Abstract:
Disclosed are systems and methods for removing obstructions from the root of a tooth. The system can include a removal instrument having an elongate tubular member having a beveled distal end and a window that communicates with an internal lumen. The window is located proximal to a beveled distal opening in the elongate tubular member. A plunger comprising an elongate shaft is sized to be received by the lumen of the removal instrument.

Description:
REFERENCE TO PRIORITY DOCUMENTS  
       [0001]     This application claims priority of co-pending U.S. Provisional Patent Application Ser. No. 60/718,626 entitled “Root Canal Obstruction Removal System”, filed Sep. 19, 2005. Priority of the filing date of Sep. 19, 2005 is hereby claimed, and the disclosure of the Provisional Patent Application is hereby incorporated by reference. 
     
    
     BACKGROUND  
       [0002]     Disclosed are systems and methods for removing an obstruction, such as a broken instrument, from the root canal of a tooth. It should be appreciated that the systems, methods, and mechanisms described herein can be adapted for use in other dental operations.  
         [0003]     The human tooth contains a clinical crown and root. The crown portion has a thin outer layer of enamel which covers the underlying tubular dentine. The root&#39;s outer layer is comprised of a thin layer of cementum which covers the radicular dentine. Harbored deep and generally running central within these hard tissue structures is the soft tissue called the dental pulp which provides the vascular support and neural supply for the human tooth.  
         [0004]     Throughout life, the dental pulp is vulnerable to injuries from decay, trauma, extensive dental procedures, or in certain instances, periodontal disease. These injuries singularly, or in combination, predispose the dental pulp to a cascade of pathological conditions beginning with inflammation and concluding with necrosis.  
         [0005]     When these events transpire, patients may present in a dental office with clinical symptoms which, often times, demonstrate abnormalities of the soft tissue, supporting structures, and/or exhibit radiographic evidence of bone loss. The treatment options include palliative emergency care, endodontics (i.e., root canal treatment), or extraction. In other instances patients present with signs and/or symptoms associated with a failing endodonitically treated tooth that requires retreatment or extraction.  
         [0006]     To avoid extraction of the tooth, root canal treatment or retreatment is performed. The root canal treatment is directed towards the elimination of pulp, bacteria, and irritants from the root canal system, followed by filling the canal space with an inert, biocompatible, dimensionally stable, root canal filling material. The clinical chain of treatment events are typically anesthesia and isolation procedures followed by cleaning and shaping procedures ideally culminating in three-dimensional obturation of the complex root canal space.  
         [0007]     Canal preparation is accomplished utilizing instruments commonly referred to as “files”. Manufacturers provide the doctor with a great variety of file choices ranging from different metals to flute configurations and geometries, tapers, lengths, and handle designs. Additionally, files can be used by hand or rotary instrumentation techniques. During cleaning and shaping procedures, the potential for file breakage is always present. File breakage is further impacted by the quality of manufacturing of the instrument used, the metallurgical properties of the metal from which the instrument is made, the number of times an instrument has previously been used, the degree of calcification, curvature, and length of a particular root canal system, patient cooperation, and importantly, method of use.  
         [0008]     Historically retrieving broken instruments or other intercanal obstructions, such as gates glidden drills, lentulo spirals, silver points, and obturation carriers, posed formidable challenges. A broken instrument clearly compromises the prognosis of a case. The instrument can break at any point in the canal. If the coronal end of the broken instrument is near the crown of the tooth, the instrument can be removed fairly easily using traditional or conventional techniques. However, if the instrument breaks deep within the root canal, for example, where the canal begins to bend or curve, extraction of the instrument becomes much more difficult. Currently available retrieval instruments used to retrieve broken instruments cannot reach deep into the root canal, and thus cannot be used when the broken instrument is deep within the root canal. Because the practitioner was still in the process of cleaning and shaping the root canal, there can be bacteria, pulp, endotoxins, etc. deeper in the root canal that still needs to be removed. Thus, breakage of the instrument deep within the root canal can severely impact the outcome of the endodontic procedure.  
         [0009]     Typically, the patient is faced with two options when the instrument breaks deep within the root canal. One option is extraction of the tooth. The other option is apical surgery to seal off the end of the root to prevent the bacteria, pulp, edotoxins, etc. from leaking out the end of the root canal.  
