Methods for determing optical characteristics including subsurface characteristics of dental objects using first and second light source-receiver pairs and first and second critical heights

• US 7,139,068 B2
• Filed: 10/24/2005
• Issued: 11/21/2006
• Est. Priority Date: 06/30/1998
• Status: Expired due to Fees

• Current Assignee: RPX Corporation
• Original Assignee: JJL Technologies, L.L.C.
• Inventors: Jung, Wayne D., Jung, Russell W., Loudermilk, Alan R.
• Primary Examiner(s): Toatley, Gregory
• Assistant Examiner(s): MERLINO, AMANDA H
• Application Number:
  US11/257,625
• Publication Number:
  US 20060050264A1
• Time in Patent Office: 393 Days
• Field of Search: 356445-446, 356416-420, 356/402, 356/73, 433/29, 433/26, 433/203.1
• US Class Current: 356/73
• CPC Class Codes: A61B 5/0088 for oral or dental tissue
• CPC Class Codes: G01J 2003/1217 Indexed discrete filters or choppers
• CPC Class Codes: G01J 2003/1234 Continuously variable IF [CVIF]; Wedge type
• CPC Class Codes: G01J 2003/468 of objects containing fluorescent agent
• CPC Class Codes: G01J 3/02 Details
• CPC Class Codes: G01J 3/0208 using focussing or collimating elements, e.g. lenses or mirrors; performing aberration correction
• CPC Class Codes: G01J 3/0218 using optical fibers
• CPC Class Codes: G01J 3/0229 using masks, aperture plates, spatial light modulators or spatial filters, e.g. reflective filters
• CPC Class Codes: G01J 3/0264 Electrical interface; User interface
• CPC Class Codes: G01J 3/0272 Handheld
• CPC Class Codes: G01J 3/0278 Control or determination of height or angle information for sensors or receivers
• CPC Class Codes: G01J 3/0283 using a charging unit
• CPC Class Codes: G01J 3/0291 Housings; Spectrometer accessories; Spatial arrangement of elements, e.g. folded path arrangements
• CPC Class Codes: G01J 3/463 Colour matching
• CPC Class Codes: G01J 3/508 measuring the colour of teeth
• CPC Class Codes: G01J 3/51 using colour filters
• CPC Class Codes: G01J 3/513 having fixed filter-detector pairs
• CPC Class Codes: G01J 3/524 Calibration of colorimeters
• CPC Class Codes: G01N 21/251 Colorimeters; Construction thereof
• CPC Class Codes: G01N 21/474 Details of optical heads therefor, e.g. using optical fibres
• CPC Class Codes: G01N 21/57 : Measuring gloss

Abstract

Optical characteristic measuring systems and methods such as for determining the color or other optical characteristics of teeth are disclosed. Perimeter receiver fiber optics are spaced apart from a source fiber optic and receive light from the surface of the object/tooth being measured. Light from the perimeter fiber optics pass to a variety of filters. The system utilizes the perimeter receiver fiber optics to determine information regarding the height and angle of the probe with respect to the object/tooth being measured. Under processor control, the optical characteristics measurement may be made at a predetermined height and angle. Various color spectral photometer arrangements are disclosed. Translucency, fluorescence, gloss and/or surface texture data also may be obtained. Audio feedback may be provided to guide operator use of the system. The probe may have a removable or shielded tip for contamination prevention. A method of producing dental prostheses based on measured data also is disclosed. Measured data also may be stored and/or organized as part of a patient data base.

Claims

1. A method for determining optical characteristics of a dental object comprising the steps of:

positioning a probe substantially in contact with the object, wherein the probe provides light to the object from one or more light sources and receives light from the object through one or more light receivers, wherein received light is transmitted to a measurement device for measurement, wherein the one or more light sources and the one or more light receivers have numerical apertures and positioning relative to each other to define at least first and second light source-light receiver pairs having first and second critical heights, respectively, below which light reflected from a surface of the object is not transmitted to the measurement device for measurement, wherein the first critical height is different from the second height;

measuring optical properties of light received and transmitted to the measurement device, wherein a first measurement is taken based on the first light source-light receiver pair having the first critical height and a second measurement is taken based on the second light source-light receiver pair having the second critical height; and

determining optical characteristics of the object based on the first and second measurements, wherein the optical characteristics of the object include optical characteristics of one or more subsurface characteristics of the object.

