Surgical treatment method and instrument

• US 5,020,995 A
• Filed: 01/18/1989
• Issued: 06/04/1991
• Est. Priority Date: 01/18/1989
• Status: Expired due to Term

• Current Assignee: Endo Technic International Corporation
• Original Assignee: Guy Levy
• Inventors: Levy, Guy
• Primary Examiner(s): Stone, Cary E.
• Application Number:
  US07/299,472
• Time in Patent Office: 867 Days
• Field of Search: 433/215, 433/216, 606/3, 606/10, 606/15, 606/16
• US Class Current: 433/215
• CPC Class Codes: A61B 2017/00185 Means for setting or varying the pulse height
• CPC Class Codes: A61B 2017/22085 light-absorbing A61B2017/22087 takes precedence
• CPC Class Codes: A61B 2018/2272 with reflective or refractive surfaces for deflecting the beam A61B2018/2261, A61B2018/2266 take precedence
• CPC Class Codes: A61C 1/0046 Dental lasers surgical lasers A61B18/20; working by laser beam in general B23K26/00; lasers per se H01S3/00
• CPC Class Codes: A61M 3/0279 Cannula; Nozzles; Tips; their connection means
• CPC Class Codes: B23K 2103/30 Organic material
• CPC Class Codes: B23K 26/0006 taking account of the properties of the material involved B23K26/32, B23K26/40 take precedence
• CPC Class Codes: B23K 26/144 the fluid stream containing particles, e.g. powder

Abstract

A method and apparatus for cutting tooth tissue by generating laser radiation at a wavelength which is absorbed more strongly by hydroxyapatite than by water; producing a succession of pulses of the generated radiation with an energy level, pulse duration, and repetition rate selected to cut the tooth tissue without causing harmful side effects; and concentrating the radiation pulses on the tissue to a spot sufficiently small to cause cutting of the tissue.

Claims

1. A method for cutting tooth tissue comprising:

imparting a dark coloration to the tooth tissue at a location where the tissue is to be cut;

generating laser radiation at a wavelength which is absorbed more strongly by hydroxyapatite than by water;

producing a succession of pulses of the generated radiation with an energy level, pulse duration, and repetition rate selected to cut the tooth tissue without causing harmful side effects; and

concentrating the radiation pulses on the tissue at the location of the dark coloration and to a spot sufficiently small to cause cutting of the tissue.

2. A method as defined in claim 1 wherein the wavelength of the radiation is 1.06 μ

.

3. A method as defined in claim 1 wherein each pulse applied to the tissue has an energy content of between about 10 and 50 mJ.

4. A method as defined in claim 3 wherein each pulse applied to the tissue has an energy content of between about 20 and 50 mJ.

5. A method as defined in claim 1 wherein said step of concentrating is carried out to limit the radiation to a spot having a diameter not exceeding about 250 μ

.

6. A method as defined in claim 5 wherein the spot has a diameter of between about 200 and 600 μ

.

7. A method as defined in claim 1 wherein the pulses have a repetition rate of the order of 50 Hz.

8. A method as defined in claim 1 wherein the pulses have a duration of about 100-300 μ

sec.

9. A method as defined in claim 1 wherein the tooth tissue to be cut is healthy dentin.

10. A method as defined in claim 9 wherein said step of imparting comprises applying a black substance to the dentin.

11. A method as defined in claim 9 wherein the wavelength of the radiation is 1.06 μ

.

12. A method as defined in claim 1 further comprising supplying a cooling fluid to the region of the spot simultaneously with said concentrating step.

13. A method as defined in claim 12 wherein the fluid is water.

14. Apparatus for cutting tooth tissue comprising:

means including an Nd YAG laser for generating laser radiation at a wavelength which is absorbed more strongly by hydroxyapatite than by water;

means connected to said generating means for causing said generating means to produce a succession of pulses of the generated radiation with an energy level, pulse duration, and repetition rate selected to cut the tooth tissue without causing harmful side effects; and

an exposed optical fiber disposed for concentrating the radiation on the tissue to a spot sufficiently small to cause cutting of the tissue said optical fiber having a diameter sufficiently small and a length sufficient to permit insertion of said fiber into a tooth canal.

15. Apparatus as defined in claim 14 wherein the wavelength of the radiation is between 0.5 and 1.1 μ

.

16. Apparatus as defined in claim 15 wherein the wavelength of the radiation is about 0.532 and μ

.

17. Apparatus as defined in claim 15 wherein the wavelength of the radiation is about 106 μ

.

18. Apparatus as defined in claim 14 further comprising means disposed for supplying a cooling fluid to the region of the spot simultaneously with application of the radiation.

19. A method for cutting vascularized tissue comprising:

generating radiation by means of an Nd YAG laser;

acting on the radiation produced by the laser in a manner to double its frequency;

producing a succession of pulses of the frequency doubled radiation with an energy level, pulse duration and repetition rate selected to cut the tissue without causing harmful side effects; and

concentrating the radiation pulses on the tissue to a spot sufficiently small to cause cutting of the tissue.

20. A method as defined in claim 19 wherein each pulse applied to the tissue has an energy content of not greater than about 10 mJ.

21. A method for cutting tooth tissue comprising generating radiation by means of a NdYAG Laser;

producing a succession of pulses of the generated radiation with an energy level, pulse duration, and repetition rate selected to cut the tooth tissue without causing harmful side effects;

concentrating the radiation pulses on the tissue to a spot sufficiently small to cause cutting of the tissue; and

supplying a cooling fluid to the tissue at the location of application of the radiation pulses.

22. A method for cutting tooth dentin comprising:

generating laser radiation at a wavelength which is absorbed more strongly by hydroxyapatite than by water;

producing a succession of pulses of the generated radiation with an energy level, pulse duration, and repetition rate selected to cut tooth dentin without causing harmful side effects; and

concentrating the radiation pulses on tooth dentin to a spot sufficiently small to cause cutting of the dentin.

25. A method as defined in claim 22, further comprising imparting a dark coloration to the dentin at the location where the dentin is to be cut prior to said step of concentrating the radiation pulses.

26. A method as defined in claim 22 wherein the laser radiation is generated by an Nd:

YAG laser.

23. A method as defined in 22 further comprising:

supplying a cooling fluid to the dentin at the location of application of the radiation pulses.

24. A method as defined in claim 23 where the cooling fluid is water.

27. A method for removing tissue from the walls of a tooth canal comprising:

generating laser radiation at a wavelength which is absorbed more strongly by hydroxyapatite than by water, the laser radiation being in the form of a succession of pulses with an energy level, pulse duration and repetition rate selected to cut the tissue;

introducing an optical fibre into the tooth canal;

and delivering the laser radiation to the wall of the tooth canal via the optical fibre.