Abstract:
A dental mirror tool having a body comprises a manifold disposed on the tool body proximate the mirror, a plurality of output ports disposed in an outlet side of the manifold and disposed to emit streams of light and fluid and air or suction toward a predetermined target, and a selection system for selecting the light, fluid, or air or suction emitted toward the predetermined target. In another aspect, a method for directing streams of light, fluid, air, or suction toward a target during a dental procedure, comprising the steps of attaching a manifold having output orifices for light, fluids, air, or suction to a body of the tool; connecting the orifices to sources of light, fluid, air, or suction; and controlling a substance emitted from the orifices to be directed toward the target.

Description:
1. CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    The present application claims priority from Provisional Application Ser. No. 61/366,433, filed Jul. 21, 2010, entitled “Multipurpose Dental Instrument” by inventor, Jackelyne Rodriquez (Moreno). 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    2. Field of the Invention 
         [0003]    The present invention generally relates to dental equipment and more specifically to handheld dental instruments for illumination, viewing, and cleaning a patient&#39;s teeth. 
         [0004]    3. Background of the Invention and Description of the Prior Art 
         [0005]    Conventional instruments or implements for use in dental care include mirrors, lamps, compressed air jets, and water jets or hydrants. Dental mirrors are typically small, round mirrors attached at an angle to the end of an elongated rod-like handle. The angle of the mirror with the handle may typically be in the range of 20 to 60 degrees relative to the longitudinal axis of the elongated handle. Such placement facilitates the dentist or assistant&#39;s observation of a patient&#39;s upper teeth while standing or seated in an erect position, thus minimizing possible discomfort and awkward viewing angles. 
         [0006]    Compressed air and water jets are each typically provided as separate implements because they are supplied from different reservoirs, the compressed air from an air compressor and storage tank for example, and the water from a water pump and storage tank. Both air and water supplies are fed via a hose connected to the respective storage tank, and a hand held control handle or foot-operated control. Illumination of a patient&#39;s mouth is provided by a specialized overhead lamp fixture attached to a gimble assembly supported by a counterbalanced and articulated arm that may be positioned at will by the dentist or dental assistant. The lamp may be equipped with a lens to minimize scattered light and to focus the light on the work area of interest. 
         [0007]    There are a number of disadvantages to this configuration of the dental instruments, both to the dentist and the patient. In many cases an assistant is required to hold and manipulate one or more of the dental implements while the dentist is at work performing dental treatment of or repair to a patient&#39;s teeth. In civilian or military field treatment, outside a dentist&#39;s office, handling the necessary implements can be even more awkward and cumbersome because they cannot easily supported or held except by the dental personnel themselves. For example, the dentist may need to manipulate simultaneously a drilling apparatus and a mirror, while an assistant manipulates a stream of water or air at the dentist&#39;s instruction. Illumination from a suspended lamp may provide the necessary light; however, to ensure maximum light upon the work area often requires that the hands and implements in use be positioned so as not to create shadows in the area of interest. Such positioning may require awkward, uncomfortable, or less than optimum orientation of the other implements to avoid blocking the light. Further, up to four hands may be in close, possibly interfering positions in order to properly manipulate the implements for a particular operation, resulting in compromised positioning, making the performance of the operation less efficient and more cumbersome, thus prolonging the time to perform the operation and increased discomfort to the patient. 
         [0008]    Other disadvantages include, obviously, the discomfort to the patient due to the plurality of hardware implements positioned in and moving around in the patient&#39;s mouth. Further, the more such implements, the more widely opened the lower jaw of the patient must be, which often tends to increase the discomfort experienced by the patient. Moreover, the procedural steps performed by the dental personnel must be designed or modified to overcome the inefficiencies and inconveniences associated with the use of the plurality of conventional dental implements or instruments as described. 
         [0009]    What is needed is a solution to the problems presented by the use of a plurality of dental instruments in treating dental patients. Making the implements lighter in weight, or even smaller than current practice, while offering mitigation of some of the difficulties associated with conventional dental tools, presents only a small step forward in solving these problems. 
       SUMMARY OF THE INVENTION 
       [0010]    Accordingly, there is provided by the present invention a dental instrument or tool that solves the aforementioned problems. The result is increased efficiencies and comfort, for both dental personnel and patients. These benefits, which provide an advancement in the state of the art, arise from the basic concept: to reduce the plurality of separate dental implements or tools that must be present in the patient&#39;s mouth at one time by combining the functions formerly provided by a plurality of single-function tools into one tool that is designed to provide all of the necessary functions. The result is a multi-function dental tool or instrument that provides a mirror, a beam of light, streams of water (or other fluid) and air, or a suction device, and that is also light in weight and easily maneuverable. The multi-function dental tool described herein reduces the number of different, separate tools that must be present in the patient&#39;s mouth at one time and frees up the number of tools that must be held and manipulated by the dental personnel. Another way of stating the latter advantage is that fewer hands are required to manipulate the dental tools necessary for performing many routine dental treatment operations. 
         [0011]    In one embodiment, for use with a dental mirror tool having a body and a mirror attached to an end thereof and disposed at an angle to a longitudinal axis of the tool body, an apparatus, comprises a manifold disposed on the tool body proximate the mirror; a plurality of output ports disposed in an outlet side of the manifold, the ports positioned to emit streams of light and fluid and air toward a predetermined target; and a selection system disposed in the tool for selecting the light, fluid, or air emitted toward the predetermined target. 
