Abstract:
A prosthodontic assembly for installing a prosthetic tooth comprises a dental implant and abutment combination and a healing cap. The combination includes an implant body portion and an abutment portion. The implant body portion is located at a distal end of the combination and is configured to lie at least partially below a crest of a patient&#39;s jawbone. The abutment portion is located at a proximate end of the combination and is configured to lie at least partially above the crest of the patient&#39;s jawbone. The abutment portion comprises a flared portion, a shoulder portion and a final restoration portion. The shoulder portion lies between the flared portion and the final restoration portion. A healing cap includes a body portion having a proximal and a distal end. The body portion defines an inner cavity which is sized and adapted so that the healing cap fits over the final restoration portion. The healing cap further includes a tissue retraction flange at the distal end that extends below the shoulder portion when the healing cap is coupled to the abutment portion.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]    The present application claims priority and benefit under  35  U.S.C. § 119 (e) of U.S. Provisional Patent Application Ser. No. 60/203,333 filed May 11, 2000, the entire contents of which are expressly incorporated herein. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The present invention relates generally to dental implants and, more particularly, to a heal in-place abutment system including a healing cap adapted to be received upon a final abutment.  
         DESCRIPTION OF THE RELATED ART  
         [0003]    Implant dentistry involves the restoration of one or more teeth in a patient&#39;s mouth using artificial components. Such artificial components typically include a dental implant and a prosthetic tooth and/or a final abutment that is secured to the dental implant. The process for restoring a tooth can be carried out in three stages.  
           [0004]    Stage I involves implanting the dental implant into the bone of a patient&#39;s jaw. The oral surgeon first accesses the patient&#39;s jawbone through the patient&#39;s gum tissue and removes any remains of the tooth to be replaced. Next, the specific site in the patient&#39;s jaw where the implant will be anchored is widened by drilling and/or reaming to accommodate the width of the dental implant to be implanted. Then, the dental implant is inserted into the hole in the jawbone, typically by screwing, although other techniques are known for introducing the implant in the jawbone.  
           [0005]    The implant itself is typically fabricated from pure titanium or a titanium alloy. Such materials are known to produce osseointegration of the fixture with the patient&#39;s jawbone. The dental implant fixture also typically includes a hollow threaded bore through at least a portion of its body and extending out through its proximal end which is exposed through the crestal bone for receiving and supporting the final tooth prosthesis and/or various intermediate components or attachments.  
           [0006]    After the implant is initially installed in the jawbone, a cover screw is secured over the exposed proximal end in order to seal the internal bore. The patient&#39;s gums are then sutured over the implant to allow the implant site to heal and to allow desired osseointegration to occur. Complete osseointegration typically takes anywhere from four to ten months.  
           [0007]    During stage II, the surgeon reaccesses the implant fixture by making an incision through the patient&#39;s gum tissues. The cover screw is then removed, exposing the proximal end of the implant. The interior of the implant is thoroughly cleaned and dried. The surgeon then attaches a temporary healing abutment or a final abutment to the implant. Typically, the healing or final abutment includes a threaded post, which is screwed directly into the hollow threaded bore of the implant. To accurately record, the position the orientation and the shape of the final abutment, the surgeon can take a mold or impression of the patient&#39;s mouth . The impression is used to create a plaster model or analogue of the mouth and the abutment and provides the information needed to fabricate the prosthetic replacement tooth and any required intermediate prosthetic components. Stage II is typically completed by securing a protective cap to the abutment with temporary cement. Alternatively, a conventional temporary restoration can be attached to the abutment.  
           [0008]    Stage III involves fabricating and placement of a cosmetic tooth prosthesis to the implant fixture. The plaster analogue provides laboratory technicians with a model of the patient&#39;s mouth and the final abutments. Based on this model, the technician constructs a final restoration. The final step in the restorative process is attaching the final restoration to the abutment.  
