Abstract:
The invention provides an instrument and methods for minimally invasive surgical scaling and/or planning procedures, thus reducing patient recovery time. Furthermore, the present invention overcomes the shortcoming in the prior art of inadequately preparing the diseased site or creating an aerosol by providing a device that is more mechanically abrasive by way of utilizing a rotational mechanical action of a plurality of bristles.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of U.S. patent application Ser. No. 12/423,396, filed Apr. 14, 2009, and International Patent Application No. PCT/US2010/030846, filed Apr. 13, 2010, the entirety of each of which are incorporated by reference. 
     
    
     BACKGROUND 
       [0002]    This application relates generally to devices and methods for removal of diseased periodontal tissue, more particularly, to devices and methods for the removal of plaque, calculus, tartar, stain, inflamed lose soft connected tissue, top layer of adjacent bone surfaces, and/or other substances associated with periodontal disease. 
         [0003]    Any publications or references discussed herein are presented to describe the background of the invention and to provide additional detail regarding its practice. Nothing herein is to be construed as an admission that the inventors are not entitled to antedate such disclosure by virtue of prior invention. 
         [0004]    Currently dentist and periodontist treat moderate and severe periodontal disease surgically. Gingival flap surgery or a variation thereof is typically used to gain access to the diseased bone. This procedure requires that the gums be separated from the teeth and folded out of the way to allow the dentist to access the root of the tooth and/or the bone supporting the teeth. Diseased, inflamed, or otherwise unwanted tissue is removed from area around the teeth and any defects in the supporting jaw bone. Once the tissue is removed, plaque and calculus are removed by scaling and root planning. Upon completion of the surgery, the gums are placed back against the teeth and secured in place. 
         [0005]    In mild periodontal disease, the treatment typically consists solely of non-surgical scaling and root planning. Scaling and root planning, or non-surgical periodontal therapy, is a method of removing dental plaque, calculus; tartar, stain, cementum, and/or surface dentin which are thought to cause inflammation, from the root of a tooth, thereby helping to reestablish a healthy periodontal environment. The procedure is currently conducted with either ultrasonic instruments and/or hand instruments, for example, periodontal scalers and curettes. However, many ultrasonic scalers do not adequately remove diseased tissue or prepare adjacent bone surfaces for subsequent application or regenerative therapy. They also require some form of irrigation or liquid output to cool the tool while it is being used. In addition, ultrasonic scalers vibrate at such a high frequency, to remove the plaque and other material, that they create aerosols that can then spread pathogens to other areas that were previously uninfected. 
         [0006]    Currently there are no effective minimally invasive therapies for the treatment of moderate to severe periodontal disease. The invention overcomes this problem by providing an instrument and method of adequately preparing the diseased site and treating periodontal disease using a minimally invasive approach. The invention also provides a device that can be used without producing an aerosol and spreading pathogens. 
       SUMMARY OF THE INVENTION 
       [0007]    The invention provides an instrument and method that can prepare a tooth root surface, adjacent bone, and/or surrounding soft tissue with results similar to or better than the present standard for a surgical scaling and planning procedure. In addition, the present invention provides an instrument and method that is minimally invasive, thus reducing patient recovery time. Furthermore, the present invention overcomes the shortcoming in the prior art of inadequately preparing the diseased site or creating an aerosol by providing a device that is more mechanically abrasive, or does not induce the formation of an aerosol. 
         [0008]    The periodontal device of the invention has the ability to loosen and/or remove any diseased or necrosed tissue in a periodontal disease pocket adjacent to a tooth with a rotating mechanical action. 
         [0009]    The invention relates to a periodontal device comprising a motor, a drive shaft rotatably connected to the motor, a plurality of bristles detachably connected to the drive shaft and a power supply casing substantially covering at least the motor and drive shaft, wherein the device is configured such that the motor supplies rotational energy through the drive shaft to the plurality of bristles, and wherein the plurality of bristles have a maximal diameter of travel during rotation of less than about 8 mm, less than about 7 mm, less than about 6 mm, less than about 5 mm, less than about 4 mm, less than about 3 mm, less than about 2 mm, or less than about 1 mm. Optionally, the drive shaft is flexible and/or steerable, thereby allowing the operator to maneuver the bristles in a precise way in a very confined space. 