         [0012]    In another embodiment, a method for use with a single dental tool provides streams of light, air, and fluid directed toward a target during a dental procedure, comprising the steps of: attaching a manifold having output orifices for air, fluids, and light to a body of the tool; connecting the orifices to sources of said air, fluid, and light; and controlling a substance emitted from the orifices to be directed toward the target. 
         [0013]    In yet another embodiment, a manifold for attaching to a handle of a dental tool having an angled mirror disposed on a first end thereof is provided, the manifold comprising a plurality of air, fluid, and light emission ports aimed at predetermined regions relative to the dental tool. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]      FIG. 1  illustrates a first perspective view of one embodiment of a multi-function dental tool according to the present invention; 
           [0015]      FIG. 2  illustrates a second, partially disassembled perspective view of the embodiment of  FIG. 1 ; 
           [0016]      FIG. 3  illustrates an exploded view of the removable head piece portion of the embodiment of  FIG. 2 ; 
           [0017]      FIG. 4  illustrates an exploded view of the main body portion of the embodiment shown in  FIG. 2 ; 
           [0018]      FIG. 5  illustrates an internal cross section view from a first side of the embodiment of  FIG. 1 ; 
           [0019]      FIG. 6A  illustrates a first side cross section view of the removable head piece portion of the embodiment of  FIG. 2  showing an air and water tube directed toward the mirror; 
           [0020]      FIG. 6B  illustrates a second side cross section view of the removable head piece portion of the embodiment of  FIG. 2  showing an air and water tube directed toward a patient&#39;s teeth; 
           [0021]      FIG. 6C  illustrates a third side cross section view of the removable head piece portion of the embodiment of  FIG. 2  showing a light path directed toward a patient&#39;s teeth; 
           [0022]      FIG. 7A  illustrates a side cross section view of the control body sub-assembly portion of the main body of  FIG. 5 ; 
           [0023]      FIG. 7B  illustrates a bottom view of the control body shown in  FIG. 7A ; 
           [0024]      FIG. 7C  illustrates an underside view of the control body chassis assembled with a retaining collar and wiring for the light assembly; and 
           [0025]      FIG. 8  illustrates an electrical circuit diagram of the light source portion of the embodiment of  FIGS. 4 and 5 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0026]    In the following description, reference numbers identifying the same structures are repeated in the successive drawings. The drawings illustrate one complete, preferred embodiment that utilizes the principles and concepts of the present invention set forth in the appended claims. 
         [0027]      FIG. 1  illustrates a first perspective or isometric view of one embodiment of a multi-function dental tool  10  according to the present invention. The dental tool  10  includes a main body  12 , a removable head piece  14 , a mirror  16 , and a supply line  18  having internal tubes connected to sources of fluid such as water, and air or vacuum. An air supply line may be connected to an air compressor (not shown) or a vacuum pump (not shown). The fluid supply line may typically be connected to a water supply such as a storage tank or mains system (not shown). The main body  12  of the dental tool  10  preferably includes an outer sleeve  20 . A main body cap  22  is disposed at a rearward end of the main body  12 , which encloses a connection interface and may also function as a strain relief for the supply line  18 . A retaining collar  24  is disposed at a forward end of the main body  12 , which secures the removable head piece  14  to the main body  12  as will be described. 
         [0028]    The removable head piece  14  includes a fluid/light manifold  26  attached to and integrated with the head piece  14 . The fluid/light manifold  26  provides a termination structure for the passages conducting fluid (e.g., water), air (either under pressure or a vacuum), and light to the outlet end of the dental tool  10  that provides the primary functionality of the tool. This manifold  26  includes the necessary orifices to provide outlets for fluids such as water and air, and a light beam output. For example, a first fluid/air orifice  28  may provide an outlet for a stream of air or water aimed toward a tooth of interest. A second fluid orifice  30  may provide an outlet for another stream of air or water aimed at the surface of the mirror for cleaning the mirror surface. It should be appreciated that, while water is contemplated for use in the dental tool  10  as described herein, fluids other than water may be used in certain treatment operations. A third light output orifice  32  may provide an outlet for a beam of light aimed at the surface of the mirror  16  to provide for illuminating a tooth or other structure of interest within a patient&#39;s mouth. The angles of the fluid, air and light outputs may be configured to suit particular applications for directing these materials or beams toward targets of interest. 
         [0029]    A mirror  16  may be supported by an angled mirror holder  50  of the removable head piece  14 . The mirror, as depicted in  FIG. 6A  is preferably supported at an angle Θ of approximately 30 degrees with the longitudinal axis C L  of the main body  12  of the dental tool  10 . This angle permits a dentist, hygienist, or assistant to enable viewing a patient&#39;s upper teeth without undue discomfort. However, other angles may be used, for example within a range of 10 to 60 degrees. In some embodiments of the dental tool  10  this angle may be adjustable. The angle O is shown in  FIG. 6A . 