         SUMMARY OF THE INVENTION  
         [0009]    In accordance with one embodiment, the present invention provides for a prosthodontic assembly for installing a prosthetic tooth. The assembly comprises a dental implant and abutment combination and a healing cap. The combination includes an implant body portion and an abutment portion. The implant body portion is located at a distal end of the combination and is configured to lie at least partially below a crest of a patient&#39;s jawbone. The abutment portion is located at a proximate end of the combination and is configured to lie at least partially above the crest of the patient&#39;s jawbone. The abutment portion comprises a flared portion, a shoulder portion and a final restoration portion. The shoulder portion lies between the flared portion and the restoration portion. A healing cap includes a body portion having a proximal and a distal end. The body portion defines an inner cavity which is sized and adapted so that the healing cap fits over the final restoration portion. The healing cap further includes a tissue retraction flange at the distal end that extends below the shoulder portion when the healing cap is coupled to the abutment portion.  
           [0010]    In accordance with another embodiment, the present invention provides for a method for installing a prosthetic tooth. The method comprises inserting a distal end of a body portion of a dental implant and abutment combination into a patient&#39;s jawbone during a first stage surgery, coupling a healing cap to an abutment portion of the combination, during first stage surgery, such that a tissue retraction flange of the healing cap extends below a shoulder portion of the abutment portion, removing the healing cap from the abutment portion during a second stage surgery, and taking an impression of the combination during the second stage surgery after the healing cap has been removed from the abutment portion.  
           [0011]    In accordance with yet another embodiment, the present invention provides for healing cap for combination with a dental implant in a method of installing a prosthetic tooth. The healing cap comprises a body having a proximal end, a distal end, and a cavity thereon, sized and adapted such that the distal end will fit over an abutment, and into a mounted position with respect to the abutment. The abutment has a radially outwardly extending shoulder. The body further includes a tissue retraction surface, which extends distally of the shoulder when the body in the mounted position.  
           [0012]    For purposes of summarizing the invention and the advantages achieved over the prior art, certain objects and advantages of the invention have been described herein above. Of course, it is to be understood that not necessarily all such objects or advantages may be achieved in accordance with any particular embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein.  
           [0013]    All of these embodiments are intended to be within the scope of the invention herein disclosed. These and other embodiments of the present invention will become readily apparent to those skilled in the art from the following detailed description of the preferred embodiments having reference to the attached figures, the invention not being limited to any particular preferred embodiment(s) disclosed. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0014]    These and other features of the invention will now be described with reference to the drawings of the preferred embodiments, which are intended to illustrate and not to limit the invention, and in which:  
         [0015]    [0015]FIG. 1A is a side view of a dental implant having certain features and advantages according to the present invention;  
         [0016]    [0016]FIG. 1B is a top plan view of part of the dental implant of FIG. 1A;  
         [0017]    [0017]FIG. 1C is a cross-sectional view of the dental implant of FIG. 1A;  
         [0018]    [0018]FIG. 1D is a side view of a modified dental implant without threads;  
         [0019]    [0019]FIG. 1E-G illustrate the implant of FIGS  1 A- 1 C inserted into a patient&#39;s jawbone at three different positions with respect to a patients jawbone;  
         [0020]    [0020]FIG. 2A is a side view of a final abutment having certain features and advantages according to the present invention;  
         [0021]    [0021]FIG. 2B is another side view of the final abutment of FIG. 2A;  
         [0022]    [0022]FIG. 2C is a top plan view of the final abutment of FIG. 2A;  
         [0023]    [0023]FIG. 2D is a bottom plan view of the final abutment of FIG. 2A;  
         [0024]    [0024]FIG. 3A is a partial cross-sectional side view of a coupling screw having certain features and advantages according to the present invention;  
         [0025]    [0025]FIG. 3B is a top plan view of the coupling screw of FIG. 3A;  
         [0026]    [0026]FIG. 4A is a cross-sectional view of a healing cap having certain features and advantages according to the present invention;  
         [0027]    [0027]FIG. 4B is a bottom plan view the healing cap of FIG. 4A;  
