Abstract:
Method and apparatus for visually grouping and organizing endodontic files for expeditious selection and use during a root canal procedure. The method calls for marking reference points for each root canal on the crown of the tooth to be treated, using distinguishing colors or other visually perceptible characteristics. The reference points so color coded correspond to colors marked on a file holder, so that a dental practitioner can quickly and accurately select a file from an array of prepared files, wherein the selected file is appropriate for a tooth being addressed at any one point during the procedure. Files associated with any one root canal are held in a portion of the file holder bearing a distinctive color, and thus can be readily identified as being associated with one another. Marking the tooth with a similar color enables the several files prepared for any one root canal to be quickly associated with the correct root canal. The preferred file holder is a jig or gauge configured to provide an additional function of setting exposed file lengths for each file to be used in each canal. The gauge has a plurality of stepped members slidably mounted thereon in a position enabling the steps to engage files held in the holder. Rubber stops placed on the files can be appropriately positioned along their respective files for a root canal procedure.

Description:
REFERENCE TO RELATED APPLICATION  
       [0001]    This application claims priority benefit of Provisional Patent Application Serial No. 60/180,961, filed Feb. 8, 2000 and of Utility Patent Application Serial No. 09/778,815, filed Feb. 8, 2001. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention relates to geometric dental tools and more particularly to apparatus and method of visually correlating prepared dental instruments with associated root canals being treated in a root canal procedure, e.g., by color coding of a holder of the tools coordinated with marks made on the operative tooth for each distinct canal of that tooth.  
           [0004]    2. Description of the Prior Art  
           [0005]    When the nerve of a tooth dies or other injury occurs to pulp tissue of a tooth, potentially necrotic and infected tissue must be removed. The canal containing pulp tissue is enlarged and sterilized, and then filled with an inert material. Removal of pulp tissue and enlargement of the canal are performed by drilling a hole through the top of the tooth, then reaming out the canal of each root of the tooth. Reaming of each canal is performed usually in several progressive steps, starting with the smallest file diameter and progressing to the largest. Each of the files must be set to the radiographic length of that canal. For example, a single root canal procedure may require four or more files of varying diameter for each canal of the tooth presented. The progression culminates in a single file of minimum diameter utilized at the apex of the root.  
           [0006]    The procedure requires establishment of a fixed point of reference, called the datum point, on the tooth itself. Each canal to be treated requires a datum point that is within the diameter of the stop which encircles each file. The distance from the datum point to the tip end, or apex of the root, is established. This is referred to as the “radiographic length”, usually obtained from X-rays. From this information, the dimensions of progressive file lengths are determined according to the particular surgical technique chosen by the clinical practitioner. Because of the number of files of differing diameter and lengths required, it is not uncommon for a treatment of a single, multi-canal tooth to include more than sixty file length settings.  
           [0007]    The several sets of endodontic files for each succeeding increment of file length are prepared with great precision to correspond to the length of each section of each root canal. Generally torroidal or disc-like resilient stops are placed over each endodontic file which will be utilized in the procedure. These stops limit maximal penetration of the file into the canal. Precision of placement of a stop on its associated file is of great importance in limiting the exposed portion of the files. The precision required and the large number of settings present a significant risk of error, and multiply time required to perform the procedure.  
           [0008]    Contemporary practice in root canal procedures is to record pertinent data relating to the procedure on a form which becomes part of the permanent record. However, due to anatomical variations and other conditions of the procedure, sequence in which instruments are used may vary from the sequence in which instruments are listed on the form. This causes the practitioner to devote unnecessary time and attention to assure that appropriate file lengths be selected for each root canal. This is distracting, potentially introduces error to the procedure, and increases the amount of time required to perform a root canal procedure. The prior art has not suggested a method of and apparatus for visually relating the radiographic length of a canal and its associated datum point on the tooth to the endodontic gauge.  
         SUMMARY OF THE INVENTION  
         [0009]    The present invention improves on conventional apparatus and procedures used for root canal procedures. Notably, both the datum points placed on the teeth and the apparatus used to hold prepared endodontic files are color coded to expedite selection and use of the endodontic files during the procedure. This is accomplished by correlating the color of the apparatus containing files for a given tooth canal to the color of the datum points for that canal marked on the operative tooth.  
