Abstract:
A dental implant system can include an upper implant body coupled to a lower body with a cavity between the upper and lower implant bodies. The system can further include an anchor at least partially disposed within the cavity. The system can also include an abutment that couples to the anchor and serves as a mounting area for a crown. The anchor can be rotatable and swivelable, allowing the lower implant body to be implanted at an angle in bone while permitting the crown to be positioned in a natural tooth orientation.

Description:
RELATED APPLICATIONS 
       [0001]    This application is a continuation of U.S. patent application Ser. No. 14/191,363, filed on Feb. 26, 2014, which is a continuation of U.S. patent application Ser. No. 13/447,121, filed on Apr. 13, 2012, now U.S. Pat. No. 8,684,733, which claims the priority benefit of U.S. Provisional Applications No. 61/476,230, filed on Apr. 15, 2011, No. 61/487,591, filed on May 18, 2011, No. 61/512,366, filed on Jul. 27, 2011, and No. 61/545,061, filed on Oct. 7, 2011, all of which are hereby incorporated by reference in their entirety. 
     
    
     BACKGROUND 
       [0002]    The subject technology generally relates to dental implants. 
         [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 an implant body, an abutment, and a crown. The completed assembly is referred to as a dental implant. 
         [0004]    The implant body is the part of the dental implant that provides the anchor or foundation for the restoration. This part is fixed in the jaw bone, and can be threaded or non-threaded. Bone tissue tends to grow around the implant body and thus the jaw bone is strengthened. Commercially available implant bodies are typically made of either commercially pure titanium or a titanium alloy and, depending on the need, may be coated with hydroxyapatite to promote osseointegration. The abutment is the portion of the dental implant that attaches to the implant body and extends above the gumline and provides internal support to the artificial crown. The crown is the topmost part of the restoration and is the part that is visible in the mouth. Crowns for dental implants are similar to crowns applied over natural teeth and are usually made of metal or porcelain or a mixture of the two.  FIGS. 1 and 2  illustrate two examples of existing dental implants. 
         [0005]    Temporary components used during the implantation procedure include a healing screw and a healing cap. The healing screw is used after the implant body is initially placed while the soft tissue over the implant body is healing. The healing screw facilitates the suturing of the soft tissue and also prevents the growth of tissue over the edge of the implant. A healing cap is a dome-shaped cap that projects through the soft tissue into the oral cavity and further guide the growth of gum tissues around the implant body. 
         [0006]    Generally, the process for restoring a tooth is carried out in four steps—diagnosis, implantation, attachment of the abutment, and attachment of the crown. During the diagnosis in Step  1 , an X-ray image is typically taken of the patient&#39;s head to determine the shape and density of the bone structure of the jaw. In certain circumstances, a CAT scan may be required to provide more detailed information about the bone and the location of structures such as sinuses. 
         [0007]    Step  2  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. 
         [0008]    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. Existing dental implant typically include 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. 
         [0009]    After the implant is initially installed in the jawbone, a temporary healing 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 body and screw to allow the implant site to heal and to allow desired osseointegration to occur. Complete osseointegration typically takes anywhere from four to ten months. 
         [0010]    Step  3  is shown in  FIG. 3A . The surgeon reassesses the implant fixture by making an incision through the patient&#39;s gum tissues. The healing screw is then removed, exposing the proximal end of the implant, and the abutment is attached to the implant body. Typically, an impression is then taken of the patient&#39;s mouth to accurately record the position and orientation of the implant and abutment within the mouth. This impression is used to create a plaster model or analogue of the mouth and/or the implant site and provides the information needed to fabricate the prosthetic replacement tooth and any required intermediate prosthetic components. Step  3  is typically completed by attaching a healing cap to the abutment to control the healing and growth of the patient&#39;s gum tissue around the implant site. 
         [0011]    Between step  3  and step  4 , a crown is fabricated from the plaster model created in step  3 . Step  4  in the restorative process includes removing the temporary healing cap and attaching the crown to the abutment as shown in  FIG. 3B . 
       SUMMARY 
       [0012]    One limitation of current dental implants is that the implant body is aligned vertically, i.e., substantially perpendicularly, under, i.e. deep to, the tooth being replaced. In certain patients, especially a patient with osteoporosis, the bone structure and density immediately under the location of the tooth to be replaced may not be sufficient to provide adequate attachment to the implant body. In such a situation, it would desirable to be able to angle the implant body relative to a vertical line at the location of the tooth to be replaced. 
         [0013]    Another limitation of current dental implants is that the abutment projects from the gum sufficient that a healing cap is often necessary to guide the healing of the gum around the abutment. The healing cap may be intrusive and present an opportunity for the accumulation of food and plaque that may interfere with proper healing. It would be desirable to avoid having to place an external healing cap over the abutment while providing a temporary element through the gum that would allow the gum to heal in this area. 
         [0014]    Various exemplary embodiments of a dental implant system that addresses the above limitations are disclosed herein. The subject technology is illustrated, for example, according to various aspects described below. Various examples of aspects of the subject technology are described as numbered independent and dependent clauses (1, 2, 3, etc.) for convenience. These are provided as examples and do not limit the subject technology. It is noted that the features of any of the dependent clauses may be combined alone or in any combination into any of the independent claims or combined with other dependent claims so as to describe a particular embodiment. 
