Abstract:
A device provides incident light on oral structures, switchably between two states. In the first state, incident light causes autofluorescence of byproducts of decay, and an optical filter between the oral structures and either the user&#39;s eyes or a visualizing apparatus yields visually distinguishable appearances for that autofluorescence depending on whether the tissue is healthy or unhealthy. In the second state, the incident light is of a color composition that yields a substantially “white” spectrum after passing through the filter.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates generally to devices and methods for inspecting oral structures. In particular, the present invention relates to devices and methods concerning the examination of tooth surfaces, the tongue, gingivae, cheeks, interior of teeth, dentures, crowns, bridges, and any other oral structures by inducing autofluorescence, viewing it through a filter, then changing the light incident on the mouth structures to compensate for attenuation by the filter. 
       BACKGROUND 
       [0002]    In the field of dental implements, it will be appreciated that various devices may be used to detect abnormal and healthy tooth surfaces. In some instances the difference between abnormal and healthy tooth surfaces may be difficult to distinguish with the naked eye. In addition to simply identifying the abnormal and healthy tooth surfaces, it may further be difficult for a dentist of hygienist to identify where healthy tooth surfaces and abnormal surfaces begin. 
         [0003]    U.S. Pat. No. 7,813,787 describes a dental implement method for tooth surface inspection. In particular, it describes a light source body having a handle portion. The light source body includes a switch for selectively energizing and de-energizing a blue light source. The implement includes a yellow filter that is detachable from the implement body. The implement may include glasses containing the yellow filter for filtering fluorescence to be viewed. Using this disclosed implement through the yellow filter glasses, however, colors are changed and non-fluorescent examination of the mouth is impaired. 
         [0004]    While a variety of dental implements have been made and used, it is believed that no one prior to the inventor has made or used an invention as described herein. 
       SUMMARY 
       [0005]    An exemplary dental implement is shown having body with a handle and an arm. The dental implement is able to direct blue light into the mouth of a patient. The blue light is absorbed and then re-emitted by porphyrins produced by active bacteria or other abnormal structures within the intra-oral cavity. The user can then view the mouth through a filter and clearly see the porphyrins or other abnormal features as revealed by the re-emitted light. 
         [0006]    The user may then wish to view the mouth or other objects in the environment under white-light conditions and may do so without removing the filter used to visualize abnormal features by turning on a second light of the dental implement. The second light in at least some instances is directed through a second filter such that the filtered second light compensates for the first filter. As a result, the user can visualize the mouth and tooth surfaces or other objects as if under white-light conditions, yet without removal of the first filter. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    It is believed the present invention will be better understood from the following description of certain examples taken in conjunction with the accompanying drawings, in which like reference numerals identify the same elements and in which: 
           [0008]      FIG. 1  depicts a diagrammatic view of an exemplary dental implement for use with a patient; 
           [0009]      FIG. 2  depicts a graph view of the transmission spectrum of the filter  22  of  FIG. 1 ; 
           [0010]      FIG. 3  depicts a graph view of the relative intensity spectrum of the second LED  28  of 
           [0011]      FIG. 1 ; 
           [0012]      FIG. 4  depicts a graph view of the transmission spectrum of the white light filter  26  of  FIG. 1 ; 
           [0013]      FIG. 5  depicts a graph view of the relative intensity spectrum of an LED, in which the optical characteristics of the second LED  28  and white-light filter  26  are combined, transmitting substantially white light through compensating filter  22  of  FIG. 1 ; and 
           [0014]      FIG. 6  depicts a diagrammatic view of an alternative exemplary dental implement for hands-free use. 
       
    
    
       [0015]    The drawings are not intended to be limiting in any way, and it is contemplated that various embodiments of the invention may be carried out in a variety of other ways, including those not necessarily depicted in the drawings. The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention, and together with the description serve to explain the principles of the invention; it being understood, however, that this invention is not limited to the precise arrangements shown. 
       DETAILED DESCRIPTION 
       [0016]    The following description of certain examples of the invention should not be used to limit the scope of the present invention. Other examples, features, aspects, embodiments, and advantages of the invention will become apparent to those skilled in the art from this description. As will be realized, the invention is capable of other different and obvious aspects, all without departing from the invention. Accordingly, the drawings and descriptions should be regarded as illustrative and not restrictive in nature. 