           [0010]    The apparatus for holding prepared endodontic files can be any device provided with slots or other structure for receiving or holding files, the device preferably having structure for segregating groups of files by association with one root canal. It is preferred to employ an endodontic gauge of a type more particularly set forth in the above referenced prior application, which is hereby incorporated by reference. If improved according to the principals of the present invention, the endodontic gauge presented therein provides a single apparatus which enables both setting of exposed length of entire sets of files, and also color coded identification which enables expeditious selection of files and reduces risk of using a file set up for one canal on a different canal.  
           [0011]    The apparatus is provided with predetermined coloring or other visual characteristics to enable the user to sense organization of files grouped by association with a particular root canal. Reference marks or datum points of identical or substantially similar coloring are placed on each tooth for each group of files associated with one root canal. When it is time to ream a root canal, selection of appropriate files is assured by selecting a file from that portion of the apparatus holding prepared files which bears the same coloring as the datum point placed on the tooth for the corresponding canal. Time and concentration expended on assuring selection of proper files and their use in the proper associated canal are minimized. Chances of introducing error to the procedure and possibly damaging a root are correspondingly reduced.  
           [0012]    Accordingly, it is an object of the invention to organize visually sets of endodontic tools with respect to their associated canals of the operative tooth.  
           [0013]    It is a further object of the invention to utilize color coding to visually group sets of files and to associate said files with the appropriate canal for which they are set up.  
           [0014]    It is an object of the invention to provide improved elements and arrangements thereof in an apparatus for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes.  
           [0015]    These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]    Various other objects, features, and attendant advantages of the present invention will become more fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein:  
         [0017]    [0017]FIG. 1 is a perspective view of an embodiment of the apparatus of the present invention, which view omits elements of color coding of the present invention.  
         [0018]    [0018]FIG. 2 is an environmental, top plan view of the device of FIG. 1, again omitting elements of color coding.  
         [0019]    [0019]FIG. 3 is a diagrammatic plan view of slides generally corresponding to four such slides seen along the center of FIG. 1, again omitting elements of color coding.  
         [0020]    [0020]FIG. 4 is an enlarged end cross sectional detail view taken along line  4 - 4  of FIG. 2.  
         [0021]    [0021]FIG. 5 an enlarged top plan detail view of one of the slides depicted along the center of FIG. 1, again omitting elements of color coding.  
         [0022]    [0022]FIG. 6 is an enlarged environmental side elevational detail view of the slide of FIG. 5, showing an endodontic ruler in place for making measurements.  
         [0023]    [0023]FIG. 7 is a diagrammatic, perspective view of a tooth bearing colored reference marks or datum points made according to the invention.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0024]    [0024]FIG. 1 of the drawings shows a preferred form of a device for setting and holding files. This device is a gauge  10  which provides an additional function of selectively positioning stops along the shaft of an endodontic file (see FIG. 2). It should be understood from the outset that the precise nature of any particular file holding device employed is not critical per se to the invention, apart from its ability to set the lengths, hold, and present files to view. The invention presented herein resides in color coding to enable visual organization of endodontic files for expeditious selection during a root canal procedure. Gauge  10  is presented only as a preferred embodiment of a file holder, and will be described to a level of detail affording the reader appreciation of its additional function in setting effective file lengths.  
       1. Description of the Preferred File Holder  
       [0025]    Gauge  10  comprises a base  12  in which are formed four coplanar, parallel tracks  14 ,  16 ,  18 ,  20 . A plurality of slidable members or slides  22 ,  24 ,  26 ,  28  which are dimensioned and configured to be slidably disposed within tracks  14 ,  16 ,  18 , and  20  are shown installed. Base  12  has a file retainer in the form of retaining barrier  30  spanning tracks  14 ,  16 ,  18 ,  20 . Base  12  has an upper surface  32  common to retaining barrier  30  and to side walls  34  of tracks  14 ,  16 ,  18 ,  20 . The function of barrier  30  will be described hereinafter.  
         [0026]    The bottom of base  12 , as depicted in FIG. 1, is formed by a floor  38  (see also FIG. 2) which extends continuously from side  40  to respective opposing side  42 , and from proximal side  44  to respective opposing distal side  46 . Designation of side  44  as proximal and of side  46  as distal are merely for semantic convenience. The proximal side is that into which files are inserted into retaining barrier  30 . The term will also be applied for convenience to tracks  14 ,  16 ,  18 ,  20 , and refers to that end of tracks  14 ,  16 ,  18 ,  20  proximate retaining barrier  30 .  
