Patent Publication Number: US-2004053195-A1

Title: Healing cap and gingival emergence profiler for dental implant anchor

Description:
BACKGROUND OF THE INVENTION  
       [0001] This application is related to U.S. patent application, Ser. No. 08/606,004, filed on Feb. 12, 1996, and subsequently issued on Mar. 31, 1998, as U.S. Pat. No. 5,733,123, included herein by reference.  
       [0002] 1. Field of the Invention  
       [0003] The present invention relates to a healing cap for an implant anchor for a dental implant. After the implant anchor is implanted in bone tissue of a patient, the healing cap protects the upwardly oriented opening of the implant anchor, which will subsequently receive a post and core assembly, from being obstructed by regenerated gum tissue and other possible contaminants. Additionally, an emergence profiler surrounding the shoulder of the implant anchor and the perimeter of the healing cap prevents gingival tissue growth over the shoulder of the implant anchor, ultimately presenting a more natural appearance when the prosthetic tooth is installed.  
       [0004] 2. Description of the Prior Art  
       [0005] When an implant anchor for receiving a post and core assembly of a dental prosthesis is initially installed in a patient&#39;s jaw, care must be exercised to ensure that the opening does not become clogged due to regenerated gum tissue or other materials. A temporary sealing member, called a healing cap or cuff, is ordinarily provided for sealing the implant anchor while bone tissue grows around and solidifies the implant anchor in the jaw. Most healing caps thread into the implant anchor, which, typically, has an anti-rotational opening for receiving the post and core. After removal of the healing cap, the threads may also be used to secure the abutment in the final installation.  
       [0006] Additionally, it is desirable to prevent gingival tissue from growing over the shoulder area of the implant anchor. An emergence profiler surrounding the shoulder of the implant anchor the healing cap and held in place by the healing cap prohibits gingival growth around the implant anchor.  
       [0007] An IMPLANT HEALING CAP AND HOLDER is disclosed in U.S. Pat. No. 5,030,096, issued to Steven M. Hurson, et al., on Jul. 9, 1991. This healing cap has an upwardly oriented opening for resiliently receiving a grasping member which can be withdrawn from the cap after installation of the latter in the implant anchor. However, the opening is plain, lacking threading or other structure for the engagement of a tool or key for removing the cap when it is time for removal thereof from the implant anchor. By contrast, the present invention has structure which enables a key or like tool to engage the cap for positive retention during removal. Furthermore, the cap of Hurson, et al., has threads for engaging the opening of the implant anchor, which are absent in the present invention, and lacks the emergence profile of the present invention.  
       [0008] U.S. Pat. Nos. 5,154,612, issued to Lennart Carlsson, et al., on Oct. 13, 1992, and 5,417,570, issued to Max Zuest, et al., on May 23, 1995, both feature caps which lack threads for engaging an implant anchor. However, in both prior art examples, the cap externally surrounds the implant anchor or other part of the implant engaged by the cap. In contrast to this, the novel healing cap penetrates and engages the same opening which will subsequently be employed to receive the post and core of the prosthesis and prohibits gingival growth around the shoulder area of the implant anchor through the addition of an emergence profiler.  
       [0009] A member which penetrates an implant anchor and engages the same by friction is shown in U.S. Pat. No. 5,437,551, issued to Paul R. Chalifoux on Aug. 1, 1995. However, the top of this member is plain, lacking an opening and associated structure for engaging a key or other tool which may be employed to withdraw the member. In contrast to the device of Chalifoux, such an opening and associated structure are found in the present invention and gingival growth around the shoulder area of the implant anchor is prohibited through the addition of an emergence profiler.  
       [0010] None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.  
       SUMMARY OF THE INVENTION  
       [0011] The present invention allows easy temporary covering of the top of the implant anchor without the danger of dropping it into the mouth as is the case of conventional screws. Instead, the healing cap employs resilient resistance to compression when being inserted into the opening of the implant anchor to create friction maintaining the cap in place.  
       [0012] While this arrangement may seem much less secure than conventional threaded engagement, the fact is that little force is actually required to secure the healing cap in the implant anchor. This is because while chewing imposes strong forces which urge the healing cap into the implant anchor, there are no corresponding forces acting to remove the healing cap from the implant anchor. Moreover, the cap is only temporarily installed, and will be subsequently removed when the abutment or post and core is firmly secured within the implant anchor.  
       [0013] Temporary healing caps are generally threaded and are difficult to screw into implant anchors in the posterior areas of the mouth. It is generally desirable to minimize the amount of time it takes to temporarily cover the implant anchor. One way to accomplish this is to eliminate threading conventionally employed to secure the healing cap during its temporary placement in the implant anchor.  
