 nm and an intensity of no greater than about 45 mW/cm 2 toward the at least one tooth for a second time period of about 0.5 minutes to about 5 minutes.

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