         [0010]     Over time various retrieval techniques evolved that were crude, often times ineffective, and limited by restricted space. Frequently, efforts directed towards instrument retrieval, even when successful, weakened roots due to overzealous canal enlargement, which in turn predisposed the tooth to subsequent root fractures and, ultimately, the loss of a tooth. Additionally, attempting to remove a broken instrument can lead to serious iatrogenic events, such as perforation of the root or the creation of ledges within the root canal, which can alter prognosis. If retrieval efforts are unsuccessful, cleaning and shaping procedures and obturation are compromised and the ultimate prognosis in placed in doubt.  
         [0011]     Lighting and magnification equals vision and are critically essential for safe and successful instrument removal. The introduction of the dental operating microscope has certainly allowed clinicians good looks at the problems. Traditionally, small files were used in efforts to either bypass or eliminate the broken instrument. Varying diameter tubes have been advocated and are placed over the most coronal end of the obstruction and are utilized in a variety of ways to retrieve obstructions. Tubes are attached to the obstruction by glue, mechanical friction, or internal threads which engage certain broken instruments. The most recent advancement in broken instrument removal utilizes ultrasonic systems. Specific ultrasonic instruments have evolved and play a central role in removing broken instruments. Even with all the innovations directed towards safe and successful instrument retrieval a small but statistically significant number of broken instruments can not be retrieved with existing technologies and techniques.  
       SUMMARY  
       [0012]     Disclosed are systems and methods for removing obstructions, such as broken instruments and other intercarnal obstructions, from the root of a tooth. In one aspect, there is disclosed an obstruction removal system comprising: a microtube abrading instrument having a proximal end configured to be connected to an ultrasonic generator and a distal working end having a lumen for receiving an obstruction; a removal instrument comprising an elongate tubular member having a proximal end with a handle, a beveled distal end and a lumen extending therebetween, wherein the distal end comprises a window that communicates with the lumen, the window located proximal to a beveled distal opening in the elongate tubular member; and a plunger comprising an elongate shaft that is sized to be received by the lumen of the removal instrument, the elongate shaft having a distal end and a proximal end that comprises a handle that engages the handle of the removal instrument  
         [0013]     In another aspect, there is disclosed a method of removing a dental obstruction from the mouth of a patient comprising: providing a microtube abrading instrument having a distal working end with a distal lumen for receiving an obstruction, the distal working end further comprising a cutting, filing or rasping surface; connecting the abrading instrument to an ultrasonic generator; inserting the abrading instrument into the mouth of the patient; guiding the distal lumen over the obstruction such that the obstruction is within the distal lumen of the microtube abrading instrument; activating the ultransonic generator to vibrate the distal working end, thereby removing tooth structure around the obstruction; removing the microtube abrading instrument from the mouth of the patient; inserting a removal instrument comprising an elongate tubular member having a proximal end with a handle, a beveled distal end and a lumen extending therebetween, wherein the distal end comprises a window that communicates with the lumen, the window located proximal to a beveled distal opening in the elongate tubular member; advancing the beveled distal end of the removal instrument over the obstruction so that the obstruction is inserted through the beveled distal opening, into the lumen and out the window of the removal instrument; inserting a plunger into the lumen of the removal instrument and advancing the plunger toward the beveled distal opening of the removal instrument until it comes into contact with the obstruction; rotating the plunger until it engages the obstruction; and removing the instrument and plunger from the mouth while maintaining engagement with the obstruction, thereby removing the obstruction from the patient&#39;s mouth.  
         [0014]     In another aspect, there is disclosed a kit for removing a dental obstruction from the mouth of a patient comprising the following components packaged together: one or more microtube abrading instruments of varying diameters having a proximal end configured to be connected to an ultrasonic generator and a distal working end having a lumen for receiving an obstruction; one or more removal instruments of varying diameters comprising an elongate tubular member having a proximal end with a handle, a beveled distal end and a lumen extending therebetween, wherein the distal end comprises a window that communicates with the lumen, the window located proximal to a beveled distal opening in the elongate tubular member; and one or more plungers of varying diameters corresponding to the one or more removal instruments by size, the one or more plungers comprising an elongate shaft that is sized to be received by the lumen of the removal instrument, the elongate shaft having a distal end and a proximal end that comprises a handle that engages the handle of the removal instrument.  
         [0015]     The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims. 
     
    
     DESCRIPTION OF DRAWINGS  
       [0016]      FIG. 1  shows a side view of a microtube instrument that is configured to be connected to an ultrasonic generator  
         [0017]      FIG. 2A  shows a perspective view of a tube portion of a removal instrument.  