       [0014] To this end, the novel healing cap has a cylindrical head from which depend legs which resiliently compress when inserted into the opening of the implant anchor. Consequent resilient expansion creates friction which secures the healing cap in place while the implant anchor is setting in the jaw.  
       [0015] A single leg may be employed in lieu of the two separated legs described above, if resilient fit with the opening of the implant anchor were sufficient.  
       [0016] An advantage of this arrangement is that the force required to unseat the healing cap from the implant anchor is minimal. Also, the motion of removing the healing cap is quite short and economical, compared to tedious unthreading of a conventional healing cap.  
       [0017] The generally cylindrical head of the healing cap has an opening at its upper or top end for receiving a tool which will be employed to extract the healing cap from the implant anchor. This opening will be threaded, if it is desired to employ a threaded key to remove the healing cap. Alternatively, grooves for engaging a key, dental pick, or other tool are inscribed on the wall of the opening in the healing cap.  
       [0018] The cylindrical head of the healing cap is of greater diameter than that of the legs, so that the legs can penetrate the opening of the implant anchor, while the cylindrical head seals the opening of the implant anchor upon abutting the implant anchor.  
       [0019] Additionally, an emergence profiler surrounds the head of the cap, covering the perimeter of the cap and the perimeter of the implant anchor. The profiler prevents the regrowth of gingival tissue around the shoulder of the implant anchor so that when the prosthetic tooth is installed it will fit between the shoulder of the implant anchor and the gingival tissue, thereby presenting a natural appearance for the prosthesis. It is easily modifiable by being made of a plastic or thin walled metal.  
       [0020] Accordingly, it is a principal object of the invention to provide a healing cap for a dental implant anchor which penetrates the opening of the implant anchor while not threading to the implant anchor.  
       [0021] It is another object of the invention to provide a leg or legs engaging the implant anchor by friction arising from resilient resistance to compression upon penetrating the opening of the implant anchor.  
       [0022] It is a further object of the invention to enhance frictional engagement of the opening of the implant anchor by providing a flange or head disposed upon the leg or legs of the healing cap.  
       [0023] Still another object of the invention is to enable engagement of the healing cap by a tool which extracts the healing cap from the implant anchor by urging the healing cap upwardly without fear of dropping it.  
       [0024] An additional object of the invention is to seal the opening of the implant anchor upon abutment of the head of the healing cap with the implant anchor.  
       [0025] It is again an object of the invention to minimize the motions and effort of extracting the healing cap from the implant anchor.  
       [0026] Yet another object of the invention is to provide an emergence profiler surrounding the healing cap which prevents regrowth of gingival tissue around the shoulder of the implant anchor, which is easily contourable to the gingival tissue so that it prevents overgrowth of the tissue without being above it where it could come into occlusal pressure, thereby allowing the prosthetic tooth to fit between the shoulder of the implant anchor and the surrounding gingival tissue.  
       [0027] It is an object of the invention to provide improved elements and arrangements thereof in an apparatus for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes.  
       [0028] These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings.  
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0029] Various other objects, features, and attendant advantages of the present invention will become more fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein:  
     [0030]FIG. 1 is an environmental, perspective, exploded view of one embodiment of the invention wherein a threaded tool is employed to extract the healing cap from the implant anchor.  
     [0031]FIG. 2 is a cross sectional detail view of the emergence profiler of FIG. 1.  
     [0032]FIG. 3 is an environmental, partially cut away, perspective view of the healing cap and emergence profiler of FIG. 1, in situ.  
     [0033]FIG. 4 is a cross sectional detail view of the head of the healing cap of FIG. 1.  
     [0034]FIG. 5 is an alternate embodiment of the head of FIG. 1.  
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
     [0035] Turning now to FIG. 1 of the drawings, the novel healing cap  10  is shown above an implant anchor  12  implanted within bone tissue  14  of a patient&#39;s jaw (not separately shown). Implant anchor  12  has a conventional hexagonal opening  16  for receiving a post and core assembly (not shown) after securement of implant anchor  12  within the jaw as a result of tissue growth.  
     [0036] Healing cap  10  comprises a cylindrical head  18  from which depends a leg comprising two leg sections  20 . Leg sections  20  are preferably complementary, separated by a slot  22  disposed therebetween, so as to collectively form a cylinder or any configuration which would cooperate with opening  16  of implant anchor  12 . In this sense, cooperation signifies that when inserted into opening  16 , leg sections  20  come to contact the wall of opening  16  in a generally compressive fashion, making contact at many points.  