         [0010]    The invention also relates to a periodontal device where a first mating fitting is connected to the drive shaft and a second mating fitting rotatably connects the plurality of bristles, such that rotational energy from the drive shaft can be transmitted to rotational motion of the bristles. In an exemplary embodiment, the plurality of bristles may have sufficient rigidity to resist deflection due to centripetal forces associated with their rotation during operation of the device. The plurality of bristles may also have sufficient rigidity to break-up diseased connective soft tissue and the top layer of adjacent bone surfaces to prepare a site for regenerative therapy application. The periodontal device further comprising a fluid irrigation and/or a suction feature(s) for removing loose tissue. 
         [0011]    Further, the invention may employ a first sheath, wherein the plurality of bristles may be retracted within the first sheath, and, optionally, the first sheath may cover at least a part of the drive shaft up to the entire drive shaft. 
         [0012]    The invention also relates to a periodontal device coupled with an illuminating system configured to illuminate a region around the rotatable bristles, and an imaging system positioned along the length of the drive shaft such that the illuminating system illuminates tissue near the bristles and the imaging system transmits visual images of the tissue proximal to the bristles to a monitor. 
         [0013]    The invention also relates to a periodontal device comprising a plurality of rotatable bristles where the bristles may have a smooth surface, a rough surface, a rounded distal tip, a shaped distal tip, and/or a grinding or polishing material adhered to at least the distal tip. 
         [0014]    The invention also relates to a kit comprising the motor, drive shaft and a housing, along with a plurality of tips having different sizes or shapes. 
         [0015]    The invention also relates to a method of removing undesirable tissue or detritus from around a tooth, the method comprising inserting a periodontal device comprising a plurality of bristles, rotating the bristles in contact with the undesirable tissue and removing the undesirable tissue or detritus, for example, by fluid irrigation and/or a suction. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0016]    The accompanying drawings, which are hereby incorporated into and constitute a part of this specification, illustrate various embodiments of the invention and, together with the description, serve to explain the principles of the invention. In the drawings like reference numerals represent like parts: 
           [0017]      FIG. 1  is a frontal view of an exemplary embodiment. 
           [0018]      FIG. 2  is a cross-sectional view of an exemplary embodiment. 
           [0019]      FIG. 3  A is a cross-sectional view of a detachable distal end of the tip that is substantially the same size as the extension in  FIG. 2 .  FIG. 3  B is a cross-sectional view of a detachable distal end of the tip that is substantially larger than the expansion in  FIG. 2 .  FIG. 3  C is a cross-sectional view of a detachable distal end of the tip wherein the bristles have a whisk-like configuration. 
           [0020]      FIG. 4  is an expanded view of the area labeled F of  FIG. 3B , illustrating an exemplary embodiment, wherein an additional length of the bristles is held on a spool and releasably extendable trough a holding member and a clutch system that have an open position wherein the bristle can extend past the holding member to extend their length in the device and a closed position wherein the bristles are held firmly at a fixed length. 
           [0021]      FIG. 5  is an expanded view of the distal end of the tip, wherein  FIG. 5A  shows a shallow bend and  FIG. 5B  shows an approximately 90 degree bend. 
           [0022]      FIG. 6  illustrates an exemplary embodiment having a steering means, a illumination means and a viewing means, along with the bristles in the tip. 
           [0023]      FIG. 7A  is a partial cross-sectional view of an exemplary embodiment wherein the bristles are retracted within the tip.  FIG. 7   b  is a partial cross-sectional view of an exemplary embodiment wherein the bristles are extended beyond the tip. 
           [0024]      FIG. 8  is a partial cross-sectional view of an exemplary embodiment wherein an extendable sheath  90  forms a retractable cannula around the tip  4 . 
           [0025]      FIG. 9  illustrates various bristle forms.  FIG. 9A  is a partial cross-sectional view of bristle having a smooth outer surface and a rounded tip.  FIG. 9B  is a partial cross-sectional view of bristle having a rough outer surface and a rounded tip.  FIG. 9C  is a partial cross-sectional view of bristle having a shaped tip.  FIG. 9   d  is a partial cross-sectional view of bristle having a grinding or polishing material applied to the tip. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0026]    For the purposes of promoting an understanding of the principles of the invention, reference will now be made to certain embodiments and specific language will be used to describe the same. Nevertheless, it will be understood that no limitation of the scope of the invention is intended by the reference to the embodiments and that alterations and further modifications of the illustrated device, along with further applications of the principles of the invention described herein, will be recognized in light of the present disclosure by one skilled in the art to which the invention relates. 