         [0018]      FIG. 2B  shows a side view of the tube portion of the removal instrument.  
         [0019]      FIG. 3A  shows a perspective view of a handle that attaches to a proximal end of the tube.  
         [0020]      FIG. 3B  shows a cross-sectional view of the handle.  
         [0021]      FIG. 3C  shows an enlarged view of a portion of the handle.  
         [0022]      FIG. 4A  shows a perspective view of a plunger portion of the removal instrument.  
         [0023]      FIG. 4B  shows a side view of the plunger.  
         [0024]      FIG. 4C  shows an enlarged view of a tapered end of the plunger. 
     
    
     DETAILED DESCRIPTION  
       [0025]      FIG. 1  shows a side view of a microtube instrument  150  that is configured to be connected to an ultrasonic generator, such as an ultrasonic vibrator or transducer of generally well-known conventional construction. The operation and construction of ultrasonic generators are well known to those of ordinary skill in the art and are not described in detail herein.  
         [0026]     The microtube instrument  150  includes an elongate shank  155  having a connector  160  at a proximal end of the shank  155 . The connector  160  is configured for attachment to a device, such as an ultrasonic generator. The connector  160  can include at least one flat outer surface  165  that provides a place for engagement by a wrench or the like, such as for threadably tightening and loosening the microtube instrument  150  from the ultrasonic generator. The connector  160  can be separable from the microtube instrument, or may be permanently attached. The connector  160  can include a slot  175  for receipt of an indicia, such as a color coded band or ring, for identifying the microtube instrument  150 .  
         [0027]     In the illustrated embodiment, the shank  155  is bent at an angle beyond the connector  160 . Although any type of angle may be used, in one embodiment the shank  155  is bent into a contra-angle. A contra-angle comprises two separate angles as the shank  155  is first curved or bent in a first direction away from the original axis of the shank  155 , and is then bent back across the same axis. The shank  155  can also be straight.  
         [0028]     The distal region of the shank  155 , such as in the region of the working portion  195 , can include one or more indicia, such as score marks  180 . A clinician can use the score marks  180  to gauge the depth of the microtube instrument  150  into the tooth.  
         [0029]     With reference still to  FIG. 1 , a working portion  165  of the microtube instrument  150  is disposed at the distal end of the shank  155 . The working portion  165  includes various structures that provide working ability for the microtube instrument  150 . A lumen  170  is contained within the working portion  165  such that the working portion  165  is a generally hollow structure. The lumen  170  generally extends through the working portion  165  a predetermined distance. The lumen  170  can be of generally cylindrical shape such that the outer wall of the working portion has a generally fixed thickness without any openings therethrough. In another embodiment, however, the lumen  170  may be of a non-regular shape leading to the outer wall having a varying thickness along the length of the lumen  170 .  
         [0030]     In one embodiment, the working portion  165  has an outer wall that gradually reduces in diameter moving in the proximal direction from the distal end of the working portion. Thus, the distal end of the working portion  165  has the largest diameter such that the diameter of the working portion  165  gradually shrinks over the length of the working portion  165  moving in the proximal direction. In another embodiment, the working portion  165  has an outer wall that gradually enlarges in diameter moving in the proximal direction from the distal end of the working portion. Thus, the distal end of the working portion has the smallest diameter such that the diameter of the working portion  165  gradually increases over the length of the working portion  165  moving in the proximal direction.  
         [0031]     A cutting, filing or rasping surface  172  is disposed on the distal end of the working portion  165  adjacent the entrance to the lumen  170 . The cutting surface  172  is designed to remove tooth structure. The cutting surface  172  may be any type of cutting surface, comprised of any material known to those of ordinary skill in the art. This includes but is not limited to, smooth (knife) edge cutting surfaces, serrated cutting surfaces, saw-toothed cutting surfaces, abrasive surfaces, or any other surface or combination of surfaces. Further, the cutting surface  172  may continue onto the outer surface of the working portion  165  any distance along the working portion  165  as desired and may be constructed as an integral portion of the working portion  172  or may be added on the surface thereof as a coating. In one embodiment, a diamond coating is disposed on the cutting surface  172 .  
