Infrared dental imaging

Abstract

Dental imaging systems include an optical scanner that scans one or more interrogation beams across a portion of at least one tooth to produce a dentally modulated light flux associated with light scattering, absorption, or other interaction of the interrogation beam and a tooth interior. The dentally modulated light flux is detected and processed to produce picture information associated with the tooth. Interrogation wavelengths between 800 nm and 1800 nm can be used to provide images suitable for diagnosis and assessment of demineralization or other defects. Interrogation beams at one or more wavelengths can be used. Multiple detectors can be situated to receive dentally modulated light fluxes at different wavelengths or dentally modulated light fluxes with different directions or different locations. Markers at or on a tooth can be used to for depth determination. Index matching to the tooth can improve image quality.

I claim: 
     
         1 . A dental transillumination imaging system, comprising:
 a light source that directs light into at least one tooth;   light-coupling material operable to contact and conform to a surface of the tooth, the light-coupling material substantially transparent to the light and having an index of refraction that is closer to the index of the tooth than the index of air is to the tooth;   a detection device that detects light emerging from a region of the at least one tooth that differs from a region at which the light enters the tooth, wherein at least one or both of the light source and the detection device are situated so that the light emerging from the tooth and received by the detection device has been transmitted by the light-coupling material; and   an imaging system coupled to the detection device and operable to create a viewable picture based on the light detected by the detection device.   
     
     
         2 . The dental imaging system of  claim 1 , wherein the light-coupling material is situated between the light source and the at least one tooth so that the light is directed to the at least one tooth by transmission through the light-coupling material. 
     
     
         3 . The dental imaging system of  claim 1 , wherein the light-coupling material is situated between the detection device and the at least one tooth so that the light emerging from the tooth is transmitted by the light-coupling material to the detection device. 
     
     
         4 . The dental imaging system of  claim 1 , wherein the light has a wavelength or a range of wavelengths greater than about 800 nm. 
     
     
         5 . The dental imaging system of  claim 1 , wherein the light source includes a laser diode. 
     
     
         6 . The dental imaging system of  claim 1 , wherein the light source includes a light emitting diode. 
     
     
         7 . The dental imaging system of  claim 1 , wherein the light-coupling material comprises a fluid or a gel. 
     
     
         8 . The dental imaging system of  claim 1 , wherein the light-coupling material comprises a flexible solid material. 
     
     
         9 . The dental imaging system of  claim 1 , wherein the light-coupling material is situated between the detection device and the tooth and the light source and the tooth so that the light is directed to the at least one tooth by transmission through the light-coupling material and the light emerging from the tooth is transmitted by the light-coupling material to the detection device. 
     
     
         10 . A dental transillumination method, comprising:
 directing light into at least one tooth at a first tooth region;   applying a light-coupling material so as to conform to a surface portion of the at least one tooth, wherein the light coupling material is transmissive to the light;   detecting a portion of the light emerging from a second tooth region that differs from the first tooth region, wherein the surface portion of the tooth is situated so that the light is directed into the first tooth region through the light-coupling material or the light emerging from the second tooth region is transmitted by the light-coupling material prior to the detecting; and   forming a viewable picture of at least a portion of the at least one tooth based on the detected portion of the light emerging from the at least one tooth.   
     
     
         11 . The dental transillumination method of  claim 10 , wherein the surface portion of the at least one tooth is situated so that the light is directed into the first tooth region through the light-coupling material. 
     
     
         12 . The dental transillumination method of  claim 10 , wherein the light-coupling material is situated so that the light emerging from the second tooth region is transmitted by the light-coupling material. 
     
     
         13 . The dental transillumination method of  claim 10 , wherein the light has a wavelength or a range of wavelengths greater than about 800 nm. 
     
     
         14 . The dental transillumination method of  claim 10 , wherein the light is provided with a laser diode. 
     
     
         15 . The dental transillumination method of  claim 10 , wherein the light is provided with a light emitting diode. 
     
     
         16 . The dental transillumination method of  claim 10 , wherein the light-coupling material comprises a fluid or a gel. 
     
     
         17 . The dental transillumination method of  claim 10 , wherein the light-coupling material comprises a flexible solid material. 
     
     
         18 . The dental transillumination method of  claim 10 , wherein the surface portion of the tooth is situated so that the light is directed into the first tooth region through the light-coupling material and the light emerging from the second tooth region is transmitted by the light-coupling material prior to the detecting. 
     
     
         19 . A system, comprising:
 means for directing an illumination light into a tooth at a first region;   light-coupling means operable to contact and conform to a surface of the tooth, wherein the light-coupling means is substantially transparent to the illumination light;   a detection means situated to detect a portion of the illumination light emerging from a second region of the tooth that differs from the first region of the tooth, wherein the light-coupling means is situated to transmit the illumination light into the tooth at the first region, to transmit the illumination light from the second region to the detection means, or to transmit the illumination light into the tooth at the first region and transmit the illumination light from the second region to the detection means; and   means for imaging coupled to the detection means and operable to create a viewable picture based on the detected portion of the illumination light.   
     
     
         20 . The system of  claim 19 , wherein the light-coupling means is situated to transmit the illumination light from the second region to the detection means.