         [0030]    A principle concept of the present invention—to provide multiple functions useful to a dentist or other dental care worker in a single implement—is made possible by the fluid/light manifold  26  component that is attached to or made integral with the body of a dental mirror tool proximate or nearby the mirror. This configuration enables embodiments that can direct streams of fluid (e.g., water) or air (either an air jet or an air suction or vacuum) or a light beam either toward the mirror or toward a target region in a patient&#39;s mouth in the vicinity of the mirror. Supplies of the fluid, air, and light may be provided for in the body of the multi-function dental tool and easily controlled using buttons accessible on the external surface of the tool that are placed to be readily operated with one hand. Fluids and air may be supplied to the tool from an external or portable source through a supply line or hose connected to the tool. It should be appreciated that the external source may be compact and portable to facilitate use of the dental tool in both civilian and military field situations because of the high utility of the multiple functions provided in the tool. In a preferred embodiment the tool requires no external connection to electricity because of its battery operation that energizes the light source within the tool. However, in alternate embodiments, a connection to an external source of electricity may be advantageously provided. 
         [0031]    Continuing with  FIG. 1 , a row of control buttons is disposed along an upper side of the main body  12 . Button  40  controls a light supply circuit (See  FIG. 8 ) to provide the light output from the light output orifice  32 . Buttons  42 ,  44 , and  46  are configured as a bar that tilts about a pivot axis directly below the center button  42 , to provide control of the flow of air and/or fluid, either individually or combined as will be described in  FIGS. 4 and 5 . A selector bar  48 , for selecting the direction of fluid or air to be emitted from the fluid/light manifold  26  toward the mirror  16  or toward the patient&#39;s teeth, is seen protruding from the side of the main body  12 . In operation, the selector bar  48  is pressed from one side of the main body  12  to the opposite side to direct the flow via one passage or the other, that is, toward the mirror or toward a tooth. An opening  140  in a center portion of the selector bar  48  acts as a valve for directing the flow of fluid—air and/or water, for example. See  FIGS. 4 and 5  for internal details of this structural feature. 
         [0032]    Materials preferred for use in fabricating most of the parts used in the dental tool  10  are generally either stainless steel, such as “alloy 304,” a readily available alloy of steel, chromium and nickel, or an FDA (U.S. Food and Drug Administration)-compliant plastic material, such as nylon. Generally, an engineering plastic suitable for high quality, precision manufactured small parts that can withstand repeated exposure to high temperatures (above 100 degrees Centigrade), which is FDA-compliant and meets the requirements for use in dentistry may be considered. In particular, the removable headpiece  14  must be able to withstand the heating of an autoclave used for sterilizing the dental tool  10  before each use, and be manufacturable with threads (See  FIG. 3 ) that are sufficiently durable and accurate to enable many cycles of removal from and secure re-attachment of the head piece  14  to the main body  12 . The material(s) selected may be fabricated by conventional methods for manufacturing precision parts, alone or used in combination, such as casting, machining or injection molding. These same materials are suitable for the rest of the solid or rigid parts. Materials referred to herein as “stainless steel” or “plastic” will be understood to mean the materials described in this paragraph unless otherwise noted. Further, as will be described, the dental tool  10  also contains several metal springs and a number of resilient sealing components fabricated from an FDA-compliant elastomer. The mirror  16  may be fabricated of glass with mirror finish or Rhodium-plated stainless steel. Persons skilled in the art will be familiar with suitable manufacturing methods for the embodiment described herein. 
         [0033]    The versatile multi-function dental tool illustrated in  FIG. 1  provides, in a single instrument a dental mirror, a light beam, an oral irrigation unit, an oral suction unit and may include, in an alternate embodiment through the use of an interchangeable head piece, an oral air jet unit for drying moist surfaces or clearing fluid or debris. The interchangeable head piece may also be used to enable the fluid or air to be directed alternately toward the mirror or toward a patient&#39;s teeth. Other combinations of the functional dental tools, simply by re-arranging the tubes in the head piece with ones of the appropriate configuration may be realized by persons skilled in the art. The remaining figures will illustrate and describe the various features and construction of the invention. 
         [0034]      FIG. 2  illustrates a second, partially disassembled perspective view of the embodiment of  FIG. 1  with the removable headpiece  14  removed from the main body  12  and exposing the bulkhead  38  within the proximate end of the headpiece  14 . The bulkhead  38 , to be described further in  FIGS. 3 and 4 , includes supporting passages  61 ,  63  for the air/fluid tubes  60 ,  62  (See  FIG. 3) and 65  for the light tube  64  to pass through from the control body  72  within the main body  12  to the head piece  14 . The passages  61  and  63  are supported and sealed in the bulkhead  38  by an elastomer seal  68 . An alignment pin  66  to be described is also shown in  FIG. 2 . The remaining structures shown in  FIG. 2  are as described in  FIG. 1 . The removable headpiece  14  is secured in the present example by the retaining collar  24 , which is itself retained by a lip formed into the end of the control body  70 , to be described as shown in  FIG. 5 . The head piece  14  is secured to the control body  70  by rotating the retaining collar  24  around the external threads  34  formed in the aft end of the removable headpiece  14 . Alignment of the head piece  14  and the control body  70  is keyed by an alignment pin  66  shown in  FIG. 3 , further described in  FIGS. 5 and 6A . As the headpiece  14  is drawn into contact with the control body  70 , the passages  61 ,  63 , and  65  will align with corresponding passages in the control body  70 . 