         [0015]    Clause 1. A dental implant system comprising: a lower implant body configured to be implanted in bone; an upper implant body configured to couple to the lower implant body, thereby forming a cavity between the upper and lower implant bodies, the upper implant body comprising an opening to the cavity; and a rotatable, swivelable anchor comprising: a base disposed at least partially within the cavity, the base comprising a first substantially spherical surface; and a shaft coupled to the base and extending through the opening. 
         [0016]    Clause 2. The dental implant system of clause 1, wherein the lower implant body is configured to sustain an insertion torque of at least 20 N·cm. 
         [0017]    Clause 3. The dental implant system of clause 1, wherein the upper implant body further comprises an internal surface configured such that the first substantially spherical surface is at least partially in contact with the internal surface when the upper and lower implant bodies are coupled together with the base of the anchor disposed within the cavity. 
         [0018]    Clause 4. The dental implant system of clause 3, wherein the internal surface comprises a second substantially spherical surface. 
         [0019]    Clause 5. The dental implant system of clause 4, wherein the opening passes through the second substantially spherical surface. 
         [0020]    Clause 6. The dental implant system of clause 1, wherein: the lower implant body comprises an anti-rotation post configured to project into the cavity when the upper and lower implant bodies are coupled together; and the base further comprises an anti-rotation cavity configured to engage the anti-rotation post when the base of the anchor is disposed within the cavity; and the anti-rotation post and anti-rotation cavity are configured to resist rotation of the anchor about a centerline of the lower implant body while allowing rotation of the anchor about axes perpendicular to the centerline. 
         [0021]    Clause 7. The dental implant system of clause 6, wherein: the anti-rotation post comprises a hex ball; and the anti-rotation cavity comprises a hex pocket. 
         [0022]    Clause 8. The dental implant system of clause 1, further comprising an abutment configured to couple to the shaft of the anchor. 
         [0023]    Clause 9. The dental implant system of clause 8, wherein: the upper implant body further comprises an external third substantially spherical surface; and the abutment comprises a fourth substantially spherical surface configured such that the fourth substantially spherical surface is at least partially in contact with the third substantially spherical surface when the upper and lower implant bodies are coupled together with the base of the anchor disposed within the cavity and the abutment coupled to the shaft of the anchor. 
         [0024]    Clause 10. The dental implant system of clause 8, wherein: the shaft of the anchor comprises threads; and the abutment comprises a nut configured to threadingly couple to the shaft of the anchor and thereby secure the abutment in a fixed orientation relative to the upper implant body. 
         [0025]    Clause 11. The dental implant system of clause 10, wherein the nut is captive within the abutment. 
         [0026]    Clause 12. The dental implant system of clause 1, wherein: the lower implant body comprises a first threaded portion; the upper implant body comprises a second threaded portion configured to be threadingly coupled to the first threaded portion; and the dental implant system further comprises a healing cover configured to be removably coupled to the first threaded portion. 
         [0027]    Clause 13. The dental implant system of clause 1, wherein the upper and lower implant bodies are configured to be welded together. 
         [0028]    Clause 14. The dental implant system of clause 1, further comprising an installation tool configured to be removably coupled to the upper implant body and apply a torque about the centerline of the lower implant body. 
         [0029]    Clause 15. The dental implant system of clause 14, wherein the installation tool is further configured to be removably coupled to the shaft of the anchor. 
         [0030]    Clause 16. The dental implant system of clause 1, further comprising an installation tool configured to be removably coupled to the abutment and apply a torque about the centerline of the lower implant body. 
         [0031]    Clause 17. A method of implanting a dental implant, the method comprising the steps of: implanting a dental implant system in a bone, the dental implant system comprising an externally threaded lower implant body configured to be implanted in bone, an upper implant body configured to couple to the lower implant body thereby forming a cavity between the upper and lower implant bodies, the upper implant body comprising an opening to the cavity, and a rotatable, swivelable anchor comprising a base disposed at least partially within the cavity, the base comprising a first substantially spherical surface, and a shaft coupled to the base and extending through the opening; and coupling an abutment to the shaft of the anchor. 
         [0032]    Clause 18. The method of clause 17, further comprising the steps of: coupling a healing cap to the abutment; allowing time for gum tissue adjacent to the bone to heal; and removing the healing cap. 
         [0033]    Clause 19. A method of implanting a dental implant, the method comprising the steps of: implanting a lower implant body through tissue into bone; placing an anchor in contact with the lower implant body, the anchor comprising a base that comprises a first substantially spherical surface and a shaft extending radially from the base; placing an upper implant body, having an opening, over the rotatable attachment such that the shaft extends through the hole; and coupling the upper implant body to the lower implant body. 
         [0034]    Clause 20. The method of clause 19, further comprising the steps of: coupling a healing cover to the lower implant body; allowing time for the bone to couple to the lower implant body; and removing the healing cover from the lower implant body. 
         [0035]    Clause 21. A dental implant system comprising: an externally threaded lower implant body configured to be implanted in bone and to sustain a torque of at least 20 Newton-centimeters (N·cm); an upper implant body configured to couple to the lower implant body, thereby forming a cavity between the upper and lower implant bodies, the upper implant body having an upper opening to the cavity; and a rotatable, swivelable attachment comprising: a substantially spherical member disposed within the cavity; and a shaft coupled to the substantially spherical member and extending from the member through the opening. 
         [0036]    Clause 22. The dental implant system of clause 21, wherein the externally threaded body is configured to sustain an insertion torque of at least 30 N·cm. 
         [0037]    Clause 23. The dental implant system of clause 22, wherein the externally threaded body is configured to sustain an insertion torque of at least 50 N·cm. 
         [0038]    Clause 24. The dental implant system of clause 21, further comprising an abutment configured to couple to the shaft of the rotatable attachment and to a prosthetic tooth. 