     [0037] Healing cap  10  is preferably designed so that leg sections  20  are subjected to inward radial compression when inserted into opening  16 . When plural leg sections  20  are provided, they will be urged towards one another during insertion. Slot  22  accommodates the slight consequent displacement of leg sections  20  as leg sections  20  approach one another during compression. Resilience of the material forming leg sections  20  causes force to be exerted against the lateral wall of opening  16  of implant anchor  12 . This intimate contact causes friction maintaining healing cap  10  to remain within implant anchor  12 . Optionally, leg sections  20  could have threads  24  (FIG. 5) for cooperation with a threaded implant anchor  12 .  
     [0038] The result of this cooperation is that healing cap  10  will be upright within and axially aligned with respect to implant anchor  12 . Sufficient contact between leg sections  20  and the walls of opening  16  will exist as to cause enough friction to oppose ready withdrawal of healing cap  10  from implant anchor  12 .  
     [0039] Healing cap  10  is formed from any suitable material which is biocompatible, durable, and which possesses requisite resilience. Metals which are chemically stable within the environment of the mouth, such as titanium, and a variety of synthetic polymers are examples of such materials.  
     [0040] It will further be seen in this Figure that head  18  is of greater diameter than that of leg sections  20 . In this embodiment, leg sections  20  are plural in number, and have a collective or effective diameter encompassing both leg sections  20 . The collective diameter of leg sections  20  corresponds to and is slightly greater than the diameter of opening  16  of implant anchor  12 , for assuring a frictional fit between leg sections  20  and implant anchor  12 .  
     [0041] It would be feasible to provide any number of slots in order to form more than two leg sections  20 , if desired, since such an arrangement will allow all leg sections to be displaced to the center.  
     [0042] Healing cap  10  is withdrawn from implant anchor  12  after healing by the following arrangement. An opening  26  is formed in the top end  28  of generally cylindrical head  18 , and threads  30  are disposed upon the lateral wall of opening  26 . A key or tool  32  having male threads  34  corresponding to threads  30  turns into engagement with healing cap  10 , and withdraws healing cap  10  by a short upward pull. optionally, head  18  could have a plurality of horizontal grooves  27  about its perimeter (FIG. 5), grooves  27  being adapted to cooperate with a pliers type extraction tool (not shown).  
     [0043] An emergence profiler  40  (FIG. 2) surrounds head  18  of healing cap  10  and the shoulder area of the implant anchor  12 , as depicted in FIG. 3. Emergence profiler  40  is of a biocompatible, preferably polymeric, material which is chemically stable within the environment of the human mouth. Emergence profiler  40  has a body  42  which is substantially cylindrical externally, with a rounded upper shoulder  44  and tapered lower shoulder  46 .  
     [0044]FIG. 2 shows the emergence profiler in cross section. The interior of body  42  has a substantially cylindrical internal bore  48  having a diameter marginally larger than that of head  18  of healing cap  10 . The upper portion of internal bore  48  terminates at an internal ridge  50 , internal ridge  50  protruding into the interior of the bore  48 , which continues through interior ridge  50  at a marginally smaller diameter. Internal ridge  50  serves to stop head  18  of healing cap  10  from passing completely through internal bore  48  of body  42 . Below internal ridge  50 , the diameter of internal bore  48  is substantially equal to the upper perimeter of implant anchor  12  such that the shoulder of implant anchor  12  fits within body  40  and lower taper  46  transitions smoothly from the shoulder of implant anchor  12 .  
     [0045] The legs  20  of a healing cap  10  being utilized with an emergence profiler  40  must be of sufficient length to pass through emergence profiler  40  and engage the interior of opening  16  of implant anchor  12 , as is illustrated in FIG. 3.  
     [0046] In FIG. 4, threads  30  within the head  18  of healing cap  10  seen to include a helically arranged downwardly oriented surface  80 , which surface  80  is engaged by corresponding male threads  34  (see FIG. 1) of tool  32 .  
     [0047] It will occur to those of skill in the art that the invention is susceptible to various modifications and variations. For example, leg sections  20  could be superseded by a single leg. This will be acceptable provided the superseding arrangement has resilient or elastic resistance to compression upon insertion into the implant anchor  12 , or other means for enhancing engagement with its implant anchor  12 . Also, still other arrangements for engaging the healing cap for removal from the implant anchor  12  may be devised.  
     [0048] It would be further evident to one skilled in the art that emergence profiler  40  could be adapted to cooperate with any variety of implant anchor  12  known to the art without departing from the intent of the present invention.  
     [0049] It would again be evident to one skilled in the art that healing cap  10  and emergence profiler  40  could be formed as a single unit, as depicted at FIG. 3.  
     [0050] It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.