         [0035]      FIG. 3  illustrates an exploded view of the removable head piece  14  of the embodiment of  FIG. 2 . In addition to the structures previously described, which bear the same reference numbers, the drawing depicts several internal parts of the illustrative embodiment, including the tubes for conducting air or fluid and light between the bulkhead  38  and the fluid/light manifold  26 . A first fluid tube  60  includes an inlet end  170  that connects to the bulkhead  38  at an opening  61  and an outlet end  172  that connects to a first fluid (or air) outlet orifice  28  in the fluid/air/light manifold  26 . A second fluid tube  62  includes an inlet end  174  that connects to the bulkhead  38  at an opening  63  and an outlet end  176  that connects to a second fluid (or air) outlet orifice  30  in the fluid/light manifold  26 . A third light tube  64  includes an inlet end  178  that connects to the bulkhead  38  at an opening  65  and an outlet end  180  that connects to a third light outlet orifice  32  in the fluid/light manifold  26 . 
         [0036]    The bulkhead  38  and the first  60  and second  62  fluid tubes may be fabricated of stainless steel or FDA-compliant plastic as mentioned previously. The light tube assembly  64  may include a stainless steel sheath that contains a fiber optic strand or bundle of strands for conducting light emitted by a light assembly  100  to be described in  FIG. 4 . An alignment pin  66  may be used to facilitate alignment of each of the fluid and light tubes through the bulkhead  38  structure as the head piece  14  is connected to the control body  70 . The alignment pin  66  may be disposed in an upper portion of the bulkhead  38  in the illustrated example. 
         [0037]    The tubes  60 ,  62  and  64  includes output ends that are directed respectively to the mirror  16 , and to a region in a patient&#39;s mouth, i.e., away from the mirror. It should be understood that the output ends of these tubes may be oriented differently than illustrated in  FIG. 3 . It is possible that the removable head piece  14  may be configured with several different combinations of the output orientations of the tubes  60 ,  62 , and  64  to provide a set of head pieces to suit particular applications. The removable head piece  14  thus may function as an interchangeable part of the multi-function dental tool of the present invention. 
         [0038]    Continuing with the exploded view in  FIG. 3 , the mirror  16  is shown detached from the mirror holder  50  and the mirror holder  50  is shown as a separate structure that may be attached to a seat  51  formed in the nose end of the removable head piece  14 . The mirror  16  may be provided as, for example, a Rhodium-plated stainless steel component, or a more conventional glass with silvered backing. However, a disadvantage of the latter is the parallax error introduced by a mirror of clear material backed by a reflective surface. Other equivalent reflective surfaces that can withstand the stresses placed upon the materials and structure thereof may be used. The mirror  16  may be secured in the mirror holder by welding or bonding or press fit according to the particular materials used, as will be understood by persons skilled in the art. The mirror holder  50  may be assembled to the seat  51  by welding or using an epoxy adhesive or equivalent cement capable of withstanding the temperatures of an autoclave and the nominal mechanical stress of handling and manipulating the dental tool. In some applications, particularly those where interchangeable mirrors might be included, the mirror holder may be supported by a threaded engagement with the nose portion of the head piece  14 . The seat  51  may be configured to support the mirror holder  50  at the desired angle O depicted in  FIG. 5 . The angle Θ, to be described further with  FIG. 6A , is defined relative to the longitudinal axis C L  of the main body  12  of the dental tool  10 . This angle permits a dentist, hygienist, or assistant to enable viewing a patient&#39;s upper teeth without undue discomfort. However, other angles may be used, for example within a range of 10 to 60 degrees. In some embodiments of the dental tool  10  this angle may be adjustable. 
         [0039]      FIG. 4  illustrates an exploded view of the main body portion of the embodiment shown in  FIG. 2 . It will be observed that the orientation of the dental tool  10  in  FIG. 4  is opposite that shown in  FIGS. 1 ,  2 , and  3 . In other words, the head piece  14  end of the tool (and the forward end  52  of the main body  12  in  FIG. 1 ) is oriented to the left in the drawing in  FIGS. 1 ,  2 , and  3 , and to the right in  FIG. 4 . This orientation of the figures is chosen to best illustrate some of the detail features of the construction of the tool. Component parts in this drawing bearing the same reference numbers as described in  FIGS. 1 ,  2 , and  3  describe the same structural components. Further, this exploded view includes fasteners such as screws  90 , which are used in a number of places in assembling the parts as shown. The locations of these screw fasteners and the parts involved are clearly apparent in the drawing and will not be further described. In some applications, FDA-compliant epoxy adhesives may be used to assemble certain components together, as will be understood by persons skilled in the art. 