         [0039]    Clause 25. The dental implant system of clause 24, wherein the abutment comprises a captive nut configured to threadingly couple to the shaft of the rotatable attachment. 
         [0040]    Clause 26. A dental implant system comprising: a lower implant body configured to be implanted in bone; an upper implant body coupled to the lower implant body to form a cavity between the upper and lower implant bodies, the upper implant body having an opening to the cavity; a polyaxial sphere disposed within the cavity and having a radial bore; and an abutment configured to couple to a prosthetic tooth and having an internal passage; and an attachment element that passes through the passage, into the radial bore, and couples to the sphere, securing the abutment to the upper implant body. 
         [0041]    Clause 27. A method of implanting a dental implant, comprising: implanting a lower implant body in bone; placing a rotatable attachment, having a substantially spherical member and a shaft extending radially from the member, in contact with the lower implant body; placing an upper implant body, having an opening, over the rotatable attachment such that the shaft extends through the hole; and coupling the upper implant body to the lower implant body. 
         [0042]    Clause 28. The method of clause 27, further comprising coupling an abutment to the shaft, the abutment configured to attach to a prosthetic tooth. 
         [0043]    Clause 29. A method of implanting a dental implant, the method comprising the steps of: implanting a lower implant body in bone; placing a polyaxial sphere having a radial bore in contact with the lower implant body; placing an upper implant body, having an opening, over the polyaxial sphere; coupling the upper implant body to the lower implant body; and placing an abutment, having a passage therethrough, in contact with the upper implant body, the abutment configured to attach to a prosthetic tooth. 
         [0044]    Clause 30. The method of clause 29, further comprising passing an attachment element through the passage, through the opening, and into the bore; and coupling the attachment element to the polyaxial sphere. 
         [0045]    Clause 31. A dental implant system comprising: a lower implant configured to be implanted in bone, the lower implant comprising: an externally threaded body having a center axis, the body configured to sustain an insertion torque of at least 20 N·cm; and an internal ball coupled to the body; an upper implant coupled to the lower implant to form a cavity between the upper and lower implants, wherein the internal ball is disposed within the cavity, the upper implant having an opening to the cavity; a rotatable attachment comprising: a substantially spherical member disposed within the cavity between the upper and lower implants, the substantially spherical member comprising a shaped pocket configured to accept the internal ball, the internal ball and shaped pocket configured such that the internal ball has restricted rotation relative to the body about the center axis and can rotate relative to the body about axes perpendicular to the center axis; and a shaft coupled to, and extending from, the substantially spherical member through the opening. 
         [0046]    Clause 32. The dental implant system of clause 31, wherein the externally threaded body is configured to sustain an insertion torque of at least 30 N·cm. 
         [0047]    Clause 33. The dental implant system of clause 32, wherein the externally threaded body is configured to sustain an insertion torque of at least 50 N·cm. 
         [0048]    Clause 34. The dental implant system of clause 31, further comprising an abutment configured to couple to the shaft of the rotatable attachment. 
         [0049]    Clause 35. The dental implant system of clause 31, wherein: the lower implant and the upper implant are formed as a single unitary implant; and the opening to the cavity is formed in a configuration that allows the substantially spherical member of the rotatable attachment to be inserted through the opening into the cavity so as to engage the internal ball, after which the unitary implant is manipulated to modify the opening to a configuration that retains the substantially spherical member within the cavity. 
         [0050]    Clause 36. A dental implant system comprising: a body configured to be partially implanted in bone, the body comprising: a cavity comprising an internal surface, a portion of the internal surface being substantially spherical; and an opening through the body and within the substantially spherical portion of the internal surface, the opening having a perimeter; and an anchor comprising: a base comprising a substantially spherical external surface, the base disposed within the cavity with the substantially spherical external surface of the base in sealing contact with the substantially spherical internal surface of the cavity at least along the perimeter of the opening; and a shaft coupled to the base and extending from the base through the opening of the body. 
         [0051]    Clause 37. The dental implant system of clause 36, wherein: the body comprises a first anti-rotation feature with an axis; the first anti-rotation feature is disposed within the cavity of the body; and the base of the anchor comprises a second anti-rotation feature configured to cooperate with the first anti-rotation feature when the anchor is disposed within the cavity; the first and second anti-rotation features are configured to cooperatively resist rotation of the base relative to the body about the axis of the first anti rotation feature while allowing rotation of the base relative to the body about axes that are perpendicular to the axis of the first anti rotation feature. 
         [0052]    Clause 38. The dental implant system of clause 37, wherein: the first anti-rotation feature comprises a post; the second anti-rotation feature comprises an anti rotation cavity; at least a portion of the post is disposed within the anti rotation cavity. 
         [0053]    Clause 39. The dental implant system of clause 38, wherein: the post comprises a plurality of curved features arranged symmetrically about the axis; the anti-rotation cavity comprises a plurality of symmetrically arranged curved features; the curved features of the post are disposed within the curved features of the anti-rotation cavity. 
         [0054]    Clause 40. The dental implant system of clause 39, wherein the post and cavity each comprise six substantially cylindrical features arranged in a hexagonal configuration. 
         [0055]    Clause 41. The dental implant system of clause 36, wherein the body comprises: a lower body configured to be implanted in bone; and an upper body coupled to the lower body; wherein the upper body and lower body cooperate to form the cavity. 