         [0028]    [0028]FIG. 4C is a is a closer view of a section of the healing cap of FIG. 4A;  
         [0029]    [0029]FIG. 5A is a cross-sectional view of a healing cap screw having certain features and advantages according to the present invention;  
         [0030]    [0030]FIG. 5B is a top plan view of the healing cap screw of FIG. 5A;  
         [0031]    [0031]FIG. 5C is a bottom plan view of the healing cap screw of FIG. 5A;  
         [0032]    [0032]FIG. 6 is a cross-sectional view of the final abutment, the coupling screw, the healing cap and the healing cap screw coupled together;  
         [0033]    [0033]FIG. 7 is a cross-sectional view of the implant inserted into a patients jawbone with the final abutment, the coupling screw, the healing cap, the healing cap screw, and the implant coupled to the implant;  
         [0034]    [0034]FIG. 8 is a cross-sectional view of the implant inserted into a patients jawbone with the final abutment, the coupling screw, and a final restoration coupled to the implant;  
         [0035]    [0035]FIG. 9 is a cross-sectional view of a healing cap, a final abutment and an implant according to the prior art;  
         [0036]    [0036]FIG. 10 is another embodiment of a heal in-place abutment system having certain features and advantages according to the present invention;  
         [0037]    [0037]FIG. 11 is another embodiment of a heal in-place abutment system having certain features and advantages according to the present invention;  
         [0038]    [0038]FIG. 12 is yet another embodiment of a heal in-place abutment system having certain features and advantages according to the present invention; and  
         [0039]    [0039]FIG. 13 is still yet another embodiment of a heal in-place abutment system having certain features and advantages according to the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0040]    FIGS.  1 - 7  illustrate the primary components of a heal in-place abutment system having certain features and advantages according to the present invention. With initial referenced to FIGS.  1 A- 1 C, a preferred embodiment of a dental implant  10  will be described. The implant  10  is preferably sized and dimensioned to receive and support one or more dental attachments or components, which will be described in detail below. In particular, the dental implant  10  is sized and dimensioned to support a final abutment to which a final restoration can be attached. The implant  10  is preferably made of a dental grade titanium alloy, although other suitable materials can also be used.  
         [0041]    As best seen in FIG. 1A, the implant  10  includes a body portion  12 , a neck  14 , and a collar  16 . The body portion  12  is preferably tapered and includes threads  18  that mate to a preformed threaded hole or osteotomy formed in the patient&#39;s jawbone (not shown). However, it should be appreciated that the body portion  12  can also be configured so as to be self-tapping. It should also be appreciated that although the illustrated body portion  12  is tapered or conical, the body portion  12  can be substantially cylindrical. Finally, it should be appreciated that the body portion  12  can be unthreaded, as shown in FIG. 1D, if the surgeon prefers to use an unthreaded implant  10 .  
         [0042]    The collar  16  of the implant is substantially cylindrical and has a top surface  24  that is substantially flat. The collar  16  is defined in part by a vertical side wall  26  that, in the preferred embodiment, is approximately 2 millimeters in axial length.  
         [0043]    The collar  16  forms a “variable placement zone”. The length and configuration the variable placement zone allows for “variable positioning” of the dental implant  12 . That is, the surgeon can vary the height of the implant  10  with respect to the crest of the jawbone  110 . For example, the surgeon can submerge the collar  16  into the jawbone such that the top surface  24  lies flush with the crest of the jawbone (FIG. 1E).  
         [0044]    Alternatively, as shown in FIG. 1F, the surgeon can place the top surface  24  of the implant  10  slight above the jawbone for esthetics (e.g., level with the alveolar crest). In another embodiment (FIG. 1 G), the implant  10  can be placed supra-crestally. That is, the top surface  24  of the implant  10  can positioned above the crest of the jawbone without exposing the threads  18  of the body region  12 .  
         [0045]    It should, however, be noted that several advantages of the present invention can be achieved with an implant  10  that (i) does not include a variable placement zone or (ii) includes variable placement zone that is smaller or larger than the preferred embodiment. For example, several advantages of the present invention can be achieved with an implant without the neck  14  and/or the collar  16 . Similarly, the neck  14  and/or collar  16  can have dimensions that are smaller or larger than the illustrated embodiment. However, the illustrated embodiment, with the neck region  14  and collar  16 , is preferred because it best allows for the flexibility described above.  