         [0032]     The depth of the lumen  170  into the working portion  165  can vary depending on the length of the working portion, the desired cutting depth available to the microtube instrument  150 , and/or the intended use of the microtube instrument  150 . In an exemplary embodiment, the distance is about 5 to about 30 millimeters, but that is by no means required and a wide variety of different depths can be used. In another embodiment, the lumen  170  extends further into the shank  155  or through the entire structure of the microtube instrument  150 . The diameter and/or cross-sectional shape of the lumen  170  can also depend on similar factors.  
         [0033]     As the lumen  170  will generally be placed over the broken end of a broken instrument during use, the cross-sectional area of the lumen may vary widely to allow a wide selection of devices to fit within the lumen  117 . In one embodiment, the cross-sectional diameter of a generally cylindrical lumen is about 0.1 to about 2.0 millimeters, but that is by no means required, and a wide variety of different diameters may be used.  
         [0034]     The microtube instrument  150  can have a size and shape that compliments a corresponding removal instrument, as described below. In one embodiment the thickness of the wall of the working portion  172  surrounding the lumen  170  is approximately 0.003 inch to approximately 0.008 inch.  
         [0035]     The microtube instrument  150  is used to cut around an existing elongate structure, without cutting into the elongate structure, so long as the elongate structure has a cross-sectional area equal to or less than the cross-sectional area of the lumen  170 . Most broken instruments will generally have an elongate structure. Therefore the microtube instrument  150  can be used to bore around a broken instrument by placing the broken instrument in the lumen  170 . Further, if the cross-sectional area of the lumen  170  and the broken instrument are relatively similar, the microtube instrument  150  will bore quite close to the broken instrument exposing at least a portion of its structure. Finally, because the microtube instrument  150  bores a circle about the broken instrument, the space which needs to be bored out around the broken instrument is generally less than it would be if another cutting instrument was used to bore out around the outside of the broken instrument. In particular, the microtube instrument  150  bores a hole of a diameter equal to the microtube working portion  170 .  
         [0036]     When used to form a space around a broken instrument trapped in a root canal, the microtube instrument  150  leaves a gap of approximately 0.0005 to 0.010 inches around the broken instrument, as opposed to a gap of about 0.025 inches for conventional ultrasonic instruments. The smaller gap size of the ultrasonic instrument  150  leaves a significant amount of dentin intact, which in turn does not weaken the dentinal wall.  
         [0037]     After the ultrasonic instrument  150  is used to form a space around the broken instrument, a removal instrument is engaged with the broken instrument and used to pull the broken instrument out of the tooth. FIGS.  24  show the components of such a removal instrument, which includes a tube  205  ( FIGS. 2A and 2B ) that is attached to a handle  210  ( FIGS. 3A-3C ). The removal instrument further includes a plunger  215  ( FIG. 4 ) that is removably positioned inside a lumen of the tube  205 , as described below.  
         [0038]     With reference to  FIGS. 2A and 2B , the tube  205  is an elongate member having an internal lumen  220 . A window  225  is disposed at or near a distal end of the tube  205 . The window  225  communicates with the internal lumen  220 .  
         [0039]     A bevel  230  is located at the distal end of the tube  205 . The bevel  230  provides the distal end of the tube  205  with a slanted surface relative to the longitudinal axis of the tube  205 . As best shown in the side view of  FIG. 2B , the bevel  230  is oriented such that a distal-most edge  227  of the bevel  230  is on the same side of the tube  205  as the window  225 . The bevel  230  has a proximal edge  238  that is on the opposite side of the tube from the window  225 . In other words, the bevel  230  is oriented such that the side of the tube  205  opposite the window  225  is shorter than the side of the tube  205  on which the window  225  is located. The bevel  230  forms an angle A. The value of the angle A can vary, although the angle A can be in the range of about 10 degrees to about 30 degrees, for example.  
         [0040]      FIG. 3A  shows a perspective view of a handle  210  that attaches to a proximal end of the tube  205 .  FIG. 3B  shows a cross-sectional view of the handle.  FIG. 3C  shows an enlarged view of a portion of the handle  210 . The handle  210  has an enlarged size relative to the diameter of the tube  205  to facilitate grasping of the handle  210  during use. The handle  210  can be manufactured of various materials. In one embodiment, the handle  210  is manufactured of a relatively soft material, such as silicone, for gripping comfort. The handle  210  can be color-coded for identification purposes.  