         [0056]    Clause 42. A dental implant tool comprising: a body having a cavity at a proximal end, the cavity configured to engage a dental implant that comprises: a cavity comprising an internal surface, a portion of the internal surface being substantially spherical; and an opening through the body and within the substantially spherical portion of the internal surface, the opening having a perimeter; and an anchor comprising: a base comprising a substantially spherical external surface, the base disposed within the cavity with the substantially spherical external surface of the base in sealing contact with the substantially spherical internal surface of the cavity at least along the perimeter of the opening; and a shaft coupled to the base and extending from the base through the opening of the body. 
         [0057]    Clause 43. The dental implant tool of clause 42, wherein the body further comprises a torque feature at a distal end opposite the proximal end, the torque feature configured to engage a torque-applying tool. 
         [0058]    Clause 44. The dental implant tool of clause 42, further comprising an attachment element that passes through the body from the distal end toward the proximal end, the attachment element configured to engage the anchor of the dental implant. 
         [0059]    Clause 45. A dental implant tool comprising: a body having a cavity at a proximal end, the cavity configured to engage an abutment of a dental implant, the dental implant further comprising: a cavity comprising an internal surface, a portion of the internal surface being substantially spherical; and an opening through the body and within the substantially spherical portion of the internal surface, the opening having a perimeter; and an anchor comprising: a base comprising a substantially spherical external surface, the base disposed within the cavity with the substantially spherical external surface of the base in sealing contact with the substantially spherical internal surface of the cavity at least along the perimeter of the opening; and a shaft coupled to the base and extending from the base through the opening of the body. 
         [0060]    Clause 46. The dental implant tool of clause 45, further comprising an implant nut disposed within the abutment, the implant nut configured to engage the shaft of the anchor. 
         [0061]    Clause 47. A dental implant system comprising: a body configured to be partially implanted in bone, the body comprising: a cavity comprising an internal surface, a portion of the internal surface being substantially spherical; and an opening through the body and within the substantially spherical portion of the internal surface, the opening having a perimeter; and an anchor comprising: a base comprising a substantially spherical external surface, the base disposed within the cavity with the substantially spherical external surface of the base in sealing contact with the substantially spherical internal surface of the cavity at least along the perimeter of the opening; and a shaft coupled to the base and extending from the base through the opening of the body; an abutment comprising a generally cylindrical cavity with a bottom and a side wall, the bottom comprising an external surface having a portion that is substantially spherical, the abutment further comprising a hole through the bottom that is configured to fit over the portion of anchor shaft that extends through the opening in the body; and a nut disposed within the cavity of the abutment and configured to engage at least a portion of the anchor shaft that extends through the opening in the body. 
         [0062]    Clause 48. The dental implant system of clause 47, further comprising a healing cap configured to snap onto an abutment and ride against the top of the abutment. 
         [0063]    Clause 49. The dental implant system of clause 47, wherein the anchor further comprises an anti-rotation feature configured to cooperate with a mating feature of the base to resist rotation of the anchor about a center axis of the base. 
         [0064]    Clause 50. A method of providing a replacement tooth to a patient, the method comprising the step of: implanting a positionable dental implant into a jaw bone of the patient in an approximate surface location of the tooth that is being replaced, wherein the positionable dental implant comprises a base and an abutment, wherein the base comprises a positionable anchor comprising an anti-rotation feature that cooperates with a mating feature of the base to resist rotation of the anchor about a center axis of the base and a shaft that projects through a hole in the base, and wherein the abutment is releasably secured to the shaft of the anchor. 
         [0065]    Clause 51. The method of clause 49, further comprising the step of: securing a healing cap over the abutment with an interior surface of the healing cap in contact with a top surface of the abutment. 
         [0066]    Clause 52. The method of clause 49, wherein the step of implanting the positionable dental implant comprises the step of: implanting the base into the jaw bone at an angle to a center axis of the tooth that is being replaced so the base is in contact with a strongest portion of the jaw bone that is within the reach of the implant from the surface location of the tooth that is being replaced. 
         [0067]    Clause 53. The method of clause 50, wherein the step of implanting the positionable dental implant further comprises the step of: adjusting the position of the abutment so that a central axis of the abutment is generally parallel to the center axis of the tooth that is being replaced. 
         [0068]    Clause 54. The method of clause 51, wherein the step of adjusting the position of the abutment comprises the steps of: loosening a nut that is disposed within a cavity of the abutment and configured to engage the shaft of the positionable anchor thereby securing the abutment to the base; repositioning the anchor so that the central axis of the abutment is generally parallel to the center axis of the tooth that is being replaced; and tightening the nut. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0069]    The accompanying drawings, which are included to provide further understanding and are incorporated in and constitute a part of this specification, illustrate disclosed embodiments and together with the description serve to explain the principles of the disclosed embodiments. In the drawings: 
           [0070]      FIG. 1  is a cut-way illustration of an example of an existing dental implant. 
           [0071]      FIG. 2  is a cross-section of a natural tooth and a second example of an existing dental implant. 
           [0072]      FIG. 3A  illustrates a portion of the steps in a portion of an example existing implantation process. 
           [0073]      FIG. 3B  illustrates a crown being attached to a abutment  FIG. 1  in an example existing implantation process. 
           [0074]      FIGS. 4A and 4B  are perspective and cross-sectional views, respectively, of an exemplary positional dental implant according to certain aspects of this disclosure. 
           [0075]      FIGS. 5A and 5B  are perspective and cross-sectional views, respectively, of a portion of the positional dental implant of  FIGS. 4A and 4B  according to certain aspects of this disclosure. 