         [0046]    As best seen in FIG. 1C, the implant  10  also includes an internal socket  28 .  
         [0047]    The internal socket  28  preferably includes a threaded chamber  30 , a post receiving chamber  32 , and an anti-rotation chamber  34 .  
         [0048]    With reference to FIGS. 1B and 1C, the anti-rotation chamber  34  has a central portion having a substantially cylindrical shape. The anti-rotation chamber  34  further includes one or more radially extending portions rotational engagement portions each comprising a channel or lobe  36  extending from the top surface  24  to the bottom of the indexing chamber  34 . In the illustrated embodiment, three engagement portions  35  are provided, each having a substantially half circular shape. As best seen in FIG. 1B, the channels  36  are situated and evenly spaced around the perimeter of the indexing region  34 . Each channel  36  may be spaced 120 degrees apart from each other channel  36 . The anti-rotation chamber  34  is designed to mate with a corresponding anti-rotation region formed on various mating components, such as, for example, a final abutment. The anti-rotation chamber  34  primarily serves to prevent relative rotation between the mating component and the implant  10 .  
         [0049]    It should be appreciated that several advantages of the present inventions can be achieved with an implant that does not include the anti-rotation chamber  34 . However, the implant  10  preferably includes the anti-rotation chamber  34  because it helps to prevent the relative rotation between the mating components (e.g., a final abutment) and the implant  10 . It should also be appreciated that the anti-rotation chamber  36  can be formed into a wide variety of other suitable shapes that may be used with efficacy, giving due consideration to the goals of providing anti-rotation of mating components.  
         [0050]    For example, the anti-rotation chamber  36  could comprise a hexagonal recess or protrusion that is situated on the top surface  18  of the implant  10 . Nevertheless, the illustrated arrangement is preferred because it provides optimal clinical efficacy, ease of use and also minimizes stress concentrations within the anti-rotation chamber  34 .  
         [0051]    The post-receiving chamber  32  lies between the anti-rotation chamber  34  and the threaded chamber  30 . The post-receiving chamber  32  may have a diameter that is less than the diameter of the anti-rotation chamber  36 . The post-receiving receiving chamber  32  may include a chamfered region  37 , which is adjacent the threaded region  30 . As will be explained below, the post-receiving chamber  32  is sized and dimensioned to receive a post that is attached to a mating dental component. The post and the post-receiving chamber  32  provide lateral support, which prevents the mating component from tipping off the implant. However, it should be appreciated that several advantages of the present invention can be achieved with an implant  10  formed without the post-receiving chamber  32 .  
         [0052]    The threaded chamber  30  lies below the post-receiving chamber  32 . The threaded chamber  30  is threaded and has a diameter that may be less than the post-receiving chamber  32 .  
         [0053]    FIGS.  2 A- 2 D illustrate a preferred embodiment of a final abutment  38  having certain features and advantages in accordance to the present invention. The final abutment  38  is preferably sized and dimensioned to mate with the implant  10  described above. It is also sized and dimensioned to support a final restoration (see FIG. 9). The final abutment  38  is preferably made of a dental grade titanium alloy, although other suitable materials can be used.  
         [0054]    As best seen in FIG. 2A, the outer surface of the final abutment  38  preferably includes an upper region  40 , a flared region  42 , an anti-rotation region  44 , and a post  46 . In the preferred embodiment, the upper region  40  is substantially smooth and tapered. The upper region  40  also has a top surface  48  that is substantially flat.  
         [0055]    Towards the bottom of the upper region (i.e., the portion nearest the flared region  42 ) is a flared portion  45  that flares outward towards a shoulder  47 . The flared region  42  extends from the ridge and connects the upper region  40  to a bottom surface  50 , which is substantially flat.  