         [0027]    The uses of the terms “a” and “an” and “the” and similar references in the context of describing the invention (especially in the context of the claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. 
         [0028]    Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, each separate value in the range is incorporated into the specification as if it were individually recited herein. 
         [0029]    All methods described herein may be performed in any suitable order unless otherwise indicated or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention. 
         [0030]    As used herein, “comprising,” “including,” “containing,” “characterized by,” and grammatical equivalents thereof are inclusive or open-ended terms that do not exclude additional, unrecited elements or method steps, but will also be understood to include the more restrictive terms “consisting of” and “consisting essentially of.” 
         [0031]    Referring to  FIG. 1 , the invention provides a device  1  comprising a tip portion  4 , a power supply body or handle  6  (which may optionally further comprise a gripping area  8  (a grip)), and a power supply  9 , where optionally all or part of the tip portion  4  may have interchangeable inserts that allow the geometry or size of the tip  4  to be changed. Extending from an opening  10  in the distal end of the tip  4  are a plurality of bristles  12 , each having a proximal end  13  connected to a drive shaft (not shown) within the tip, and a distal end  14  where centripetal force due to rotation of the bristles  12  extends the distal end  14  of the bristle  12  away from a center axis running along line  15 - 15 . Alternatively, the bristles  12  may have a pre-formed shape that remains substantially unchanged in response to centripetal forces produced by rotation of the bristle  12  around the central axis  15 - 15 . 
         [0032]    It will be appreciated that the illustrated shape of the power supply body or handle  6 , grip  8  and tip  4  are merely exemplary and that the handle  6 , grip  8  and tip  4  can be formed to have any desirable shape. Preferably, the shapes of the handle  6 , grip  8  and tip  4  are such that the device  1  is ergonomically efficient and pleasant to handle by the user. 
         [0033]    Referring to  FIG. 2 , the device  20  may comprise a source of rotational force, such as an electrical, pressurized air turbine or other known motor  22 , which directly or indirectly connects with a drive shaft  23  located within the tip  4 . For example, the motor  22  may be an electrical motor  24  (e.g., a DC motor  24  having a battery source  24 ′) that may be connected indirectly to the drive shaft  23  by way of a motor shaft  25  terminating in a motor gear  26  designed to engage a gear  28  that is connected to the drive shaft  23 . In this configuration a gear box may be inserted between the motor  22  and the drive shaft  23  allowing for the control of rotational speed of the bristles  12  by way of selecting an appropriate gearing ratio. Alternatively, the motor  22  may be directly connected to the drive shaft  23 . The rotation speed of the drive shaft may be controlled and/or varied according to any known methods or devices, including the use of motors  22  and circuits described in U.S. Pat. No. 6,329,783, and the like 
         [0034]    The tip  4  may comprise a unitary elongate member connected to the power supply body or handle  6 , as illustrated in  FIG. 1 . Alternatively, the tip  4  may be connected to the motor indirectly, for example the tip  4  as illustrated in  FIGS. 3A-C  may be snap fitted onto extension  30  illustrated in  FIG. 2 . 
         [0035]    In these embodiments utilizing a detachable tip  4  ( FIG. 3A ), the drive shaft  23  will have to be detachably coupled to the rotatably mounted bristles  12  (FIGS.  2  and  3 A-C). For example, the drive shaft  23  may terminate at or in a first mating fitting  32  that is adapted to mate with a second mating fitting  34 . In FIGS.  2  and  3 A-C the first mating fitting  32  is illustrated as a relatively square block  32  connected to the drive shaft  23  and the second mating fitting  34  is illustrated as a relatively square shaped socket  34 , wherein the socket  34  is adapted to receive the block  32  and thereby couple the rotational force applied to the drive shaft  23  to the bristles  12 . As will be recognized, the mating fittings  32 ,  34  may be of any shape or size. The second mating fitting  34  may be contained in a rotational member  35  which directly or indirectly connects with the bristles  12 , and secures rotation of the bristles  12  in a plane substantially parallel with the plane defined by the opening  10  in the distal end of the tip  4 . 
         [0036]    The tip  4  may be adapted to detachably connect to an extension  30  and the motor  22  through any mechanism know in the art, for example, by way of a frictional snap fitting using a ridge  36  on the outer surface of extension  30  and groove  37  on the inner surface of the tip  4 . 