2. The method of claim 1, wherein the optical characteristics comprise color characteristics and translucence characteristics.

3. The method of claim 1, wherein the optical characteristics include information indicative of internal scattering and thickness of a layer of the object.

4. The method of claim 3, wherein the layer comprises an enamel layer.

5. The method of claim 1, wherein the probe comprises a plurality of light sources.

6. The method of claim 5, wherein the optical characteristics are measured through a barrier, wherein the barrier has a thickness that is less than the first height and the second height.

7. The method of claim 1, the method further comprises the steps of:

measuring optical characteristics of a set of materials that will be used to produce one or more prosthetic dental objects;

storing data based on the measured optical characteristics of the set of materials;

after measurement of the optical characteristics of the object, outputting data for preparing at least a first prosthetic dental object, wherein the output data is based on the stored data.

8. The method of claim 7, wherein the optical characteristics comprise color characteristics and translucence characteristics, wherein the output data comprises a formula or recipe for producing the first prosthetic dental object, wherein the formula or recipe is a function of the measured optical characteristics of the dental object and the measured optical characteristics of the set of materials.

9. The method of claim 1, further comprising the steps of:

selectively adding or removing material to or from the object;

measuring optical characteristics of the object; and

performing the selectively adding or removing step and the measuring step until an object of desired optical characteristics or one or more acceptance criteria are satisfied.

10. The method of claim 9, wherein the optical characteristics comprise color characteristics and translucence characteristics.

11. A method for determining optical characteristics of a dental object comprising the steps of:

providing light to the object and receiving light from the object via a fiber optic probe substantially in contact with the object, wherein received light is transmitted to a measurement device for measurement, wherein the fiber optic probe includes a central fiber optic and a plurality of fiber optics spaced apart from the central fiber optic, wherein the fiber optics include one or more light source fiber optics and one or more light receiver fiber optics, wherein the one or more light source fiber optics and the one or more light receiver fiber optics have numerical apertures and positioning relative to each other to define at least first and second light source-light receiver pairs having first and second critical heights, respectively, below which light reflected from a surface of the object is not transmitted to the measurement device for measurement, wherein the first critical height is different from the second height;

measuring optical properties of light received and transmitted to the measurement device, wherein a first measurement is taken based on the first light source-light receiver pair having the first critical height and a second measurement is taken based on the second light source-light receiver pair having the second critical height; and

determining optical characteristics of the object based on the first and second measurements, wherein the optical characteristics of the object include optical characteristics of one or more subsurface characteristics of the object.

12. The method of claim 11, wherein the optical characteristics comprise color characteristics and translucence characteristics.

13. The method of claim 11, wherein the optical characteristics include information indicative of internal scattering and thickness of a layer of the object.

14. The method of claim 13, wherein the layer comprises an enamel layer.

15. The method of claim 11, wherein the probe comprises a plurality of light sources.

16. The method of claim 15, wherein the optical characteristics are measured through a barrier, wherein the barrier has a thickness that is less than the first height and the second height.

17. The method of claim 11, the method further comprises the steps of:

measuring optical characteristics of a set of materials that will be used to produce one or more prosthetic dental objects;

storing data based on the measured optical characteristics of the set of materials;

after measurement of the optical characteristics of the object, outputting data for preparing at least a first prosthetic dental object, wherein the output data is based on the stored data.

18. The method of claim 17, wherein the optical characteristics comprise color characteristics and translucence characteristics, wherein the output data comprises a formula or recipe for producing the first prosthetic dental object, wherein the formula or recipe is a function of the measured optical characteristics of the dental object and the measured optical characteristics of the set of materials.

19. The method of claim 11, further comprising the steps of:

selectively adding or removing material to or from the object;

measuring optical characteristics of the object; and

performing the selectively adding or removing step and the measuring steps until an object of desired optical characteristics or one or more acceptance criteria are satisfied.

20. The method of claim 19, wherein the optical characteristics comprise color characteristics and translucence characteristics.