         [0056]    The upper region  40  also preferably includes a plurality of grooves  51 . These grooves  51  help orient and prevent the rotation of a final restoration  53  (FIG. 8). Accordingly, the final restoration  53  has an inner surface that matches or engages the shape of the upper region  40  of the final abutment  38 . However, those skilled in the art will readily appreciate that the upper region  40  and the grooves  51  can be formed into a variety of other shapes that can also provide an anti-rotational interface between the final restoration  54  and the final abutment  38 . It should be appreciated that although the illustrated cross-sections of the upper region and flared region are round in modified arrangements the cross-sections can be nonround. For example, the cross-section of the upper region and flared region can have a non-round cross-section that resembles the cross-section of a natural tooth.  
         [0057]    To permanently secure the final restoration  53  , cement can be applied to the upper region  40  of the final abutment  38 . Alternatively, the final restoration  52  can be coupled to the final abutment  38  by a screw (not shown). In such an arrangement, a screw hole (not shown) can be provided on the side of the final abutment  38 .  
         [0058]    As best seen in FIG. 2A, the final abutment  38  advantageously includes an inner bore  52  that extends through the center of the final abutment  38 . The inner bore  52  is preferably defined by a first and second region  54 ,  56 . The diameter of the first region  54  is preferably slightly larger than the diameter of the second region  56 . Accordingly, a seat  58  is formed between the first and second regions  54 ,  56 . The seat  58  supports a coupling screw  60  (see FIG. 3A), which will be described in detail below. Optionally, the second region  56  can include internal capture threads (not shown.  
         [0059]    With continued reference to FIG. 2A, the diameter of the bottom surface  50  is approximately equal to the diameter of the top surface  24  of the implant  10 . Extending from the bottom surface  50  is the anti-rotation region  44 , which is sized and dimensioned to fit within the anti-rotation chamber  36  of the implant. Accordingly, as best seen in FIGS. 2B and 2D, the anti-rotation region  44  is substantially cylindrical and includes three protrusions  60 . The protrusions  60  preferably extend along the entire length of the anti-rotation region  44  and have a half circular shape. The protrusions  60  are arranged around the perimeter of the indexing region  44  approximately 120 degrees apart relative to the center axis of the final abutment  38 .  
         [0060]    As with the anti-rotation chamber  36  of the implant  10 , it should be appreciated that several features and advantages of the present invention can be achieved with a final abutment  38  does not include the anti-rotation region  44 . However, it is preferred that the abutment  38  include the anti-rotation  44  because it helps to prevent relative rotation between the implant  10  and the final abutment  38 . It should also be appreciated that the anti-rotation region  44  can be formed into a wide variety of other suitable shapes that may be used with efficacy to prevent rotation of the implant  10  and the final abutment  38 .  
         [0061]    Below the indexing region  44  is the post  46 . The post  46  is substantially cylindrical and is sized and dimensioned to fit within the post-receiving chamber  32  of the implant  10 . As mentioned above, the post  36  provides lateral support to the final abutment  38  when it is placed upon the implant  10 . However, it should be appreciated that several advantages of the present invention can be achieved with a final abutment  38  that does not include a post  45 .  
         [0062]    Turning now to FIGS. 3A and 3B, the coupling screw  62  is sized and dimensioned to extend through the inner bore  52  of the final abutment  38  and to couple the final abutment  38  to the implant  10 . As with the final abutment  38 , the coupling screw  60  is preferably made of a dental grade titanium alloy. However, other suitable materials can be used.  
         [0063]    The coupling screw  62  has an externally threaded lower region  64 . The threaded lower region  64  is sized and dimensioned to engage the threads of the threaded chamber  30  of the implant  10  (see FIG. 1C). The threaded lower region  64  can also engage capture threads that can be formed on the second region  56  of the final abutment  38 . In such an arrangement, the coupling screw  62  engage the capture threads so that the coupling screw  62  does not become disassociated as the final abutment  38  is transferred and fitted to the patient&#39;s mouth.  
         [0064]    The coupling screw  62  also advantageously includes a hexagonal recess  70  located within a head  72  of the screw  60 . The hexagonal recess  70  allows for the insertion of a hexagonally shaped tool such as a conventional Allen® wrench, which can be used to apply rotational force to the coupling screw  62 . The head  72  also advantageously includes outer threads  73 , which are formed on the outer surface  75  of the head  72 . The purpose and function of the outer threads  73  will be described below. Alternatively, the threads  73  can be formed internally within the recess  70 .  