         [0037]    The tips  4  in  FIGS. 3A-C  comprise a cylindrical wall  38  having an outside surface  38 ′ and an inside surface  38 ″. In  FIG. 3A  the diameter of the inside surface  38 ″ of the cylindrical wall  38  remains relatively constant from the top of the cylinder  39 ′ to the bottom of the cylinder  39 ″. The top of the cylinder  39 ′ is, as discussed herein, configured to detachably connect to the extension  30  and the drive shaft  23  such that the bristles  12  can be rotated in the direction “R.” In  FIG. 3B  the top  39 ′ of the cylindrical wall  38  is still sized to receive the extension  30 , however, the bottom of the cylinder  39 ″ has a larger diameter than the top of the cylinder  39 ′, thereby providing a tip  4  with a larger working area. Likewise, the bottom diameter  39 ″ may be smaller than the top of the cylinder  39 ′, thereby providing a tip  4  with a smaller working area. Thus, the invention provides a kit comprising a set of tips having different sized working areas or bristles  12  made of different material. As will now be understood in light of the present disclosure, the working area of the tip will be defined by the outermost path during rotation of the distal end of the bristles  12 . In an exemplary embodiment, the tip(s)  4  have a working area of less than about 8 mm, less than about 7 mm, less than about 6 mm, less than about 5 mm, less than about 4 mm, less than about 3 mm, less than about 2 mm or less than about 1 mm. 
         [0038]    The bristles  12  may be made of almost any material, such as stainless steel, nickel alloys like Nitinol or plastics. The primary consideration in selecting the material will be its impact resistance, brittleness, hardness and elasticity. For example, if the device  1  is to be used for roughening the surface of the adjacent bone, the material needs to be hard enough to cut into bone. In contrast, if the device  1  is to be used to remove only necrosed soft tissue and some plaque, the material should be relatively soft and have a high elasticity. 
         [0039]    In an exemplary embodiment, the device may be configured using an induction motor  22  and a variable frequency controller (not shown) to allow the user to adjust the rotational speed of the bristles  12 , for example, the device  1  may operate at low speed, medium speed or high speed, alternatively the rotational speed my be set at any speed between zero revolutions per minute to the maximum number of revolutions per minute for the particular motor  22  and any associated gears  26 ,  28 . 
         [0040]    While  FIGS. 2-3  illustrate a detachable fitting having a ridge  36  and groove  37  connection, in light of the present specification it will now be apparent that the connection between the tip  4  and extension  30  may be of any size or structure. For example, the tip  4  and extension  30  may be detachably coupled using any of the known ferrule systems, threaded coupling, snap fit or other known attachment systems. The detachability of the tip  4  allows for the use of multiple differentially sized tips  4 , bristles  12  made from different materials or tips  4  and/or bristles  12  having different patterns and/or properties, which provides the ability to incrementally remove damaged tissue, plaque and calculus as desired. 
         [0041]    In  FIG. 4  the bristles  12  are illustrated seated in a clutch type devise  40 , where a clutch plate  42  can be disengaged to allow the bristles  12  to extend up though a retaining member  44  and further out the distal end  10  of the tip  4 . Rotational force exerted on the bristles  12  can be used to provide the force necessary for extension past the clutch plate  44  and up through the retaining member  44 . Thus, the bristles  12  may be held in place and selectively released for extension using any known line feed system (see U.S. Pat. No. 4,136,446). 
         [0042]      FIG. 5  illustrates that the tip  4  may be shaped according to the applicable use. For example, the tip  4  may have a moderate bend angle ( FIG. 5A ) between 1 and 85 degrees, for example less than about 10°, 15°, 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55°, 60°, 65°, 70°, 75°, 80°, or 85°, or the tip  4  may have a sharp bend angle of about 90°, for example between about 95° and 85°. 
         [0043]    In  FIG. 6 , the present invention provides a device comprising a plurality of rotatable bristles  52 , in combination with an illuminating system or means  54 , such as light-emitting diodes or fiber optic light guides connected to a light source  56  so as to illuminate the region around the rotatable bristles  52 , and an imaging system or means  58 , such as a miniature video camera or a fiber optic image guide. These components are positioned along the length of the rotatable shaft  60  that connects the rotatable bristles  52  with a motor  62 , wherein the rotatable shaft  60 , illuminating system or means  54  and the imaging system or means  58  comprise a unified flexible member that may be steered through tissue in the oral-maxillofacial area. Examples of illuminating systems, imaging systems and steerable tips may be found in U.S. Pat. No. 7,479,106 and U.S. Pat. No. 7,448,995. 