         [0017]    It should be understood that, in this description, “visualization” refers to any process or means by which light or an image reaches a person&#39;s eye, whether directly or indirectly through optical elements and/or capture and display. A “path” taken by light or an image likewise may include one or more optical elements (lens, mirrors, and filters, as non-limiting examples) and elements that capture, record, and/or playback an image (e.g., CCD&#39;s, encoders, decoders, data transmission devices, display devices, and the like). Finally, a “substantially white spectrum” is defined as a spectrum that, when emitted to the eye, is perceived as white light. 
         [0018]    In examining tooth surfaces or other oral surfaces or tissues within a patient&#39;s mouth, one exemplary way of visualizing tooth surfaces includes using Quantitative Light-induced Fluorescence (“QLF”) to provide visualization of various abnormal aspects within the patient&#39;s mouth. QLF generally involves directing a light into the mouth of a patient. In many cases, the light used is a strong blue light having a peak wavelength of approximately 405 nm, though it will be appreciated that other suitable peak wavelengths could be used. Porphyrins are produced by the active bacteria in the mouth. After exposing porphyrins to the blue light, these porphyrins will fluoresce. As a result, active bacteria within the mouth may be indirectly visualized by viewing the areas of the mouth exposed to blue light. Visualization is improved with a lens or filter operable to filter out a portion of the light spectrum such that the porphyrins can be easily seen through the filter. As a result, using QLF, a user can visualize lesions, plaque, stains, or any other abnormal tooth conditions or deposits on or inside the teeth or gingiva. 
         [0019]    Generally speaking, a handheld dental implement may be used to introduce light or blue light into the mouth of the patient. The handheld dental implement may be operated by a dentist, hygienist, or other user. Furthermore, the handheld dental implement may also be used in a self-examination context where the user, perhaps with the assistance of a mirror or other suitable tool for self visualization, uses the handheld dental implement to visualize abnormal tooth surface conditions. It will be understood that in some variations, light may be applied into the mouth region of the patient using a stationary implement which could be manually, remotely, or otherwise operated by a user. While the dental implement may be used to cause areas within the mouth to fluoresce by exposing them to blue light, it will be understood that in order to survey the mouth more thoroughly, the user may also wish to view the mouth under what are effectively white-light conditions. As a result, it may be desirable for the dental implement to alternatively provide both blue light and compensated white light so that the user can switch between both lighting conditions as desired without removing the filter used for QLF. 
       I. Exemplary Dental Implement 
       [0020]    Turning now to  FIG. 1 , an exemplary dental implement  10  is shown. Generally, dental implement  10  may be used to emit a light, such as the blue light discussed above, to cause porphyrins or other relevant abnormalities to auto-fluoresce. The user aims dental implement  10  such that light is directed at oral tissues, for example, tooth surfaces of a patient&#39;s teeth  12  within the patient&#39;s mouth  11 . Dental implement  10  includes a wand having a handle portion  14  connected to an arm  16 . Arm  16  of the illustrated embodiment includes an angled rod able to deliver light to the mouth for visualization of teeth  12  along with abnormal conditions of teeth  12 . Arm  16  may define any suitable angle relative to the axis of handle portion  14  for properly positioning arm  16  within mouth  11 . It will be understood that arm  16  may include any shape including a straight rod, bendable member, knob, or any other suitable structure as would be apparent to one of ordinary skill in the art in view of the teachings herein. Handle portion  14  is shown as a cylindrical member operable to be held by a user. However, other suitable shapes may be used as well. For instance, handle portion  14  may have a contoured shape such that the user can comfortably hold handle portion  14 . 
         [0021]    Handle portion  14  of dental implement  10  in this embodiment also includes a first switch  18  that a user may actuate. Upon actuating first switch  18 , a light is emitted from dental implement  10 . In particular, in the exemplary embodiment, upon actuating first switch  18 , a first LED  24  illuminates and transmits light through arm  16 . Thereafter, the light is emitted from arm  16  into mouth  11 . Furthermore, in the exemplary embodiment shown, a blue light having a wavelength of approximately 405 nm is emitted by first LED  24 . While the illustrated embodiment uses an LED for first LED  24 , it is understood that first switch  18  may trigger a laser, OLED, bulb, or any other light-producing structure able to transmit light through arm  16  directed into mouth  11 . In addition, the embodiment shown depicts first LED  24  being positioned within handle portion  14 , but it will be understood that first LED  24  may also be located in arm  16 , on glasses wearable by the user, or in any other suitable location as would be apparent to one of ordinary skill in the art in view of the teachings herein. 