         [0065]    FIGS.  4 A- 4 C illustrate a healing cap  76  having certain features and advantages according to the present invention. The healing cap  76  may be made of a synthetic polymer, such as, for example, polyester or Nylon. However, it should be appreciated that other suitable materials can also be used. The healing cap  76  is preferably white or close to natural tooth color so that it has a natural appearance when it is placed in the patient&#39;s mouth.  
         [0066]    The healing cap  76  includes an inner surface  77  which defines an internal cavity  78 . The inner surface  77  also defines a top opening  80  and a bottom opening  82 . The inner surface  77  is sized and dimensioned such that the that healing cap fits over the upper region  40  of the final abutment  38  as best seen in FIG. 6. With particular reference to FIG. 4C, the inner surface  77  preferably includes a stop for limiting advance of the healing cap  76  onto the abutment  38 , such as, a base surface  84  that is sized and dimensioned to rest against the flanged portion  45  of the final abutment  38 .  
         [0067]    With continued reference to FIG. 4C, the healing cap  76  also preferably includes a tissue retraction flange  86 . The tissue retraction flange  86  is sized and dimensioned such that when the healing cap  76  is placed upon the final abutment  38  it extends beyond at least the upper limit of the shoulder  47  of the final abutment  38 . The purpose and function of the tissue retraction flange  86  will be described below.  
         [0068]    With reference to FIG. 4B, the top opening  80  is preferably defined by top and bottom portions  88 ,  90 . The diameter of the top portion  88  is slightly larger than the diameter of the second portion  90 . Accordingly, a seat  92  is formed between the first and second portions  88 ,  90 . The seat  92  provides support for a healing cap screw  94  (see FIGS.  5 A-C). Alternatively, and/or in addition, the opening  80  may be flared or chamfered to provide a flared seating surface.  
         [0069]    As with the final abutment  38 , it should be appreciated that although the illustrated cross-sections of the healing cap  76  are round in modified arrangements the cross-sections can be non-round. For example, the cross-sections can have a non-round cross-section that resembles the cross-section of a natural tooth.  
         [0070]    Turning now to FIGS.  5 A-C, the healing cap screw  94  will now be described.  
         [0071]    The healing cap screw  94  is sized and dimensioned so as extend through the healing cap  76  and to couple the healing cap  76  to the final abutment  38 . The healing cap screw  94  is preferably made of a dental grade titanium alloy; although, other suitable materials can be used.  
         [0072]    As best seen in FIG. 5A, the healing cap screw  94  includes a flange  96 , an upper hexagonal recess  98 , a barrel  99  and a lower recess  100 . The flange  96  preferably has a diameter that is slightly smaller than the diameter of the upper portion  88  of the healing cap  76 . Furthermore, as seen in FIG. 6, the flange  96  is preferably sized and dimensioned such that the top surface  97  of the flange  98  sits flush with the healing cap  76 .  
         [0073]    The hexagonal recess  98  extends through the flange  96  and allows for the insertion of a hexagonally shaped tool such as a conventional Allen® wrench, which can be used to rotate the healing cap screw  94 .  
         [0074]    The threaded recess  100  is positioned on the lower end of the healing cap screw  94 . The threaded recess  100  includes threads  102  that are sized and dimensioned to match the outer threads  74  on the head  72  of the coupling screw  62 . Accordingly, as best seen in FIG. 6, the healing cap screw  94  extends through the healing cap  76  and can engage the outer threads  74  of the coupling screw  62 .  
         [0075]    Preferably, the barrel  99  has a diameter that is slightly larger than the inner diameter of the bottom portion of the healing cap  76 . The barrel  99  preferably includes a groove  101 , which is located below the flange  96  and has a diameter that is slightly smaller than the inner diameter of the bottom portion  90  of the healing cap. As such, the healing cap screw  94  can be press-fit into the healing cap  76  such that the bottom portion  90  fits into the groove  101  and the top portion  97  is flush with the top of the healing cap  76 . In this manner, the healing screw  94  is captured by the healing cap  76  and can rotate freely inside the healing cap  76 . Of course, in a modified arrangement, the healing cap screw  94  can be configured without the capture feature as shown in FIG. 6.  