         [0027]    Apart from being a structural member, floor  38  closes each track  14 ,  16 ,  18 , or  20  at the bottom thereof. This both assists in guiding and constraining slides  22 ,  24 ,  26 ,  28  to move only longitudinally within associated tracks  14 ,  16 ,  18 ,  20  which are dimensioned and configured to accomplish this, and also obstructs contaminants (not shown) from impinging from below upon endodontic files (see FIG. 2) held within base  12 .  
         [0028]    The use of gauge  10  is illustrated in FIG. 2. An endodontic file  2  is shown held in base  12 . File  2  is passed through one of five openings  48 ,  49 ,  50 ,  51 ,  52  formed in retaining barrier  30  at track  14 . Openings  48 ,  49 ,  50 ,  51 ,  52  are preferably slots which are open from above so that a file may be laid in each one prior to sliding the file into contact with its associated slide. Openings  48 ,  49 ,  50 ,  51 ,  52  are each dimensioned and configured to receive therein one endodontic file such that all endodontic files (only one file  2  is shown) inserted within openings  48 ,  49 ,  50 ,  51 ,  52  are in coplanar relation to one another. A rubbery, generally torroidal or disc-like stop  4  has been placed in encircling relation to the shaft of file  2  prior to insertion of file  2  into opening  50 . File  2  has been passed through opening  50  until its distal end contacts a step  54  formed on slide  22 .  
         [0029]    Slide  22  has a stepped surface facing retaining barrier  30  at its proximal end (that being the end facing retaining barrier  30 ) and an opposed distal end. The stepped surface is disposed to occupy track  14 , and to move selectively towards and away from the proximal end of track  14  when slide  22  traverses track  14 . The stepped surface has five flat steps  54 ,  55 ,  57 ,  58 ,  60  (see FIG. 5). Each step  54 ,  55 ,  57 ,  58 , or  60  is spaced apart from the distal end of track  14  by a distance interval different from that by which every other step  54 ,  55 ,  57 ,  58 , or  60  is spaced apart from the distal end of track  14 .  
         [0030]    In the depiction of FIG. 2, slide  22  has been moved to a selected position within track  14  such that exposed length  6  of file  2  corresponds to a measurement derived from the radiographic length, which is established by X-ray or equivalent images (not shown). Positioning of slide  22  is precisely accomplished by moving slide  22  to appropriate registry with measurement indicia  56  disposed upon upper surface  32  of base  12  proximate and along track  14 . Indicia  56  enables visual confirmation of exposed length of each endodontic file retained within retaining barrier  30 . A similar goal is achieved by the use of an endodontic ruler, as explained hereinafter. Slide  22  bears a suitable index or reference mark (not shown) for registry with indicia  56 . Stop  4  is prevented from moving in tandem with file  2  as file  2  is pushed through opening  50 , stop  4  thereby moving to an adjusted position along the shaft of file  2  as facilitated by retaining barrier  30 . Alternatively stated, retaining barrier  30  causes stop  4  which has been placed in encircling relation on the shaft of endodontic file  2  to slide along the shaft when the shaft is advanced through opening  50 . When exposed length  6  of file  2  touches step  54 , position of stop  4  on file  2  has been adjusted to the desired distance. File  2  is now ready for use.  
         [0031]    Other files (not shown), also for use on the same root canal, will be similarly adjusted, using other openings  48 ,  49 ,  51 , or  52 , of retaining barrier  30 , and other steps  55 ,  57 ,  58 , or  60  of slide  22 . Another file (not shown) is passed through an opening  48 ,  49 ,  51 , or  52  until it contacts its associated step  55 ,  57 ,  58 , or  60  of slide  22 . The length of the exposed portion of file  2  and other files adjusted using slide  22  is predetermined once slide  22  has been adjusted to the appropriate position in accordance with the radiographic length of the canal. The procedure for positioning the stops of the subsequent files is the same as that employed for file  2 . Files associated with any one slide may obviously be adjusted in any desired order.  
         [0032]    Each track  14 ,  16 ,  18 , or  20  preferably has height, width of magnitude greater than that of the height, and length of magnitude greater than that of the width. This relationship causes gauge  10  to be generally planar, apart from nominal and structural thickness of its components, so that all of the files are held in an accessible, visible parallel, coplanar array.  