         [0022]    Arm  16  assists in directing light at the surface of teeth  12 . Upon re-actuating first switch  18 , first LED  24  turns off and blue light is no longer emitted from arm  16 . While the illustrated embodiment shows first switch  18  having a button-like construction, it will be understood that first switch  18  may include a slider switch, rotating switch, capacitive or resistive touch switch, or any other suitable switch type. Upon actuating first switch  18  and directing light onto the surface of teeth  12 , abnormal structures or substances on teeth may absorb emitted blue light. Thereafter, a portion or all of those abnormal structures or substances auto-fluoresce with intensity peaks in the green and red ranges of visible light. It will be understood that structures that auto-fluoresce due to blue light emission may be visualized as red using filter  22  positioned between mouth  11  and the eyes  30  of the user. 
         [0023]    Filter  22  includes a naked lens, but may include glasses outfitted with filter  22 . Filter  22  may be outfitted on a dental loupe or dental microscope. It will be understood that other ways of filtering particular frequencies of light may be used. In this embodiment, filter  22  filters frequencies as shown in  FIG. 2 , which will be discussed in further detail below. 
         [0024]    During the use of dental implement  10 , it will be understood that the user may wish to view the surface of teeth  12  under normal white-light conditions. Furthermore, the user may wish to alternate between white-light and blue-light views during the inspection of teeth  12  within mouth  11  without removing filter  22  from the user&#39;s line of sight. In addition to first switch  18 , which may be used to control the emission of blue light from dental implement  10 , dental implement  10  also includes a second switch  20  able to control emission of “compensated white light.” 
         [0025]    In this embodiment, second switch  20  may be actuated to illuminate a second LED  28 , which is filtered by filter  26  to emit light that, when viewed through filter  22 , is substantially white light. As discussed above with respect to first LED  24 , second LED  28  need not necessarily include an LED or only an LED. In other exemplary embodiments, second LED  28  may alternatively or additionally include a laser, OLED, bulb, or any other suitable light-emitting source. Second LED  28  is further in optical communication with compensating filter  26 . 
         [0026]    In the illustrated embodiment, dental implement  10  is shown having first switch  18  and second switch  20  positioned side by side. Indeed, other suitable configurations may be used as well. For instance, first switch  18  and second switch  20  may be implemented as a three-way switch or rocker to control the illumination of second LED  28  and first LED  24  in a single element. First switch  18  and second switch  20  may be positioned such that they rest side by side laterally rather than longitudinally along the length of handle portion  14 . First switch  18  and second switch  20  may be integrated into a touch screen or other suitable switch rather than one that mechanically actuates. Furthermore, second switch  20  may be configured such that actuating second switch  20  simultaneously turns second LED  28  on and turns first LED  24  off. 
         [0027]    Compensating filter  26  is shown as a filter located between second LED  28  and mouth  11 . Compensating filter  26  is shown in the illustrated embodiment as a lens positioned in front of second LED  28 , but it will be understood that compensating filter  26  may include other suitable variations such as a filter paint, a coating that covers second LED  28 , or a material integrally formed with second LED  28 , yet is operable to filter certain frequencies. In yet other variations, compensating filter  26  may include a “light interference filter” that intersects the light emitted by second LED  28  to filter or cancel particular wavelength ranges. As a result, compensating filter  26  in conjunction with second LED  28  is able to compensate for the effect of filter  22 . Thus, when second LED  28  is turned on, the user can look into mouth  11  through filter  22  and visualize the inside of mouth under what is effectively white-light or near white-light conditions without having to remove filter  22 . Such visualization can occur in response to the user actuating second switch  20 . 
         [0028]    In order to understand the mechanics of compensating filter  26  compensating for filter  22 , the following discusses the transmission profiles of the various filters of dental implement  10 . 
         [0029]      FIG. 2  depicts an exemplary graph  40  showing the transmission profile of exemplary filter  22 . In particular, the horizontal axis  42  shows the various wavelengths that may reach filter  22 . The vertical axis  44  shows the amount of light transmitted through filter  22  at the various wavelengths in terms of percentage transmission. Plot line  46  depicts the percentage of transmission of light at wavelengths between 400 nm and 700 nm. As can be seen from graph  40 , filter  22  is characterized by allowing almost no transmission through filter  22  at wavelengths between 400 nm and 450 nm, roughly the violet range of the visible spectrum. Filter  22  is further characterized by having a relatively low transmission rate at wavelengths between 470 nm and 600 nm, which includes the blue, green, yellow and a portion of the orange ranges of the visible spectrum. Finally, as the wavelength increases beyond 600 nm, the orange and red portions of the visible spectrum, the transmission of light through filter  22  rises to approximately 75-80%. As a result, when blue LED  24  is illuminating mouth  11 , and a user looks into mouth  11  through filter  22 , the porphyrins emit light with a strong band in the low-wavelength region and another strong band in the high-wavelength region, but the user primarily sees that decay as bright red. 