           [0076]      FIGS. 6A and 6B  are perspective and cross-sectional views, respectively of another exemplary positional dental implant according to certain aspects of this disclosure. 
           [0077]      FIG. 7  is a perspective view of a portion of the positionable dental implant of  FIGS. 6A and 6B  according to certain aspects of this disclosure. 
           [0078]      FIGS. 8A-8C  are cross-sections of stages in an exemplary implantation according to certain aspects of this disclosure. 
           [0079]      FIG. 8D  is a cross-section illustrating an alternate implantation configuration according to certain aspects of this disclosure. 
           [0080]      FIGS. 9A-9C  illustrate another embodiment of a positionable dental implant according to certain aspects of this disclosure. 
           [0081]      FIG. 10  depicts another embodiment of the implantable portion of a positionable dental implant according to certain aspects of this disclosure. 
           [0082]      FIG. 11  depicts the positionable dental implant of  FIG. 9A  implanted in a patient&#39;s jaw according to certain aspects of this disclosure. 
           [0083]      FIGS. 12A-12C  depict another embodiment of a positionable dental implant according to certain aspects of this disclosure. 
           [0084]      FIGS. 13A-13B  depict details of the anchor of  FIGS. 12A-12C  according to certain aspects of this disclosure. 
           [0085]      FIGS. 14A-14B  depict details of the lower implant of  FIGS. 12A-12C  according to certain aspects of this disclosure. 
           [0086]      FIGS. 15A-15B  depict perspective and cross-section views, respectively, of a T 1  tool according to certain aspects of this disclosure. 
           [0087]      FIGS. 16A-16B  depict perspective and cross-section views, respectively, of a T 2  tool according to certain aspects of this disclosure. 
           [0088]      FIGS. 17A-17B  depict perspective and cross-section views, respectively, of a T 3  tool according to certain aspects of this disclosure. 
           [0089]      FIGS. 18A-18B  depict perspective and cross-section views, respectively, of a T 4  tool according to certain aspects of this disclosure. 
           [0090]      FIGS. 19A-19B  depict perspective and cross-section views, respectively, of a T 5  tool according to certain aspects of this disclosure. 
           [0091]      FIGS. 20A-20B  depict perspective and cross-section views, respectively, of a healing cap according to certain aspects of this disclosure. 
           [0092]      FIGS. 21A-21B  depict perspective and cross-section views, respectively, of another embodiment of a positionable dental implant according to certain aspects of this disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0093]    The following description discloses embodiments of a positionable dental implant and method of implantation. 
         [0094]    In the following detailed description, numerous specific details are set forth to provide a full understanding of the present disclosure. It will be apparent, however, to one ordinarily skilled in the art that embodiments of the present disclosure may be practiced without some of the specific details. In other instances, well-known structures and techniques have not been shown in detail so as not to obscure the disclosure. 
         [0095]    The method and system disclosed herein are presented in terms of a dental implant used to replace a tooth for a human being. It will be apparent to those of ordinary skill in the art that these systems and methods may be applied in other applications such as veterinary medicine. Nothing in this disclosure, unless specifically stated, should be interpreted as limiting the disclosed systems and methods to the specific examples used herein. 
         [0096]    Within this disclosure, the term “substantially spherical” refers to a two- or three-dimensional contour that does not necessarily imply a perfectly spherical shape. Rather, substantially spherical structures described herein may be substantially or partially spherical in shape, have substantially circular or elliptical cross-sections, and/or have openings, indentations, defects, or aberrations in shape without departing from the substance of the subject technology. 
         [0097]    Within this disclosure, the term “substantially spherical surface” means that the surface has a one of more portions that share a common substantially spherical contour. The surface may be continuous or have grooves or recesses such that portions of the surface share the contour but are not continuous. The term “substantially spherical surface” does not imply that the surface subtends all or any particular portion of a sphere. 
         [0098]    Within this disclosure, the term “substantially embedded” means that a portion of one item is embedded within a second item sufficient to fulfill an intended purpose. In some aspects, a majority of the first item may be embedded in the second item. In some aspects, for example attachment, only enough of the first object required to provide adequate attachment to the second item is embedded in the second item. In some aspects, a portion of the first item may protrude from the second item. 
         [0099]      FIG. 1  is a cut-way illustration of an example of an existing dental implant. The dental implant is shown in the position in which it would be implanted to replace the center tooth. 
         [0100]      FIG. 2  is a cross-section of a natural tooth and a second example of an existing dental implant. The natural tooth structure is shown on the left and an example existing dental implant is shown on the right. This example dental implant has a threaded implant body and a cylindrical abutment that is screwed into a threaded recess (not visible) on the top of in the implant body.  FIG. 2  also illustrates the position of the bone and gum around this example implant. 
         [0101]      FIG. 3A  illustrates a portion of the steps in a portion of an example existing implantation process. The first picture is the state of the patient after the healing period has elapsed after the implant body was placed in the jaw. The second picture illustrates removal of the gum tissue overlying the implant using a tool, and the third picture is the removal of the temporary healing screw. The fourth picture illustrates installation of an abutment using a tool, and the fifth picture illustrates an installed healing cap over the abutment and gums. 
         [0102]      FIG. 3B  illustrates a crown being attached to a abutment  FIG. 1  in an example existing implantation process. In this example, the abutment is a simple pin and the crown has a matching recess (not visible) which is bonded to the pin. 
         [0103]      FIGS. 4A and 4B  are perspective and cross-sectional views, respectively, of an exemplary positional dental implant according to certain aspects of this disclosure. The following features are identified in  FIGS. 4A ,  4 B,  5 A, and  5 B. 
         [0000]    
       
