Dental procedures and apparatus using ultraviolet radiation

• US 5,968,036 A
• Filed: 04/08/1998
• Issued: 10/19/1999
• Est. Priority Date: 03/04/1993
• Status: Expired due to Term

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Wynne, James Jeffrey, Goodman, Barry Dean, Jacobs, Jason Matthew, Kaufman, Hershall William
• Primary Examiner(s): PEFFLEY, MICHAEL F
• Application Number:
  US09/057,304
• Time in Patent Office: 559 Days
• Field of Search: 606/2, 606/3, 606/10-17, 433/215, 607/89
• US Class Current: 606/12
• CPC Class Codes: A61B 17/24 for use in the oral cavity, larynx, bronchial passages or nose for medical inspection of cavities or tubes in the body A61B1/00; Tongue scrapers
• CPC Class Codes: A61B 18/20 using laser
• CPC Class Codes: A61B 18/201 with beam delivery through a hollow tube, e.g. forming an articulated arm through a flexible conduit A61B18/22; Hand-pieces therefor
• CPC Class Codes: A61B 2017/00022 Sensing or detecting at the treatment site
• CPC Class Codes: A61B 2017/00128 related to intensity or progress of surgical action
• CPC Class Codes: A61B 2018/00636 Sensing and controlling the application of energy
• CPC Class Codes: A61B 2218/008 for smoke evacuation
• 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: B23K 26/03 Observing, e.g. monitoring, the workpiece
• CPC Class Codes: B23K 26/032 using optical means

Abstract

An improved dental procedure and apparatus where ultraviolet radiation pulses are used to etch selectively both hard tissue and soft tissue in dental procedures. There exists distinct ablation thresholds for hard and soft tissue which are dependent on the material being ablated for a given wavelength of the ultraviolet radiation. Sufficient differences in ablation threshold exist for enamel, dentin, and carious material, thereby allowing dentists to perform both hard tissue and soft tissue procedures without excess damage to healthy enamel, dentin or other pulp structures.

Claims

1. An apparatus for performing laser dentistry on a tooth in a patient'"'"'s mouth, comprising:

a laser system for producing ultraviolet radiation pulses,

delivery means for delivering said radiation pulses to said tooth to ablate material therefrom without substantial heat buildup at said tooth, and

control means for automatically controlling the energy fluence of said ultraviolet radiation pulses to selected energy fluences in accordance with the type of material being ablated from said tooth, a first selected energy fluence being at least the threshold fluence F₁ necessary to ablate enamel at a selected ultraviolet wavelength, and a second selected energy fluence being greater than the threshold fluence F₂ necessary to ablate carious material but less than the fluence F₁, at said selected ultraviolet wavelength.

2. The apparatus of claim 1, where said control means includes sensor means for detecting the type of tooth material to be ablated and feedback means to provide a signal to said control means, said control means then regulating said laser system to provide ultraviolet radiation pulses having either said first or second selected energy fluence.

3. The apparatus of claim 1, where said control means can control the energy fluence of said ultraviolet radiation pulses to a third selected energy fluence greater than the threshold F₃ necessary to ablate dentin but less than the fluence F₂.

4. The apparatus of claim 1, where said selected ultraviolet wavelength is in the range of about 185-220 nm.

5. The apparatus of claim 1, where said selected ultraviolet wavelength is in the range of about 300-400 nm.

6. The apparatus of claim 1, including means for automatically changing the energy fluence of said ultraviolet radiation pulses between said first and second selected energy fluences during laser ablation of said teeth.

7. The apparatus of claim 1, including means for automatically changing the repetition rate of said ultraviolet radiation pulses during laser ablation of said tooth.

8. The apparatus of claim 1, including means for sensing the presence of harmful biological material in the patient'"'"'s mouth and means for automatically decreasing the energy fluence of said ultraviolet radiation pulses to an energy fluence level that is insufficient to ablate material from said tooth.

9. The apparatus of claim 6, where said selected ultraviolet wavelength is in the range 185-220 n or 300-400 nm.

10. The apparatus of claim 1, where said first selected energy fluence is at least about 5.8 J/cm² and said second selected energy fluence is greater than about 1.36 J/cm² and less than about 5.8 J/cm².

11. The apparatus of claim 10, where said selected ultraviolet wavelength is in the range 18.5-220 nm or 300-400 nm.

12. The apparatus of claim 11, where said laser system includes a solid state laser.

13. The apparatus of claim 12, where said delivery means includes an optical fiber for transmitting said ultraviolet radiation pulses to said tooth.

14. The apparatus of claim 13, including a sensor located near the tip of said optical fiber, said sensor producing a signal indicative of the type of material to be ablated from said tooth.