         [0030]    Turning now to  FIG. 3 , another graph  48  is shown that depicts an emission spectrum of light produced in the illustrated embodiment by second LED  28  (which was shown in  FIG. 1 ). The horizontal axis  52  depicts wavelengths between 400 nm and 700 nm. The vertical axis  54  shows the relative intensity of the light produced by the second LED  28  as a value between 0 and 100. As can be seen from plot line  50 , the relative intensity of second LED  28  peaks around 405 nm (in the violet range) and has another region of significant intensity in the wider band between 500 nm and 600 nm (mostly green and yellow). 
         [0031]      FIG. 4  shows a graph  56  of the transmission percentage of compensating filter  26  (shown in  FIG. 1 ) at wavelengths between 400 nm and 700 nm. The horizontal axis  60  shows the various wavelengths between 400 nm and 700 nm. The vertical axis  62  shows transmission percentages between 0 and 100% of compensating filter  26 . Plot line  58  shows the various transmission percentages at wavelengths between 400 nm and 700 nm. As can be seen from plot line  58 , a wider band of transmission is shown at wavelengths between 400 nm and 550 nm (violet, blue, and green). Plot line  58  then dips around wavelengths between 600 nm and 650 nm (orange and orange-red), and increases transmission at wavelengths over 650 nm (red). 
         [0032]    The composite of plot  50  (in  FIG. 3 , light emitted by second LED  28 ), plot  58  (in  FIG. 4 , transmission by compensating filter  26 ), and plot  46  (in  FIG. 2 , transmission by filter  22 ) is approximately a flat spectrum. This composite would illustrate illumination by the combination that approximates white-light illumination of mouth  11 . 
         [0033]    Finally, as an alternative to second LED  28  and compensating filter  26 ,  FIG. 5  shows a graph  64  of a compensating spectrum that represents the light spectrum emitted by a filtered LED  29 , which has a built-in filter. Filtered LED  29  produces a comparable spectral emission as the combination of second LED  28  and compensating filter  26  (shown in  FIG. 1 ), as will be understood by those skilled in the art. Similar to graph  48  shown in  FIG. 3 , graph  64  is shown in terms of relative intensity. For instance, horizontal axis  68  shows various wavelengths between 400 nm and 700 nm. Vertical axis  70  shows the relative intensity of light emitted by filtered LED  24 . Plot line  66  shows the relative intensity of filtered LED  24  at each given wavelength. 
         [0034]    As can be seen when comparing graph  40  of  FIG. 2  and graph  64  of  FIG. 5 , when the user examines a mouth using a blue light as seen through filter  22 , some distortion of the color spectrum results. Still, the user may wish to view mouth  11  as if illuminated by white light. Therefore, the user may turn on second LED  28  to shine second LED  28  through compensating filter  26  and into the mouth  11  while turning the blue light off. Light emitted by second LED  28  shines through compensating filter  26  and, as a result, compensates for portions of the light spectrum attenuated by filter  22 . Consequently, the user is able to view the area of the mouth  11  under white-light conditions without removal of filter  22  from his or her line of sight. This may be useful in instances where filter  22  is incorporated into glasses worn by the user that may be cumbersome to remove or other situations where filter  22  may not be easy to remove. 
       II. Exemplary Integrated Filter and Dental Implement 
       [0035]    It will be understood that in some instances, it may be desirable to remove the aspect of manually operating dental implement  10 .  FIG. 6  depicts an alternative version of a dental implement  110  operable to be integrated, attached, or removably attached to glasses  120 . While the illustrated embodiment shows dental implement  110  attached to glasses  120 , it will be appreciated that dental implement  110  may be attached to any suitable head-mounted object. For instance, instead of glasses  120 , dental implement  110  may be attached to a hood, helmet, visor, or any other suitable object as would be apparent to one of ordinary skill in the art in view of the teachings herein. 