         
               
               
             
               
               
             
           
               
                   
               
               
                 Ref. identifier 
                 Feature 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 1 
                 Upper implant 
               
               
                 2 
                 Lower implant 
               
               
                 3 
                 Abutment 
               
               
                 4 
                 Abutment inclination angle (alpha) 
               
               
                 5 
                 Lower implant centerline 
               
               
                 6 
                 Abutment centerline 
               
               
                 7 
                 Abutment rotation angle (beta) 
               
               
                 8 
                 upper implant scarf 
               
               
                 9 
                 threaded installation feature 
               
               
                 10 
                 Thread-cutting groove 
               
               
                 11 
                 third substantially spherical surface 
               
               
                 13 
                 Abutment scarf 
               
               
                 14 
                 second substantially spherical surface 
               
               
                 15 
                 first substantially spherical surface 
               
               
                 16 
                 Attachment interface 
               
               
                 17 
                 Polyaxial sphere 
               
               
                 18 
                 Flexure 
               
               
                 19 
                 fourth substantially spherical surface 
               
               
                 22 
                 attachment stop surfaces 
               
               
                 24 
                 Hexagonal recess 
               
               
                 25 
                 Fastener 
               
               
                 26 
                 Keeper groove 
               
               
                 27 
                 Keeper 
               
               
                 29 
                 positionable dental implant 
               
               
                   
               
             
          
         
       
     