         [0076]    In use, the surgeon first places the implant  10  (see FIG. 7) into the patient&#39;s jawbone during Stage I surgery. The surgeon then places the healing cap  76  over the final abutment  38  and uses the captured healing cap screw  94  to couple the healing cap  76  to the final abutment  38 . Specifically, the surgeon rotates the healing cap screw  94  so that the inner threads  102  engage the outer threads  74  of the coupling screw  62 . Accordingly, the healing cap  76  is held securely against the final abutment  38 . As will be explained in more detail below, the healing cap  76  helps to control the healing and growth of the patient&#39;s gum tissue around the implant site. The healing cap  76  also improves the appearance of the patient&#39;s mouth and provides the patient with a temporary chewing surface. If desired, the healing cap  76  can also be used to support a temporary restoration and/or may itself be shaped in the form of a temporary restoration.  
         [0077]    The patient then returns home and the implant is allowed to osseointegrate with the jawbone and the patient&#39;s gums are allowed to heal. Once the implant osseointegrates and the gums heal, the patient returns to the surgeon who takes an impression of the patient&#39;s mouth. The surgeon loosens the healing cap screw  94  and removes the healing cap  76  from the final abutment  38 . At this point, the surgeon takes the impression of the patient&#39;s mouth to record the position, orientation and shape of the final abutment within the mouth.  
         [0078]    The impression is used to make a model of the patient&#39;s mouth and to form the final restoration. As mentioned above, the final restoration  53  (see FIG. 8) has an inner surface that matches the upper region  40  of the final abutment  38 . Accordingly, in a final procedure, the surgeon can attach the final restoration  53  by slipping it onto the final abutment  38  cementing it in place and/or securing it with a screw.  
         [0079]    In a modified arrangement, the final abutment  38  can be attached during a traditional Stage II surgery. In such an arrangement, an impression of the final abutment  38  can also be made during Stage II before the healing cap  76  is attached to the final abutment  38 .  
         [0080]    As best seen in FIG. 7, one of the features and advantages of the present invention is the way the tissue retraction flange  86  controls the healing and growth of the patient&#39;s gum tissue  112  around the final abutment  38 . In comparison, FIG. 9 illustrates a prior art protection cap  150 , implant  152  and final abutment  154 . The implant  152  includes a shoulder region  156 . The protection cap  150  rests upon the shoulder region  156 . Because, the prior art healing cap  150  does not extend beyond the shoulder region  153 , the gum tissue  112  during a healing period grows near and above the shoulder region  156 . This may causes several problems. For example, when the protection cap  150  is removed, the gum tissue  112  tends to relax and fall over the shoulder region  156 . When an impression is taken of the final abutment  154 , this fallen gum tissue can compromise the accuracy of the impression. Moreover, if an impression cap such as the one disclosed in U.S. Pat. No. 5,688,123 is used, the fallen gum tissue can become pinched between the impression cap and the shoulder region  156  when the impression cap is snapped over the shoulder region  156 . This can cause discomfort to the patient. In addition, when a final restoration is attached to the final abutment  154  and implant  152 , the gum tissue can also become pinched in between the final restoration and the shoulder region  156 .  
         [0081]    In contrast, as shown in FIG. 7, the preferred embodiment of the healing cap  76  includes a tissue retraction flange  86  that extends below the shoulder  47  of the final abutment  38 . The tissue retraction flange  86  pushes the gum tissue  112  down and away from the shoulder  47 . The tissue retraction flange  86  also pushes the gum tissue  112  laterally away from the shoulder  47 . Accordingly, a gap  114  is formed between the gum tissue  112  and the shoulder  47  of the final abutment  38 . Thus, when the healing cap  76  is removed, the gum tissue is less likely to fall over the shoulder  47 . This arrangement tends to prevent patient&#39;s gums from falling over the shoulder  47  of the abutment when (i) the impression is taken, (ii) an impression cap is being attached to the abutment and/or when the final restoration  53  is attached to the abutment  38 . This results in more accurate impressions and minimal discomfort to the patient.  
