Abstract:
A flexible or adjustable housing for a surgical needle and a needle assembly that includes the housing. Adjustment of the length of the housing allows the needle to accommodate tooth canals of varying lengths, while providing the requisite support for the needle, without needing to adjust the actual length of the needle.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates to medical and dental needles and, more specifically, to housings and guards for those needles. 
         [0002]    Endodontic or root canal therapy is a common procedure in which a dentist or endodontist removes the nerve and dental pulp from a tooth in cases where the nerve has been damaged by a cavity, trauma (e.g., fracture of the tooth), disease (e.g., infection), or other reasons. This procedure not only allows the individual to keep a tooth that otherwise might have needed removal, but relieves the individual of pain and discomfort. 
         [0003]    When working within a root canal, a needle is used for evacuation and/or irrigation purposes. Needles are generally flexible or pliable so that they conform to the shape of the root canal. Usually the needle is inserted into the root canal until the end of the needle is a few millimeters or less from the apex of the tooth&#39;s root. This is to insure that the canal is properly debrided. However, each of the individual canals is not uniform from one to another, and the length of each individual root canal varies from canal to canal. Typically, a tooth will contain between 1-5 canals. Consequently, the length of a needle is normally adjusted to address each individual root. 
         [0004]    The length of the needle is generally adjusted by cutting the needle to the necessary length for an individual root. Since a needle is used in multiple canals, the needle will be sized to the longest root, and then be cut down to the lengths of the other roots. However, it may not always be easy to properly assess the length of a root, or a longer root may need to be revisited during a procedure. In such instances, the shortened needle may not adequately address the longer root, which requires using a new needle. A new needle must be used, and then the needle must be properly sized, which requires extra time and, also, extra expense for the extra needles. 
       SUMMARY OF THE INVENTION 
       [0005]    The present invention provides a flexible or adjustable housing for a surgical needle and a needle assembly that includes the housing. The housing generally comprises a first section that connects the housing to a fluid line or fluid lines, such as evacuation and irrigation lines. 
         [0006]    The housing also has a second section connected to the first section, which provides an adjustable length for the housing. Adjustment of the length of the housing allows the needle to accommodate tooth canals of varying lengths, while providing the requisite support for the needle, without needing to adjust the actual length of the needle. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  is a cross-sectional view of a typical tooth and its environment. 
           [0008]      FIG. 2  is a cross-sectional view of the tooth of  FIG. 1 , with a prior art needle being inserted into a root canal of the tooth. 
           [0009]      FIG. 3  depicts the length of a prior art needle being sized for insertion into a different root canal within the tooth. 
           [0010]      FIG. 4  is a cross-sectional view of the needle of  FIG. 3  being inserted into a second root canal of the tooth in  FIG. 1 . 
           [0011]      FIG. 5  is side elevation view of a needle and housing assembly according to the present invention. 
           [0012]      FIG. 6  is a cut-away view of the needle and housing assembly of  FIG. 5  being inserted into the tooth shown in  FIG. 1 . 
           [0013]      FIG. 7  is a second cut-away view of the needle and housing assembly of  FIG. 5  being inserted into the other root canal of the tooth shown in  FIG. 1 . 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0014]    Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention which may be embodied in other specific structures. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims. 
         [0015]      FIG. 1  depicts a typical tooth  10  for which a procedure will be performed on the tooth  10 , such as a root canal or other endodontic procedure. The tooth  10  is depicted as having two root canals  12  and  14 , each having a respective apex  16  and  18 . The root canals  12  and  14  are shown as being of different lengths, which is typical for a tooth. For example, a tooth may have two, three, four, or five roots and root canals, with the roots ranging in a length from about 10-45 mm, or of a greater or shorter length. Regardless of the number of roots within the tooth and the length of each of the individual roots and canals, it is desirable when performing a procedure that a needle is inserted a consistent depth from the apex of an individual root, regardless of the length of the individual root canal. For example, to properly debride a root, the tip of a needle preferably would come within about 1 mm from the apex so that air pockets are not formed that inhibit the process. 
         [0016]      FIG. 2  shows a needle  20  being inserted into the root canal  12  so that the tip  22  of the needle  20  is close (i.e. ˜&lt;1 mm) from the apex  16 . The needle  20  extends outwardly from a housing  24 . Because the needle  20  is preferably a flexible or bendable, the housing  24  is necessary so that the needle  20  is properly inserted into the root canal  12  without bending or crimping prior to insertion, with the housing  24  generally being positioned or resting at or close to the top  25  of the root canal  12 . Ideally, the section of the needle  20  extending outwardly from the housing  24  is only approximately the length that is necessary for the needle to reach the apex  16  (within ˜1 mm) of the root canal  12 . 
         [0017]    As previously stated, the individual root canals are of differing lengths, and the needle  20  is preferably adjusted to the specific root length.  FIG. 3  shows the needle  20  being adjusted by cutting the length of the needle  20  with the use of scissors  26 . The needle  20  is typically of a small enough diameter and malleable enough material that it can be cut with simple cutting devices, like scissors, utility knives, or razor blades. Alternatively, the length of the needle  20  that extends outwardly from the housing  24  can also be adjusted by cutting the housing  24  itself. 