         [0036]    Dental implement  110  includes first LED  24  and second LED  28  with compensating filter  26  as were discussed previously with respect to  FIG. 1 . Dental implement  110  further includes a control box  112  and power source  114 . Control box  112  may include buttons, switches, rockers, touch screens in combination with haptic feedback, foot pedals, or any other suitable actuation devices such that the user may operate dental implement  110  in a similar manner as dental implement  10  shown in  FIG. 1 . Furthermore, control box  112  may be separately attached to glasses  120  as shown in the illustrated embodiment or may alternatively be integrated with glasses  120 . For instance, control box  112  may be located or integrated with glasses  120  such that the user can readily turn on and off first LED  24  and second LED  28  to turn on the blue light and white light transmitted through compensating filter  26 . 
         [0037]    Power source  114  may include a battery, an adapter for connecting dental implement  110  into a standard outlet, or any other suitable power source as would be apparent to one of ordinary skill in the art in view of the teachings herein. Furthermore, while the illustrated embodiment shows power source  114  and control box  110  as separate structures, it will be understood that power source  114  and control box  110  may be integrated into a single device and further may be integrated into glasses  120  or otherwise removably attached to glasses  120 . 
         [0038]    It will further be understood that dental implement  110  may function in a manner substantially similar to that of dental implement  10  of  FIG. 1 . Due to dental implement  110  being attached or otherwise in communication with glasses  120 , the user can look through filter  22  at teeth  12  within mouth  11  of a patient without necessarily having to hold a second implement. Furthermore, the user may then control first LED  24  and second LED  28  to view mouth  11  under blue-light or compensating white-light conditions again without manually operating another device, thereby allowing the user to view mouth  11  through filter  22  under different lighting conditions (blue-light and/or white-light conditions) in a hands-free or substantially hands-free operation, at least with respect to dental implement  110 . 
         [0039]    In various uses, the systems and methods described herein are applied to tooth surfaces, the tongue, gingivae, cheeks, interior of teeth, dentures, crowns, bridges, and any other oral structures, as will occur to those skilled in the relevant art. 
       III. Exemplary Procedure With Dental Implement 
       [0040]    Dental implement  10  may be used in a variety of ways. For instance, in one exemplary method of use, dental implement  10  may be positioned near mouth  11 . Arm  16  may then be positioned near or within mouth  11 . The user need not necessarily have an area intended for examination. For example, the user may simply want to survey the entire mouth or alternatively may focus on a specific area for examination. The user grips and moves handle  14  to position arm  16  at an appropriate location to illuminate the desired structure or region. 
         [0041]    The user then turns on blue light by actuating first switch  18 , which illuminates first LED  24 . First LED  24  shines a blue light through arm  16  and into mouth  11 . Porphyrins or other abnormal structures fluoresce, and that fluorescence can be seen by the user&#39;s eyes  30  looking through filter  22 . Thereafter, if the user wishes to view inside of mouth  11  or areas of teeth  12  under white-light conditions, the user actuates second switch  20 . Actuating second switch  20  extinguishes first LED  24  and illuminates second LED  28 , shining light through compensating filter  26  to produce compensated white light. As a result, the user can view mouth  11  and teeth  12  as if under white light without a filter, yet without having to remove filter  22 . If the user wishes to return to visualizing mouth  11  and teeth  12  under a filtered blue-light view, then the user can actuate second switch  20  again to turn off second LED  28 . First switch  18  may be actuated again in order to turn off blue light emitted by first LED  24 . 
         [0042]    In various alternative embodiments, filter  22  is made integral to arm  16  or body  14 , while in others it is separate or separable, and in still others it is reattachable. In some alternative embodiments, separate light sources produce the blue light and compensated white light, while in others the two kinds of light are produced by a single light source that is selectably filtered and/or selectably energizes one or more filaments or other light-producing structures. 
         [0043]    Having shown and described various embodiments of the present invention, further adaptations of the methods and systems described herein may be accomplished by appropriate modifications by one of ordinary skill in the art without departing from the scope of the present invention. Several of such potential modifications have been mentioned, and others will be apparent to those skilled in the art. For instance, the examples, embodiments, geometrics, materials, dimensions, ratios, steps, and the like discussed above are illustrative and are not required. Accordingly, the scope of the present invention should be considered in terms of any claims that may be presented and is understood not to be limited to the details of structure and operation shown and described in the specification and drawings. 
         [0044]    Furthermore, the attached Appendix is merely exemplary and does not necessarily limit the scope of the present invention to any particular embodiment shown in the Appendix. It will be understood that such embodiments in the attached Appendix are merely illustrative.