         [0104]    In certain embodiments, the lower implant body  2  is installed into the bone of a patient prior to assembly with the upper implant body  1 . An installation tool (not shown in  FIG. 4A ) may be removable coupled to the lower implant body  2  and manipulated such that the lower implant body is inserted through the gum tissue of a patient and into the jaw bone. In certain embodiments, this installation includes the rotation of the lower implant body about axis  5  such that the external threads of the lower implant body  2  engage the bone. In certain embodiments, a thread-cutting groove  10  assists in cutting threads into the bone to assist in the implantation. In certain embodiments, a torque is applied to the lower implant body  2  to rotate the lower implant body as it is implanted into the bone. In certain embodiments, the lower implant body  2  is configured to withstand an installation torque of up to 20 newton-centimeters (N·cm). In certain embodiments, the lower implant body  2  is configured to withstand an installation torque of up to 30 N·cm. In certain embodiments, the lower implant body  2  is configured to withstand an installation torque of up to 50 N·cm. 
         [0105]    In certain embodiments, the upper and lower implant bodies  1  and  2  are assembled prior to implantation of the lower implant body  2  into the bone of the patient. In certain embodiments, the upper and lower implant bodies  1  and  2  are coupled with threads. In certain embodiments, the upper implant body  1  is tightened onto the lower implant body  2  until the attachment stop surfaces  22  touch. 
         [0106]    When the upper implant body  1  is coupled to the lower implant body  2 , a flexure  18  is placed on the lower implant body  2 , then a polyaxial sphere  17  is placed on the flexure  18  and the upper implant body  1  placed over the polyaxial sphere  17  and coupled to the power implant body  2 . The flexure  18  applies a force to the polyaxial sphere  17  that places the first substantially spherical surface  15  in at least partial contact with the second substantially spherical surface  19 . In this embodiment, the polyaxial sphere  17  is free to rotate away the axis  5 , shown as an angle  4 , also referred to as the ‘alpha angle,’ and rotate about the axis  6 , also referred to as the ‘beta angle,’ which is also aligned with the attachment interface  16 . 
         [0107]      FIG. 4B  illustrates an exemplary embodiment wherein abutment  3  is attached to the polyaxial sphere  17  with a fastener  25 . In certain embodiments, the attachment  25  is a socket bolt having a hexagonal recess  24  that is used with a tool, such as a hex wrench (not shown in  FIG. 4B , to tighten the fastener  25  to the polyaxial sphere  17 . 
         [0108]      FIGS. 5A and 5B  are perspective and cross-sectional views, respectively, of a portion of the positional dental implant  29  of  FIGS. 4A and 4B  according to certain aspects of this disclosure. 
         [0109]      FIG. 5B  illustrates a threaded installation feature  9  used, in certain embodiments, to enable attachment of an installation tool to the lower implant body  2 . In certain embodiments, the attachment feature  16  is the same or larger than installation feature  9  such that a tool may pass through the attachment feature  16  to reach the installation feature  9  and thus allow installation of the assembled upper and lower implant bodies  1  and  2 . 
         [0110]      FIGS. 6A and 6B  are perspective and cross-sectional views, respectively of another exemplary positional dental implant  41  according to certain aspects of this disclosure. The upper implant  32  and the lower implant  30  are similar to the upper and lower implants  1 ,  2  of  FIGS. 4A and 4B . In this implant  41 , a positionable anchor  43  comprises a base  34  that is captured between the upper and lower implants  32 ,  30  and a shaft  42  that is coupled to the base  34  and extends along a radial axis from the base  34 . The anchor  43  is able to rotate and turn over a conical region defined by the movement of the shaft  42  within an opening  38  of the upper implant  32 . In certain embodiments, the abutment  36  comprises a threaded bore  40  and the shaft  42  has a matching set of threads such that the abutment  36  may be screwed onto the threaded shaft  42 . The angular position of the anchor  43  becomes fixed when the abutment  36  is tightened onto shaft  42 . 
         [0111]      FIG. 7  is a perspective view of a portion of the positional dental implant of  FIGS. 6A and 6B  according to certain aspects of this disclosure. It can be seen how the shaft  42  can rotated as limited by the opening  38  of the upper implant  32 . 
         [0112]      FIGS. 8A-8C  are cross-sections of stages in an exemplary implantation process according to certain aspects of this disclosure.  FIG. 8A  shows the lower implant  30  placed through the gum tissue  62  and into the jaw bone  60  of a patient. In this embodiment, the lower implant  30  is oriented vertically under the location of the tooth to be replaced. It can be seen that, in this embodiment, the top of the lower implant  30  is recessed from the surface of the bone  60 . In certain embodiments, the top of the lower implant  30  is flush with the surface of the bone  60 . A healing cover  50  has been placed over the lower implant  30 . In certain embodiments, the lower implant  30  comprises a first threaded portion and the healing cover  50  is configured to be removably coupled to the first threaded portion of the lower implant  32 . In certain embodiments, the gum  62  is sutured over the healing cover  50 . 
         [0113]    In  FIG. 8B , some gum tissue  62  and the healing cover  50  have been removed and an anchor  34  and upper implant  32  installed. The anchor is rotated to provide the desired angle of the tooth crown (not shown in  FIG. 8B ) that is to be attached. A healing cap  52  is installed over the threaded shaft  42 . In certain embodiments, the step shown in  FIG. 8B  is omitted. 
         [0114]    In  FIG. 8C , the healing cap  52  has been removed and an abutment  36  has been coupled to the shaft  42 . The lower spherical interface of the abutment  36 , corresponding to the fourth substantially spherical surface  19  of the abutment  3  of  FIG. 4B , mates with the top spherical surface of the upper implant  32 , corresponding to the third substantially spherical surface  11  of the upper implant body  1  of  FIG. 4B . 
         [0115]      FIG. 8D  is a cross-section illustrating another embodiment of an implantation configuration according to certain aspects of this disclosure. In this embodiment, the lower implant  30  has been implanted at an angle to a vertical axis  70  located under the location of the tooth to be replaced. This allows the lower implant  30  to be placed, for example, into a region of the jaw where the bone  60  is denser. It can be seen that the rotational capability of the anchor  34  relative to the lower implant  30  allows the abutment  36  to be placed in the same position as in  FIG. 8C  despite the difference in the position of the lower implant  30 . 
         [0116]      FIGS. 9A-9C  illustrate another embodiment  100  of a positionable dental implant according to certain aspects of this disclosure. The following elements are identified in  FIGS. 9A-9C . 
         [0000]    
       
         
               
               
             
               
               
             
           
               
                   
               
               
                 ref. identifier 
                 Feature 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 5 
                 axis of the lower implant body 
               