         [0082]    The tissue retraction flange  86  sized and dimensioned to hold the gum tissue  112  far enough away from the shoulder  47  to achieve some or all the results described above. Generally, the tissue retraction flange  86  holds the gum tissue  112  at least about 0.25 millimeters below the shoulder, in some embodiments about 0.5 millimeters, in other embodiments 1 millimeter or greater.  
         [0083]    [0083]FIG. 10 illustrates a modified embodiment of a heal in-place abutment system having certain features and advantages according to the present invention. In this embodiment, the final abutment  38  is configured to mate with a conventional implant  200 , which includes a hexagonal protrusion  202  situated on the top  204  surface  18  of the implant  200 . Correspondingly, the final abutment  38  includes a hexagonal recess  206  that is configured to mate with the hexagonal protrusion  202  of the implant  200 . One of the advantages of this embodiment of the heal-in place abutment system is that it utilizes a conventional implant  10 .  
         [0084]    [0084]FIG. 11 illustrates another embodiment of a heal in-place abutment system having certain features and advantages according to the present invention. In this embodiment, the final abutment  38  includes a threaded post  208  that is configured to mate with a threaded chamber  210  formed in the implant  10 . Accordingly, the final abutment  38  is not coupled to the implant  10  by a coupling screw  62 . Instead, the abutment  38  is screwed directly into the implant  10 . Another feature of this embodiment is that the healing cap screw  94  includes a threaded region  211  that is configured to engage threads  213  formed in the final abutment  38 . One of the advantages of this arrangement is that it eliminates the need for a coupling screw. Moreover, the final abutment  39  doesn&#39;t need anti-rotation means such as a hexagonal protrusion or recess.  
         [0085]    [0085]FIG. 12 illustrates yet another embodiment of a heal in-place abutment system having certain features and advantages according to the present invention. In this embodiment, the implant  10  is a conventional implant that is configured to be placed supra-crestally (i.e., the top surface  24  of the implant  10  is positioned above the crest of the jawbone). The implant  10  includes a flanged surface  214 , which includes a shoulder  216 . The internal socket  28  includes a sloped region  218  and a threaded region  202 . The final abutment  38  includes a sloped surface  222  and a threaded region  224  configured to mate with the internal socket  28  of the implant.  
         [0086]    The healing cap  76  is configured such that the base surface  84  rests against the flanged surface  214  of the implant  10 . Correspondingly, the tissue retraction flange  86  is configured such that it extends beyond the shoulder  216  of the implant  10 . As with the previous embodiment, the healing cap screw  94  is configured to screw directly into the final abutment  38 .  
         [0087]    [0087]FIG. 13 illustrates still yet another embodiment of a heal in-place abutment system having certain features and advantages according to the present invention. As with the previous embodiment, the final abutment  38  is configured such that it can be screwed directly into the implant  10 . Moreover, the implant  10  includes a flanged surface  214  and a shoulder  216 . However, in this embodiment the healing cap  76  is configured to be temporary attached by an adhesive, such as, for example cement. This arrangement, therefore, does not include a healing cap screw  94  and, thus, uses less components.  
         [0088]    Certain objects and advantages of the invention have been described above for the purpose of summarizing the invention and the advantages achieved over the prior art. Of course, it is to be understood that not necessarily all such objects or advantages may be achieved in accordance with any particular embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein.  
         [0089]    Furthermore, although this invention has been disclosed in the context of certain preferred embodiments and examples, it will be understood by those skilled in the art that the present invention extends beyond the specifically disclosed embodiments to other alternative embodiments and/or uses of the invention and obvious modifications and equivalents thereof. Thus, it is intended that the scope of the present invention herein disclosed should not be limited by the particular disclosed embodiments described above, but should be determined only by a fair reading of the claims that follow.