         [0040]    The assembly shown in  FIG. 4  includes the control body  70  and its chassis  72  that are enclosed within the main body cover  20 . After the main body cap  22  and the main body cover  20  are threaded onto the supply hose  18 , and the fluid and air lines in the supply hose  18  are attached to the barbed fluid fittings  116 ,  118  in the control body  70 , the main body cover  20  may be slipped over the control body  70  and secured by the main body cap  22 , which may be screwed into the bracket  74 . In a similar fashion, the internal passages within the control body  70  for the fluid and air  199 A and  199 B (See  FIG. 7B  to be described) may be connected through first and second junction tubes  66 A and  66 B inserted through passages  61  and  63  in the bulkhead  38 . The junction tubes  66 A and  66 B may be sealed by an FDA-compliant elastomer junction tube seal  68  as shown in  FIG. 4 . The bulkhead  38  is retained within the forward end  52  of the control body  70  using the stainless steel retaining ring  150 . The retaining collar  24  is screwed onto the (externally) threaded forward end  52  of the control body. Then, the removable head piece  14  is mated to the forward end of the main body  12  such that the fluid and light passages and tubes are aligned with the ports in the bulkhead  38  assembly, the retaining collar  24 , previously installed on the forward end  52  of the control body  70  may be screwed to the threaded portion of the removable head piece. 
         [0041]    The control body  70  contains the fluid/air poppet valve assemblies  92  through  108 , the control buttons  40  through  46  and their related parts, and the light assembly  100  to be described. The control body  70  and the bracket  74  are secured to the chassis  72  using the screws  90  as shown. The chassis  72  also supports a circuit board assembly  120  that includes an electric circuit  200  (See  FIG. 8 ) and a battery  130  (shown as battery  220  in  FIG. 8 ) for powering the electric circuit  200  and the light assembly  100 . The circuit board  120  is secured to the chassis  72  using the screws  90  as shown. The control body  70 , chassis  72 , and bracket  74  may be fabricated from the same stainless steel and FDA-compliant plastic materials described herein above. 
         [0042]    The circuit board  120  includes a battery  130  mounted thereon in first and second clips  122 ,  132 , which may be attached to the circuit board  120  with rivets  124 ,  134 . The battery  130  may be any small battery capable of supplying at least 3.3 Volts to operate an LED as the light source for the dental tool  10 . In the illustrated embodiment, which includes a regulated power supply, a Lithium-ion, rechargeable type CR123 battery rated at 3.6 Volts may be provided. The circuit board  120  may be a printed circuit board (PCB) having circuit trace contacts  228 ,  230  (not shown in  FIG. 4 , but see  FIG. 8  for the circuit diagram) disposed parallel with and spaced closely to each other on the upward side of the circuit board  120  on the upper surface of the tab  136 . The circuit board  120  is mounted on the upper surface  72 A of the chassis  72  such that the light button actuator  86  is positioned immediately above the pair of closely spaced circuit board traces  228 ,  230 . These contacts  228 ,  230  of the switch  40  shown in  FIG. 8  are connected together whenever the light button actuator  86  is pressed downward into contact with the contacts  228 ,  230  against the tension of the return spring  82  that is seated in a recess  81  in the control body  70 . The light button actuator  86  slides within a sleeve  84  disposed in the control body  70  just below the light button  40  and return spring  82 . The contact closure thus provided whenever the switch button  40  is pressed connects a signal to the circuit to be described that energizes a light assembly  100 . 
         [0043]    The light assembly  100  is also depicted in  FIG. 4 . When assembled, it is supported within a recess in the control body  70  with a forward end butted up against the bulkhead  38 . The light assembly  100  includes a small diameter tube serving as a light assembly body  186  containing a double convex lens  182  in the forward end that is butted up against the bulkhead  38  and a light emitting diode (LED)  184  disposed in the light assembly body  186  just behind the lens  182  such that the terminals of the LED  184  extend toward the PC board  120 . The LED  184 , preferably in this example a round, 5 mm diameter LED lamp providing a white light, is connected to the circuit board  120  through a wiring harness  212  (See  FIG. 7C ) routed from the terminals of a header  188  on the circuit board  120  to the first and second terminals of the LED  184 . The pair of wires in the wiring harness  212 , which may preferably be approximately 24 gauge stranded, insulated wire, may be dressed along and against the underside of the chassis  72  between the circuit board  120  and the light assembly  100 , where the wires of the wiring harness  212  may be soldered to the terminals of the LED  184 . Details of the wiring harness  212  shown in  FIG. 7C  to be described herein below. The circuit for driving the LED  184  is shown in  FIG. 8 . 
         [0044]    The light switch assembly is controlled by the light switch button  40  and the contacts  228 ,  230  on the circuit board  120 , which thus form a momentary switch to control the light beam of the dental tool  10 . Each operation of the switch button  40  applies a ground signal to pin  2  of a PIC microcontroller U 1  (See microcontroller  232  in the circuit  200  shown in  FIG. 8 ) on the circuit board  120  to turn on a MOSFET  236  to draw current through the LED  184  in the light assembly  100  until a subsequent operation of the light switch button  40 . The subsequent operation of the light switch button  40  signals the MOSFET  236  to turn OFF, opening the LED  184  circuit to extinguish the light source. In other applications, the light switch assembly may be a latching type such as, for example, a mechanical push ON, push OFF type so that the light may remain energized during use without having to hold the light switch button  40  in a depressed position. However, the PIC microcontroller  232  and MOSFET  236  combination was chosen for this application because of the mechanical simplicity and tight space requirements of the dental tool  10 . 