         [0033]    It will be appreciated that because track  14  and slide  22  are generally similar in function to respective tracks  16 ,  18 , and  20  and slides  24 ,  26 , and  28 , description of track  14  and slide  22  will therefore be understood to apply as well to tracks  16 ,  18 , and  20  and to slides  24 ,  26 , and  28 . The only significant difference is in dimensions and proportions among the various slides, as will be further explained hereinafter. In a similar vein, retaining barrier  30  has five openings (not indicated by individual reference numerals) for each one of tracks  16 ,  18 ,  20 , as well as for track  14 .  
         [0034]    In operation, each track  14 ,  16 ,  18 , or  20  is assigned to a canal in the tooth to be treated. Each track  14 ,  16 ,  18 , or  20  can, with a single adjustment to its associated slide  22 ,  24 ,  26 , or  28 , therefore set up to five operational file lengths as dictated by the chosen endodontic technique. Each operational length is a predetermined variance from the radiographic length of the individual canal.  
         [0035]    All tracks  14 ,  16 ,  18 ,  20  face upwardly when base  12  is oriented horizontally, with floor  38  facing downwardly. Therefore, all five file lengths established by slides  22 ,  24 ,  26 ,  28  after adjustment are exposed to view from above.  
         [0036]    Once positioned as desired, and prior to inserting files into openings  48 ,  49 ,  50 ,  51 ,  52 , slide  22  is secured within base  12  by turning a setscrew which preferably is a thumbscrew  62 . It will be understood that slides  24 ,  26 ,  28  each have an equivalent thumbscrew.  
         [0037]    Differences among the dimensions and proportions of the various slides will now be described, with reference to FIG. 3. FIG. 3 illustrates a second embodiment of a gauge wherein slides  23 ,  25 ,  27 ,  29  each have other than five steps. The number of steps arbitrarily selected for purpose of illustration is three. Variations among the slides are selected to conform to teachings of different clinical techniques for root canal procedures. FIG. 3 is diagrammatic in that it shows only the profile or silhouette of each slide, omitting other features described elsewhere herein. It will be understood that the various slides of FIG. 3 include necessary features required for operability but which are deleted from FIG. 3.  
         [0038]    It will be seen that distance intervals  64 ,  66  by which steps of slides  23 ,  25 ,  27 ,  29  of a first group of slides are spaced apart from one another are constant or similar distance intervals. This is not the only possible relationship. A second group comprising slides  68 ,  70 ,  72 ,  74  has a distance interval  78  separating a step  80  for establishing the shortest exposed file length from an intermediate step  82  which is smaller than a distance interval  84  separating intermediate step  82  from step  86 . It will be understood that although steps  80 ,  82 ,  86  are shown only on slide  68 , slide  68  and steps  80 ,  82 ,  86  are representative of slides  70 ,  72 ,  74 .  
         [0039]    [0039]FIG. 4 illustrates one method of securement of slide  22  within track  14 . Thumbscrew  62  is seen to comprise an enlarged head  108  which enables grasping by finger and a threaded shank  110  which threaded shank  110  engages a threaded hole  112  formed in slide  22 . Shank  110  passes through a slot  96  (see FIG. 5) formed in slide  22 . Thumbscrew  62  is turned to thread to and engage hole  112 . Continuing to turn thumbscrew  62  will immobilize slide  22  within its associated track  14 .  
         [0040]    In FIGS. 5 and 6, it will be seen that slide  22  has a ridge or flange  114  which projects upwardly above upper surface  116  of slide  122 . Flange  114  serves as a stop against which an endodontic ruler  8  may be placed for making measurements in adjusting position of slide  22  within base  12  (see FIG. 1). This is a preferred embodiment which renders indicia  56  (see FIG. 2) unnecessary, although both may be provided if desired. It will be seen from examining FIG. 5 that step  55  is recessed behind the forward surface of flange  114 . Step  57  is coincident or coplanar with the forward surface of flange  114 . Steps  54 ,  58 ,  60  are located forwardly of the forward surface of flange  114 . While step  60  is shown lower than step  58 , steps  55 ,  57 ,  54 ,  58 , and  60  are considered to be generally arranged in ascending order with respect to distance to the retaining barrier. The order shown generally corresponds to the order required in the treatment procedure, thus facilitating ease of use, although other orders could be employed.  