         [0041]     With reference to  FIG. 3 , the handle  210  has an internal opening  305  for receipt of the proximal end of the tube  205 . When the removal device is in an assembled state, the proximal end of the tube  205  is positioned within the opening  305  and secured to the handle  210 , such as by using adhesive. The proximal end of the tube  205  can be sandblasted to encourage a strong securement between the handle  210  and the tube  205 .  
         [0042]     The handle  210  also includes a seat  310  that is sized and shaped to receive a portion of the plunger  215 , as described below. The seat  310  forms an opening in the distal end of the handle such that a passageway is formed through the entire handle  210  for receipt of the plunger  215  therethrough. The seat  310  has internal walls with threads  320 . The threads  320  are configured to mate with corresponding external threads on the plunger  215 , as described below. The threads  320  can be configured to be tightened in response to counter-clockwise rotation of a complimentary-threaded instrument, such as the plunger  215 . Thus, when the plunger  215  is inserted into the handle  210 , the plunger  215  is tightened into the handle  210  by rotating the plunger  215  in a counter-clockwise direction (as opposed to rotating in a clockwise direction.)  
         [0043]      FIG. 4A  shows a perspective view of the plunger  215 , which includes an elongate rod  405  having a handle  410  at a distal end.  FIG. 4B  shows a side view of the plunger.  FIG. 4C  shows an enlarged view of a tapered end of the plunger contained within circle  4 C of  FIG. 4B . The handle  415  includes external threads  415  that are configured to mate with the internal threads  320  ( FIGS. 3B, 3C ) of the handle  210  of the tube  205 . The elongate rod  405  can be manufactured of various materials, including, for example, 13-8 MO stainless steel, 6AI-4V titanium, or other materials.  
         [0044]     The elongate rod  405  is sized to fit within the lumen  220  of the tube  205 . In one embodiment, the elongate rod  405  has a diameter that is greater than ⅔ the diameter of the lumen  220 . In an exemplary embodiment, the elongate rod  405  has a diameter that leaves no more than about 0.001 inch to about 0.0025 inch space between the outer wall of the plunger rod  405  and the lumen  220  when the rod is concentrically centered in the lumen  220 .  
         [0045]     The elongate rod  405  has a tapered end  420 . The taper is relatively short in length as opposed to a long, gradual taper. The short taper provides the end of the rod  405  with a “stout” shape as opposed to a longer, pointed shape. In one embodiment, the taper extends over a length of about 0.010 inch to about 0.030 inch. In one embodiment, the elongate rod  405  has a length such that the rod does not extend more than about 0.000 inch to about 0.010 inch past the distal end of the tube  205  when the plunger  215  is positioned within the tube.  
         [0046]     The instruments described herein can be used to remove a broken instrument (usually an elongate structure) from a tooth, such as from a root canal. Access to a proximal end of the broken instrument is the first step in the removal of a broken instrument. High-speed, friction grip, surgical length burs are selected to create straight-line access to all canal orifices. Radicular access is the second step in removal of a broken instrument. If radicular access is limited, hand files are usually used serially small to large, coronal to the broken instrument, to create sufficient space to safely introduce GG drills. These drills are then used like “brushes” to create additional space and maximize visibility above the broken instrument. Increasingly larger GG&#39;s are uniformly stepped out of the canal to create a smooth flowing funnel which is largest at the orifice and narrowest at the proximal end of the broken instrument.  
         [0047]     Once a suitable work area has been established, the clinician utilizes an embodiment of a microtube instrument  150  to circumferentially expose a short section of the broken instrument (generally about 2-3 mm). Generally, a clinician will be supplied with a kit of microtube instruments  150  having a variety of instruments scaled for the size of the working area, the tooth, and the broken instrument to be removed. The microtube instruments in this kit will generally have a working portion  195  ranging between 5-30 mm in length, and the lumens  170  will generally have internal diameters that can fit over a variety of different intracanal obstructions ranging from approximately 0.10 mm to 2.00 mm in diameter. Further, microtube instruments and removal instruments in the kit may be made from a variety of different materials including, but not limited to, stainless steel, nickel titanium, titanium, or plastics for different applications.  
         [0048]     The appropriate microtube instrument  150  for the particular situation is selected having a size and shape sufficient to reach the broken instrument and pass the proximal end of the broken instrument into the lumen  170 , generally without significant excess space. The microtube instrument  150  is inserted into the canal and the proximal end of the broken instrument is directed within the lumen  170 . Once the proximal end is within the lumen  170 , the microtube instrument  170  may be activated by the clinician. The microtube instrument  170  then bores the area surrounding the broken instrument, generally on all sides. Often, the vibration from the microtube instrument  150  loosens and/or dislodges the broken instrument.  