         [0045]    Continuing with  FIG. 4 , the poppet valves  92 - 98  and  102 - 108  contained within the control body  70  for controlling the flow of fluids will be described. The control body  70  may be a solid machined, cast, or molded structure of material such as alloy  304  stainless steel or nylon having bodies  92 ,  102  for receiving the valve poppets  96 ,  106  therein. The valve poppets  96 ,  106  are disposed within the respective valve bodies  92 ,  102 . The valve seals  94 ,  104  of an FDA-compliant elastomer are also seated against valve seats  93 ,  103  formed respectively in the chassis  72  when the control body  70  and the chassis  72  are assembled together. The side view of the control body assembly shown in  FIGS. 7A and 7B  illustrate the assembled relationship of these poppet valve  92 - 98  and  102 - 108  assemblies. 
         [0046]    Actuation of the poppet valves  92 - 98  and  102 - 108  for controlling the flow of fluids through the dental tool  10  is provided by the button assembly  76 . The button assembly  76  is seated into an elongated relief  77  formed into the upper side of the control body  70 . A loop  43  formed into the underside of the button assembly  76  is secured with a pin  78  that is inserted into a bore  79  passing through the control body  70  as shown. In operation, the button assembly  76  rocks about the pin  78  so that either end,  44  or  46  of the button assembly  76 , when pressed, operates its respective poppet valve  92 - 98  or  102 - 108  to release a flow of fluid—typically air or water—into the removable head piece  14 . If the user presses the center button  42 , both poppet valves  92 - 98  and  102 - 108  may be operated to release fluids into both the first and second fluid tubes  60 ,  62  in the removable head piece  12 . Thus, the button assembly  76  functions as a three-way control in the manner of A, B, or A and B. 
         [0047]    The selector bar  48 , for selecting the direction of fluid or air to be emitted from the fluid/light manifold  26  toward the mirror  16  or toward the patient&#39;s teeth, is installed laterally within a selector passage  141  through the side of the main body  12 . The selector bar  48  is sealed in the selector passage  141  by the four elastomer O-rings  142 , and secured there within by a screw  141  as shown in the exploded view of  FIG. 4 . In operation, the selector bar  48  is pressed from one side of the main body  12  to the opposite side to direct the flow one direction or the other. An opening  140  in a center portion of the selector bar  48  acts as a valve for directing the flow of fluid—air and/or water, for example. IN one position the opening  140  is aligned with a passage that permits the flow of fluid or air to be directed toward the mirror; in the other (second) position, the opening  140  is aligned with a passage that permits the flow of fluid or air to be directed to the patient&#39;s teeth. 
         [0048]      FIG. 5  illustrates an internal cross section view from a first side of the embodiment of  FIG. 1 , showing the assembled relationship of many of the component parts illustrated in the exploded view of  FIG. 4 . It should be noted that the control body  70  and its chassis  72 , as assembled, include the bulkhead assembly  38 , the selector bar  48 , the first and second poppet valve assemblies  92 - 98  and  102 - 108 , the light assembly  100  and its light switch button  40  and actuator  86  assembly, and the circuit board  120  and battery  130 . As enclosed in the main body cover  20 , this assembly makes up the main body  12  of the dental tool  10 . The main body cover  20  is secured to the control body by the main body cap  22  when it is screwed into the bracket  74  that is attached to the control body chassis  72  as described in  FIG. 4 . The fluid supply line  18  containing the fluid and air lines  160 ,  162  is connected to the barbed fluid fittings  116 ,  118  respectively. The barbed fluid fittings  116 ,  118  are screwed into the control body  70  at the location shown in  FIG. 5  behind the light switch actuator  86 . Finally, after the removable head piece  14  is mated to the forward end of the main body  12  such that the fluid and light passages and tubes are aligned with the ports in the bulkhead  38  assembly, the retaining collar  24 , previously installed on the forward end  52  of the control body  70  may be screwed to the threaded portion of the removable head piece. The alignment of the passages is facilitated by the alignment pin  66  shown in the figure as the retaining collar  24  is drawn into a secured position. This completes the assembly of the major subassemblies of the dental tool  10 . 
         [0049]    Continuing with  FIG. 5 , a portion of a longitudinal axis C L  runs lengthwise through the body of the dental tool  10  is shown in  FIG. 6A  as a straight line. It will be understood that the longitudinal axis C L  extends through the entire dental tool  10 . However, persons skilled in the art may recognize that this axis may be curved or bent at a defined angle to provide a dental tool that is balanced a certain way or formed for ease of manipulation. Such considerations may arise from the use of certain materials that are lighter than others used in the tool or, when used near one end of the tool may have a substantial affect on the center of gravity. Providing a dental tool  10  that is curved or bent at an angle along its length is among the alternative configurations contemplated in this invention. For example, in some embodiments it may be reasonable to provide a dental tool configured with the multiple functions described herein that is formed with a handle aligned away from the longitudinal axis CL instead of aligned with it. Alternatively, other embodiments, which may be intended to be supported other than by hand, may be configured to be supported by or suspended from other apparatus, thus requiring alternative forms and/or features in the tool without departing from the concepts described herein. 