       2. Color Coding  
       [0041]    Files (e.g., file  2  of FIG. 2) are correlated for use with each root canal by any suitable visual marking technique applied to a file holder such as gauge  10 . It is contemplated that the most practical form of marking is to place coloring permanently on the holder holding prepared files until use, and to place similar coloring on a tooth as reference marks or datum points. In the preferred invention, file holding apparatus comprises gauge  10 , which is modified to bear color coding at any suitable location thereon.  
         [0042]    [0042]FIG. 3 shows one way in which the apparatus may be color coded. As seen at the top of FIG. 3, four slides  23 ,  25 ,  27 ,  29  are each provided with pigment or other coloring of hues differing from those of other slides  23 ,  25 ,  27 ,  29 . In the example of FIG. 3, slide  23  is colored at the upper end thereof with a blue hue, slide  25  bears a green hue, slide  27  bears a red hue, and slide  29  bears a black hue. Each slide therefore has its own distinctive coloring. All files the lengths of which are set on retaining barrier  30  which are longitudinally aligned with any one particular slide (e.g.,  23 ,  25 ,  27 , or  29 ) will be readily discerned as being associated with that one slide, and that the particular slide is associated with a particular root canal in the following way.  
         [0043]    [0043]FIG. 7 shows a tooth  4  bearing reference marks or datum points  102 ,  104 ,  106 , and  108 . Each reference mark  102 ,  104 ,  106 , or  108  is established by the dental practitioner to reflect a suitable location for determining and defining radiographical length of each root canal of the operative tooth. Reference marks  102 ,  104 ,  106 ,  108  are distinctively made to exhibit hues or colors corresponding to those appearing on color coded slides (e.g., slides  23 ,  25 ,  27 ,  29 ) such that a correlation is established between each particular root canal, a particular slide, and a group of files prepared by use of the associated slide. It is then an easy matter once the procedure is commenced to set the predetermined exposed length of every file in a set that is to be used in a given root canal, by using the slide that bears the color corresponding to the color of the reference mark of the root canal being addressed at that stage of the procedure.  
         [0044]    As mentioned previously, certain portions of gauge  10  are permanently colored. Reference marks  102 ,  104 ,  106 ,  108  are each applied with a different color from that used to mark all others as part of the root canal procedure. This may be done with any suitable marking apparatus, including commercially available marking pens (not shown). Hues of the reference marks need not exactly match those of gauge  10 , provided that they are sufficiently similar to establish immediate visual correlation when viewed by the dental practitioner.  
         [0045]    It is contemplated that color is the best form of visual marking by which differentiation of groups of files may be made. However, other forms of visual or even tactile markings may be utilized instead of or in addition to color. Surfaces of gauge  10  may be, for example, textured to afford these surfaces with readily discerned sensible characteristics, such as visual or tactile characteristics, or with both. Corresponding materials may be temporarily applied to tooth surfaces so that reference marks match the file holder as this relates to sensible characteristics. It should be understood that where color coding is employed, the colors selected may be chosen to avoid any two or more colors that may appear the same or similar to a person whose visual color perception is impaired, an example being red and green, and which is readily distinguishable from the color of the tooth.  
         [0046]    The file holder need not be limited to assuming the form of gauge  10 . A file holder provided with color coding may be any device having a member which receives, sets length of, and retains files in a manner assuring visual or even tactile organization of files so that hasty retrieval of a file of a desired group of files is readily confirmed by visual or tactile feedback. The file holder could be, for example, a tray partitioned into several receptacles, provided the tray had surfaces arranged for ready recognition of files grouped according to their associated root canals. The file holder could comprise, in another example, one or more walls corresponding to retaining barrier  30 , the walls having slots or other openings for receiving files. In still another example, the file retainer could comprise a body bearing a plurality of vertical, elongated holes. The precise nature of the file retainer is unimportant, provided that it can hold files in a manner making them accessible in readily discernible groups to a dental practitioner, and provides sensible marking enabling discrimination among the various groups of files.  
         [0047]    The present invention is susceptible to variations which may be introduced thereto without departing from the inventive concept. Elements set forth in the singular may be replaced by plural elements to the same effect. Any of the variations of alternative embodiments may be combined as desired.  
         [0048]    It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.