         [0049]     The broken instrument also serves as a guide during the boring procedure. As the broken instrument is within the lumen  170  the microtube instrument  150  will generally remain aligned over the broken instrument following its shape to direct the microtube instrument to carve out the area surrounding the broken instrument, even when the portion of the broken instrument being bored out is not visible. Further, because of the flexibility available to a microtube instrument  150 , the microtube instrument  150  can even track broken instruments that are bent or curved in their positioning, allowing for broken instruments much deeper in the canal, or in much more difficult positions, to be removed.  
         [0050]     Once a portion of the broken instrument has been exposed, the removal instrument is used to grasp the broken instrument. The clinician visually inspects the broken instrument and selects removal instrument with a tube  205  that is appropriately sized to fit over the broken instrument. In one embodiment, the obstruction has a transverse dimension that is about 20% to about 50% smaller than the lumen  225  in the tube  205 .  
         [0051]     After selecting the removal instrument for use, the clinician grasps the handle  210  and manipulates the tube  205  down into the tooth such that the tube  205  slides over the broken instrument. Thus, at least a proximal region of the broken instrument is positioned within the lumen  220  of the tube  205 . The obstruction is desirably about 20 percent to 50 percent smaller than the lumen that is placed around the obstruction. Such a size differential permits the tube  205  to be tilted back approximately 10 degrees to 20 degrees to permit the broken obstruction to protrude out through the window  225  in the tube  205 . If the broken instrument is too large relative to the lumen  220  in the tube, then the tube  205  cannot be tilted.  
         [0052]     Moreover, if the broken instrument is less than 50 percent of the lumen size, then further breakage can occur during attempted withdrawal of the broken instrument. The size of the plunger  215  is maximized to provide a maximum bite or purchase between the plunger  215  and the broken instrument. A clinician can visually examine the broken instrument and select a removal instrument that is correctly sized for the size of the broken instrument.  
         [0053]     The bevel  230  on the distal end of the tube  205  provides space that permits the tube  205  to be tilted back (in a direction opposite the location of the window  225 ) against the bevel, which causes a proximal tip of the broken instrument to protrude through the window  225 . The plunger  215  is then inserted into the tube  205  so that the threads on the plunger engage the threads on the tube. The plunger  215  is gradually tightened downward such that the distal end of the elongate rod  220  eventually contacts and engages the broken instrument. That is, the plunger  215  presses in between the broken instrument and the internal wall of the tube  205  to grab or purchase onto a portion of the broken instrument. As mentioned, the threaded portion  415  of the plunger  215  tightens in a counter-clockwise rotation into the handle  210  of the tube  205 . The broken instrument can be, for example, an endontic file. Such files typically have blades that are arranged in a clockwise spiral configuration similar to a thread that tightens in a clockwise rotation.  
         [0054]     Thus, counter-clockwise rotation of the plunger will drive the plunger  215  deeper into the tube  205  and promote engagement between the plunger  215  and the broken instrument. However, the counter-clockwise rotation will not drive the broken file deeper into the canal. To the contrary, the counter-clockwise rotation is more likely to loosen the file from the canal.  
         [0055]     Once the plunger  215  has achieved a purchase with the broken instrument, the clinician manipulates the removal instrument by gently rotating the instrument. The rotation is preferably in a counter-clockwise direction. As mentioned, such counter-clockwise rotation can cause the plunger threads  415  to tighten further into the tube  205 . Moreover, because the broken instrument tightens in a clockwise rotation, the counterclockwise rotation will not further drive the instrument into the root canal. Indeed, the counterclockwise rotation is more likely to loosen the broken instrument from the root canal.  
         [0056]     One effective method of removal is to gently turn the removal instrument, let go of the removal instrument, and then repeat the process again. The removal instrument can be gently wiggled during this process to assist in loosening of the broken instrument from the root canal. The process is repeated until the broken instrument is freed from the root canal. The broken instrument can be unscrewed from the root canal by rotating the broken instrument in a counter-clockwise direction.  
         [0057]     Although embodiments of various methods and devices are described herein in detail with reference to certain versions, it should be appreciated that other versions, embodiments, methods of use, and combinations thereof are also possible. Therefore the spirit and scope of the snowboard binding should not be limited to the description of the embodiments contained herein.