         [0050]      FIGS. 6A ,  6 B, and  6 C depict the removable head piece  14  shown in  FIG. 3  but as assembled in cross section. All of the structures identified in the  FIGS. 6A ,  6 B, and  6 C are the same ones described in  FIG. 3  and bear the same reference numbers.  FIG. 6A  illustrates a first side cross section view of the removable head piece  14  of the embodiment of  FIG. 2  showing an air and water tube  60  installed within the body of the removable head piece  14  and directed toward the mirror  16 . The air and water tube  60  includes an inlet end  170  supported by the bulkhead  38  and sealed by an elastomer seal  68 , and an outlet end with orifice  172  supported in the fluid/light manifold  26 . Also shown in this view is an alignment pin  66  to ensure correct alignment between the removable head piece  14  and the control body  70  in the main body  12  when they are assembled together. Further, the light passage  64  to be described in  FIG. 6C  is also shown in profile. 
         [0051]    Continuing with  FIG. 6A , the longitudinal axis C L  that runs lengthwise through the body of the dental tool  10  defines a reference line for other aspects of the invention. For example, the angle Θ of the mirror  50  (and the mirror  16 ) relative to the longitudinal axis C L  of the main body  12  is shown in this illustrative example as approximately 30 degrees. This angle, in other embodiments, may be set within the range of 10 to 60 degrees. Further, in some embodiments the angle Θ may be made adjustable. 
         [0052]      FIG. 6B  illustrates a second side cross section view of the removable head piece  14  of the embodiment of  FIG. 2  showing an air and water tube  62  installed within the body of the removable head piece  14  and directed toward a patient&#39;s teeth. The air and water tube  62  includes an inlet end  174  supported by the bulkhead  38  and sealed by the elastomer seal  68 , and an outlet end with orifice  176  supported in the fluid/light manifold  26 . 
         [0053]      FIG. 6C  illustrates a third side cross section view of the removable head piece portion of the embodiment of  FIG. 2  showing a light passage  64  installed within the body of the removable head piece  14  and directed at an outlet end toward a patient&#39;s teeth. The light passage  64  includes a fiber optic bundle installed within a tube or sheath, an inlet end  178  supported by the bulkhead  38  and an outlet end with orifice  180  supported in the fluid/light manifold  26 . The fiber optic bundle is preferably polished on both ends and sealed with an FDA-compliant epoxy. The alignment pin  66 , provided to ensure that the passages for water, air, and light are correctly aligned when the removable head piece  14  is installed to the control body  70  is clearly shown in  FIG. 6C . 
         [0054]      FIG. 7A  illustrates a side cross section view of the control body sub-assembly  180  portion of the main body  12  of  FIG. 5 , detached from the chassis  72  and other structures supported by the chassis  72  for clarity.  FIG. 7B  illustrates a bottom view of the control body sub assembly  180  shown in  FIG. 7A . Structures identified in  FIGS. 7A and 7B  having the same reference numbers that appear in previous figures—primarily FIGS.  4  and  5 —refer to the same structures. The view in  FIG. 7A  of the control body  70  illustrates the light assembly  100 , the poppet valve assemblies  92 - 98  and  102 - 108  and the fluid control button  76 , the selector bar  48  and the light switch assembly  82 - 86  and the light button  40 . 
         [0055]    The light assembly  100  shown in  FIG. 7A  includes a double convex lens  182 , a light emitting diode  184 , and a light assembly housing  186 . The double convex lens  182  may be preferably be formed of glass or FDA-compliant plastic materials. The light emitting diode (“LED”)  184  used in the illustrative example may be a 5 mm round unit designed to emit a cool white light having a minimum color temperature of 4600° K (degrees Kelvin) and a minimum luminous intensity of approximately 20,000 mcd (millicandles) at a nominal forward current of approximately 30 mA (milliAmperes) when operated at its rated forward voltage. Persons skilled in the art will recognize that the particular choice of LED depends closely on the application and may vary depending on additional design considerations. The light assembly housing may be molded or machined of FDA-compliant plastic or alloy 304 stainless steel. The internal dimensions of the housing  186  may be calculated to allow a nominal press fit of the lens  182  and LED  184 . 
         [0056]    The poppet valve assemblies shown in  FIGS. 7A and 7B  control the flow of fluid and or air according to how the button  76  is pressed, as described previously in  FIG. 4 . When released, the button  76  blocks the flow of fluid (e.g., water) and or air; when one end (either  44  or  46  of the button  76  is pressed the fluid or air in the associated passage  194  or  196  machined in the control body  70  is allowed to flow through the respective poppet valve to a common passage  198 , and thence through bypass passages  199 A or  199 B and the bulkhead  38  to a corresponding tube  60 ,  62  in the removable head piece  14 . The passages  194 ,  196 ,  198 ,  199 A and  199 B may be preferably machined in the control body (such as by routing and drilling, for example) similar to the valve body used in a typical automatic transmission for automobiles. When the button  76  is pressed at its midpoint  42  (or, alternatively, at both ends  44 ,  46  simultaneously) fluid and or air will both be admitted to the common passage  198  for dispersal through the passages  198  and  199  and fluid tubes  60 ,  62 . The button  76 , retained in the control body  70  by a pivot pin  78  positioned in a slot  43  in the button  76 , is urged into its released position by first  98  and second  108  poppet springs as shown in  FIG. 4 . 