         [0018]    Once adjusted, the needle  20  will be inserted into the root canal  14 , with the tip  22  being situated close to the apex  18  of the root canal  14 , as shown in  FIG. 4 . The housing  24  is positioned on or near the top  27  of the root canal  14 . The root canal  14  will then be debrided, and the needle  20  will be removed and can be inserted into another root canal, if necessary, with the needle  20  length to the length of the new root canal. This process can be arduous and may result in the use of more needles than necessary, particularly if a needle has been cut to the wrong length. 
         [0019]      FIG. 5  provides a cut-away plan view of a dental assembly  100  according to the present invention. The assembly  100  alleviates the problems and time needed to adjust the length of a needle for proper insertion into a root canal. The assembly generally comprises a housing  102  with a needle  104  extending outwardly from the housing  102 . The housing  102  has a first section  106  and a second section  108 . The housing  102  has at least one pathway  110  for the needle  104  to be situated within and a second pathway  112  in communication with evacuation means, such as a vacuum (not shown). A tubing  114  may connect the second pathway  112  to an evacuation pathway  116 , which will be connected to the evacuation source. The pathway  110  provides for fluid delivery, which may be accomplished internally or externally of the needle  104 . 
         [0020]    Still referring to  FIG. 5 , the first section  106  has a first end  114  that allows the housing  102  to be connected to an adaptor  120 , which is subsequently connected to a handpiece  122 . The arrangement allows for the needle  104  and/or the pathway  110  to be in fluid communication with a pathway  124  located within the handpiece  122 . Alternatively the first end  114  may be directly connected to the handpiece  122 . 
         [0021]    Referring further to  FIG. 5 , the first section  106  has a second end  126  where the first section  106  is connected to the first end  108 . The first section  106  and the second section  108  can be formed as separate sections and adhered together, or they can be molded or formed as a single piece. The second section  108  comprises a flexible body  128 , which will allow the overall length of the housing  102  to be adjusted. Preferably, the flexible body  128  has an accordion-style body, such as a bellows shaped area. The flexible body  128  will be discussed further with respect to  FIGS. 6 and 7 . 
         [0022]      FIG. 6  demonstrates the assembly  100  being used, with the needle  104  being inserted into the root canal  12 . The tip  130  of the needle  104  is positioned near the apex  16  of the root canal  12 , just as the prior art needle  20  shown in  FIG. 1 . The flexible body  128  that generally comprises the second section  108  is buttressed against the top  25  of the root canal  12 . The body  128  is compressed to allow the needle  104  to reach near the apex  16 . 
         [0023]      FIG. 7  shows the assembly  100  and the needle  104  being used in the root canal  14 . The tip  130  of the needle  104  is located near the apex  18 . The flexible body  128  is shown buttressed against the top  27  of the root canal  14 . However, as compared to the assembly  100  as shown in  FIG. 6 , the body  128  is not compressed but in an extended position. In both depictions ( FIGS. 6 and 7 ), the housing  102  provides support for the extent of the needle  104  that extends outwardly of the specific root canal  12 ,  14 . The needle  104  is properly sized for use in either root canal  12 ,  14 , without either the needle  104  or the housing  102  needing to be cut to size. That is, the needle  104  will be properly supported by the housing  102  while still reaching the necessary depth within a specific root canal, regardless of the length of the root canal, without any modifications necessary to the assembly  100 . The arrangement not only provides for proper sizing of a needle within a root, but also provides for a quicker, more efficient process. The user does not have to measure and size the needle for different roots, which reduces the time needed for a procedure and, also, provides for a more accurate required length. Similarly, because it is not necessary to determine the length of the needle  104  in the present invention for use in a specific root canal, fewer needles will be used, which is cost effective. 
         [0024]    This is also relevant when a user is revisiting a root where a procedure has already been performed. Because prior art needles were cut to length for each root canal, the user would need to work from the longest root canal to the shortest. Returning to a prior root canal required a new needle, as the needle being used would not have sufficient length to reach the apex of the prior, longer root canal. The present invention allows for going back to a previous root, since the overall needle length is not altered. The housing  102  is capable of adjusting to the length of each of the root canals being operated upon, while still providing the necessary support for the needle  104 . The housing  102  length can be made longer or shorter, as necessary, while still being capable of returning to a different or previous housing length. The length of the adjustable portion of the housing may be adjusted, as necessary. 
         [0025]    It is understood that the scope of the present invention is not limited by the evacuation/irrigation arrangement of the attached dental tool. For example, typically irrigation fluid is delivered to a root canal through the needle  104  and evacuated outside of the needle through the housing  102 . However, there are devices and tools having an opposite arrangement, wherein irrigation fluid would be delivered through the housing, and the fluid is evacuated by the needle. The evacuation and irrigation in either arrangement may be performed simultaneous, as well. Provided that the arrangement provides for a flexible housing for the needle as disclosed, either arrangement falls under the scope of the present invention. 
         [0026]    The foregoing is considered as illustrative only of the principles of the invention. Furthermore, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.