Method and means for exerting a phototoxic effect of visible light on microorganisms

1. A selective photochemical method of treating microbial diseases in local infections by selectively damaging specific bacteria, said method comprising step of emitting for a time period of up to 3 minutes a beam of a blue light towards the tissue to be treated; said beam of a blue light characterized by (i) wavelength from 400 to 550 nanometers; (ii) energy density in the range of 0.5 to 234 J/cm 2 ; thereby forming reactive oxygen species (ROS) and selectively damaging said specific bacteria;

said energy density is provided such that an irreversible thermal damage to said tissue during and after said step of emitting blue light is prevented;

wherein said step of emitting said blue light beam is performed without (i) any exogenous photosensitizers; and, (ii) any thermal coagulation of said bacteria.

2. The selective method according to claim 1 , wherein the local infections are selected from the body cavities, interfaces, ear, nose, throat, vagina or orifices; and further wherein the microbial diseases are selected from bacterial, viral or fungal diseases.

3. The selective method according to claim 1 , useful for inhibiting predetermined bacteria from growing into biofilm such that periodontitis is prevented.

4. The selective method according to claim 1 , useful for inhibiting predetermined anaerobic microorganisms from growing into biofilm such that periodontitis is prevented.

5. The selective according to claim 1 , wherein said bacteria is anaerobic bacteria selected from a group consisting of F. nucleatum, P. gingivalis or any other anaerobic bacteria.

6. The selective method according to claim 1 , wherein said method is useful for treating periodontal pathologies, peri-implantitis, mechano-blistering diseases or abscess.

7. The selective method according to claim 1 , useful for exerting photochemical effect in root canals.

8. The selective method according to claim 1 , wherein said step of emitting said blue light is performed in different fluences.

9. The selective method according to claim 1 , wherein said blue light beam is emitted in a series of pulses.

10. The selective method according to claim 1 , additionally comprising steps of:

emitting a plurality of light beams having a wavelength from 400 to 550 nanometers towards the tissue to be treated; and,

emitting a plurality of light beams having a wavelength from 280 to 850 nanometers towards said tissue such that a photochemical effect is exerted.

11. The selective method according to claim 10 , wherein either the blue or other light beams are emitted in different fluences.

12. The selective method according to claim 10 , wherein the two light beams are emitted concurrently, in a series, continuously, in pulses, or any combination thereof

13. The selective method according to claim 1 , wherein said method additionally comprising the step of introducing a chemical cofactor prior, concurrent or after the blue light emission.

14. The selective method according to claim 13 , wherein said chemical cofactor is selected from a group consisting of oxygen donor; medicament; cationic agent or any combination thereof.

15. The selective method according to claim 14 , wherein said oxygen donor is selected from a group consisting of hydrogen peroxide; singlet oxygen; deuterium oxide; hydroxyl radical; superoxide anion or any combination thereof.

16. The selective method according to claim 14 , wherein said oxygen donor is ozone.

17. The selective method according to claim 14 , wherein said medicament is selected from a group a group consisting of antibiotic compositions, antimicrobial agents, vasoconstrictors; or any combination thereof.

18. The selective method according to claim 1 , additionally comprising applying ultrasonic vibration prior, concurrent or after said step of emitting light.

19. The selective method according to claim 1 , wherein said bacteria is anaerobic bacteria; further wherein said selectively, damaging said specific kind of bacteria, is regulated by varying said energy densities delivered to said tissue.

20. The selective method according to claim 1 , wherein said bacteria is anaerobic bacteria; further wherein said selectively, damaging said specific kind of bacteria, is regulated by varying the concentration of ROS.

21. A photochemical method for reducing the flora of microbial pathogens in local infections, said method comprising steps of:

emitting for a time period of up to 3 minutes a beam of a blue light towards the tissue to be treated; said beam characterized by (i) wavelength from 400 to 550 nanometers; (ii) fluence in the range of 0.5 to 234 J/cm 2 ; thereby forming reactive oxygen species (ROS) and damaging said flora;

said energy density is provided such that an irreversible thermal damage to said tissue during and after said step of emitting blue light is prevented; and,

b. introducing an oxygen donor to said tissue such that all said flora is significantly damaged;

wherein said step (a) of emitting said blue light beam is utilized without any exogenous photosensitizers such that (i) a photochemical effect is exerted; and, (ii) no thermal coagulation of said flora is obtained.

22. The method according to claim 21 , additionally comprising step of regulating the damage to said flora by varying said energy densities delivered to said tissue.

23. The method according to claim 21 , additionally comprising step of regulating the damage to said flora by varying the concentration of ROS.