         [0057]    Continuing with  FIG. 7A and 7B , the selector bar  48 , which slides laterally in a bore  79  passing through the control body  70 , provides control to cause the fluid or air selected by one of the poppet valve assemblies  92 - 98  or  102 - 108  to be directed to one or the other of the two fluid tubes  60 ,  62 , depending whether the user wishes to direct the fluid or air toward the mirror  16  or to the patient&#39;s teeth. The selector bar  48  is retained within its bore  79  by a retaining screw  141 . The light switch assembly  80  includes the light button  40 , return spring  82 , sleeve  84 , and switch actuator  86  contained within a bore  81  in the control body  70 . Also depicted in  FIGS. 7A and 7B  are the first and second barbed fluid fittings  116 ,  118  that are screwed into threaded bores in the control body  70 . The barbed fluid fittings  116  and  118  provide connection points for the fluid and air lines  160  and  162  within the supply line  18  shown in  FIG. 5 . 
         [0058]      FIG. 7C  illustrates an underside view of the control body chassis  72  assembled with a retaining collar  24  and wiring harness  212  for the light assembly  100 . The chassis  72  is secured to the control body  70  with screws  90 , several of which are not illustrated for clarity of the wiring harness  212  that is dressed along the surface of the chassis  72  as shown. The chassis  72  is depicted between the retaining collar  24  and the bracket  74 . The circuit board  120  is also visible in this view through the elongated opening  203  in the chassis  72 . The wiring harness  212  connects between first and second terminal pins  202 ,  204  that are positioned in the opening  203  and connect to the circuit board  120 . The connection between the individual wires of the harness  212  and the terminal pins  202 ,  204  is via a receptacle  206 . The opposite ends of the wires in the harness  212  may be soldered to the first  208  and second  210  pins of the LED  184  or connected using a receptacle (not shown) suitable for the purpose as readily understood by persons skilled in the art. The LED  184  is disposed within the light assembly  100  and thus not visible in this view, except for the first and second pins  208 ,  210 . Please refer to  FIGS. 5 and 7A  for the detail of the light assembly. The first and second wires of the harness  212  may preferably be twisted to assist in maintaining a neat dress against the surface of the chassis  72 . 
         [0059]      FIG. 8  illustrates an electrical circuit diagram  200  of the light source portion of the embodiment of  FIGS. 4 and 5 . A voltage regulator  224  powered by a battery  220  having an output  222  applied to an input terminal of the voltage regulator is provided to produce a stable voltage at an output terminal  226 . The battery voltage may be rated at 3 to 9 Volts, depending on the input voltage requirements of the voltage regulator  224  and the type available that meets the small physical size and current requirements. In the present embodiment a 3.6 Volt Lithium ion rechargeable battery may be used. The voltage at the output terminal  226  “3.3 Vcc” may preferably be 3.3 Volts in the illustrated example, which is sufficient to power the LED  184  light source and the PIC microcontroller  232  programmed to control the current supplied to the LED  184  light source and to provide a debounce function to ensure reliable operation of the light switch  40 . Light switch  40  includes first and second terminals, which may be first  228  and second  230  PC board traces disposed in an extension tab portion  136  of the circuit board  120  as shown in  FIG. 4 . The PC board traces  228  and  230  are not shown in  FIG. 4  but are represented by the terminal symbols  228 ,  230  in  FIG. 8 . The light switch  40  is connected to a GP5 terminal of the PIC microcontroller  232 , and to a pull up resistor  248  such that the GP5 pin of the microcontroller  232  is pulled HIGH (toward the 3.3 Volt supply) except when the switch  40  is activated by pressing on the light switch button  40  to pull the GP5 terminal LOW to energize the light source. This action causes the gate drive signal to be output from terminal GPO of the microcontroller  232  on signal line  238  to the gate of the MOSFET switch  236 , causing it to conduct current through the LED  184 , which is connected to the regulated supply voltage through a resistor  240 . In the illustrated embodiment, one suitable LED is a type C503D-WAN available from Cree, Inc, Durham, N.C. 27703. 
         [0060]    Continuing with  FIG. 8 , the 3.3 Volt regulated supply is shown connected to a V DD  terminal pin of the microcontroller  232 . Further, a second pullup resistor  246  is shown connected to an MCLR* terminal of the microcontroller  232 . A voltage divider formed by two equal valued resistors  242 ,  244  provides a voltage of one half the regulated supply voltage to a GP4/AN3 terminal of the microcontroller. The microcontroller  232  is programmed to cause the LED  184  to blink, indicating low battery voltage, if this value equal to one-half the supply voltage falls below an internal reference level. In the illustrated embodiment one suitable microcontroller may be a type PIC12C671. 
         [0061]    Persons skilled in the art will understand that numerous variations are possible or that additional features may be included in the illustrated circuit to adapt it to particular applications. The present circuit is illustrated to provide one generalized method of replicating the present invention. In the illustrated embodiment a separate ON-OFF switch to control application of power to the circuit from the battery is not included because the circuit draws negligible current when the dental tool  10  is not in use, and the circuit is thus always in a stand-by, ready to use condition as long as the battery provides sufficient voltage. A quick tap on the button  40  to test the light can be used to confirm the readiness of the dental tool  10  for use. This particular approach eliminates a separate on-off switch, which is both a cost and an ergonomic issue in the use of the tool. 
         [0062]    While the invention has been shown in only one of its forms, it is not thus limited but is susceptible to various changes and modifications without departing from the spirit thereof.