         [0044]    Thus, the device  1  may be inserted through a cannula and the tip  4  of the device  1  then steered toward the target tissue, for example, the tip  4  may be deflected a predetermined number of degrees relative to the cannula, thereby allowing the tip  4  and brushes  12  to approach the target tissue approximately perpendicular to the target tissue surface. 
         [0045]    In an exemplary embodiment the device  1  and/or the tip  4  can be sterilized using steam and pressure, e.g., by autoclaving, wherein the device  1  is now substantially free of bacteria or viral contaminants. 
         [0046]    In an exemplary embodiment, the invention involves the use of a small bristles  12  extending substantially parallel to the drive shaft, having an appropriate degree of elasticity, and that expand in diameter once extended beyond the end of a channel  70  into the periodontal area to be cleaned ( FIGS. 7A and 7B ). Expansion of bristles  12  may be due to either centripetal force and/or a pre-formed shape. The rotating action of the bristles  12  prepares the surfaces of the root and adjacent bone by scrapping off any bacterial film, necrotic tissue, plaque, calculus, stain, cementum, and/or dentin. In addition, the bristles  12  may be used to roughen the surface of the bone. The invention may be designed to both break-up and remove dislodged material, for example, by applying a vacuum. In another exemplary embodiment, the invention may be configured to dislodge or breakup primarily soft tissue, for example, lose soft tissue as opposed to healthy soft tissue, and a minimal amount of hard tissue within the area to be treated or the disease pocket/cavity. The instrument can specifically be design to remove only unwanted tissues by use of optimal material for the bristles  12  and adjustment of their rotating speeds. The generated debris particles may be aspirated out of the defect area using a separate irrigation and/or suction device via a channel incorporated into the device (not shown). The device may also be inserted through a cannula in order to access the proper dental site. Alternatively, the device may have and extendable sheath  90  that has a leading edge  92  that is capable of being extended beyond the distal end of the main channel  70  so as to form a retractable cannula tip  92 . In  FIG. 8 , the extendable sheath  90  has an inner diameter that is large enough to surround and slide along the outer surface  102  of the channel  70 , wherein the drive shaft  104  is rotatably held in the channel  70 . 
         [0047]    In  FIG. 9A-D  variations on the bristles  120  are illustrated.  FIG. 1A  illustrates a bristle  120  that has a smooth surface  122  and a rounded tip (distal end)  124 .  FIG. 1B  illustrates a bristle  120  that has a rough surface  126 .  FIG. 1C  illustrates a bristle  120  that has a squared or sharp angle tip (distal end)  128 .  FIG. 1D  illustrates a bristle  120  that has a grinding or polishing material  124  applied to the distal end. The shape of the distal end may be any desirable and appropriate shape, the surface of the bristle  120  may be smooth or rough, appropriate and desirable materials may be applied to the distal end of the bristles  120  and combinations thereof. 
         [0048]    In another exemplary embodiment, the invention provides a method of treating a periodontal defect by inserting the tip  4  and using the bristles  12  to clean any bacterial film, plaque, necrotic tissue or other deleterious material surrounding a tooth, tooth socket, or alveolar ridge, and then applying a therapeutic agent to the area between the tooth and surrounding soft tissue. For example, a biological agent such as the GDF-5, BMP-2, BMP-4, BMP-6, BMP-7, BMP-12, TGF-β1, LMP-1, IGF-I, and/or other members of the transforming growth factor-beta (TGF-β) superfamily, can be inserted down the cannula or via a needle after the cannula has been removed. 
         [0049]    In another exemplary embodiment, a cannula may be placed through the gum of a patient with periodontal disease via a very small hole rather than surgically cutting and reflecting back the gum tissue. A device  1  according to the invention may then be inserted through the cannula and used to prepare the site by removing bacterial film, necrotic tissue, plaque, stains, calculus, cementum and/or roughening the bone surface 
         [0050]    The device of the present invention may be used at a low power, i.e., low rotational speed or centrifugal force, to remove plaque, soft tissue and other lower density material and the power, rotational speed or centrifugal force, may be increased in response to harder material, such as calculus. 
         [0051]    The instrument may also have depth measurement guides on the outer surface and mechanical stops to limit its depth of penetration into the periodontal defect. Alternate mechanical preparation of the periodontal defect can be used such as an ultrasonic probe or other types of tissue ablators. 
         [0052]    While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected. In addition, all publications cited herein are hereby incorporated by reference in their entirety.