               
                 6 
                 axis of the abutment 
               
               
                 38 
                 Implant thread form 
               
               
                 39 
                 Reduced area of abutment 
               
               
                 41 
                 portion of upper implant body wherein the surface 
               
               
                   
                 is abraded for osteoblast 
               
               
                 42 
                 Abutment 
               
               
                 43 
                 Captive nut 
               
               
                 44 
                 Anchor 
               
               
                 45 
                 upper implant scarf 
               
               
                 46 
                 Implant assembly (includes 44, 47, 49) 
               
               
                 47 
                 Lower implant body 
               
               
                 48 
                 shaft 
               
               
                 49 
                 Upper implant body 
               
               
                 50 
                 first substantially spherical surface 
               
               
                 51 
                 Flexure 
               
               
                 52 
                 abutment scarf 
               
               
                 53 
                 retaining clip 
               
               
                 54 
                 hexagonal recess 
               
               
                 55 
                 groove 
               
               
                 56 
                 second substantially spherical surface 
               
               
                 100 
                 dental implant 
               
               
                   
               
             
          
         
       
     
         [0117]    In this embodiment, the abutment  42  comprises a captive locking nut  43  that is captured by a retaining clip  53  that engages a groove  55  formed in the abutment  42 . In certain embodiments, the nut  43  comprises a hexagonal recess  54  that allows use of a tool (not shown) to tighten the nut  43  onto the shaft  44 . Flexure  51  provides constant contact pressure between the first substantially spherical surface  50  of anchor  43  and the second substantially spherical surface  56 . 
         [0118]      FIG. 10  depicts another embodiment of the implantable portion of a positionable dental implant  100  according to certain aspects of this disclosure. The following elements are identified in  FIG. 10  in addition to elements previously identified.
         60  Non-rotating anchor     62  anti-rotation cavity     64  Hex ball     66  anti-rotation post     68  Non-rotating lower implant body     70  Hex cavity     72  axis of anti-rotation post       
 
         [0126]    The anti-rotation post  66  comprises a hex ball  64  fits into the anti-rotation cavity  62  in the non-rotating anchor  60  such that the anchor  60  cannot rotate relative to the lower implant  68  about the axis  72  but can rotate about axes perpendicular to axis  72 . In certain embodiments, the axis  72  is coincident with the centerline  37  of the lower implant body  68 . The hex ball shaft  66  has a straight hex profile that matches the hex cavity  70  of lower implant  68  such that the anti-rotation post  66  cannot rotate relative to the lower implant body  68 . 
         [0127]    In certain embodiments, the hex ball  64  and anti-rotation cavity  62  each have six facets configured to engage each other. In certain embodiments, the facets of the hex ball  64  are curved about an axis perpendicular to axis  72 . In certain embodiments, the hex ball  64  and anti-rotation cavity  62  have a common number of facets that is different from six. 
         [0128]      FIG. 11  depicts the positionable dental implant  100  of  FIG. 9A  implanted in a patient&#39;s jaw according to certain aspects of this disclosure. The upper portion  36 A of the abutment  36  is configured to accept a crown  74 . In certain embodiments, portion  36 B is configured to be substantially embedded in the tissue  62  of the patient. In certain other embodiments, the implant assembly  46  is implanted at a greater depth, while in certain other embodiments, the implant assembly  46  is implanted at a lesser depth. In certain embodiments, the implant assembly  46  is implanted with the alpha axis  37  at an angle to the vertical (as seen in  FIG. 11 ) similar to  FIG. 8D . In certain embodiments, the elements of  FIG. 10  replace the like elements of  FIGS. 9A-9B . 
         [0129]      FIGS. 12A-12C  depict another embodiment  101  of a positionable dental implant according to certain aspects of this disclosure.  FIG. 12A  depicts an external view of the assembled dental implant  101  with a section line B-B. 
         [0130]      FIG. 12B  is a cross-section along the section line B-B of  FIG. 12A . Dental implant  101  includes a lower implant  105  having a body  106  and an anti-rotation post  107 , an upper implant  110 , and a positionable anchor  120  having a threaded shaft  122  and a base  126  with an anti-rotation cavity  124 . In this embodiment, the upper implant  110  is electron-beam welded to the lower implant  105  prior to implantation in the patient&#39;s jaw. The area indicated by the broken-line circle labeled ‘ 12 C’ is enlarged in  FIG. 12C . 
         [0131]      FIG. 12C  is an enlarged portion of  FIG. 12B  wherein the anchor  120  includes a base  126  having a spherical interface surface  127 . Upper implant  110  has an internal interface  111  that is substantially spherical. When assembled, and after an abutment (not shown) is tightened onto the threaded body  122 , the spherical interface surface  127  of the anchor  120  is in contact with the spherical interface surface  111  of the upper implant  110 . This contact between surfaces  127  and  11  forms a continuous seal along a perimeter  130  around the edge of the opening  112  in the upper implant  110 . This continuous seal resists debris and bacteria from entering the internal volume  140  formed within dental implant  100 . Accumulation of debris, such as liquid or solid food, in a recess where bacteria can multiple and not be easily removed in normal oral care creates a risk of infection for the patient. Providing a continuous seal along perimeter  130  reduces this risk. 
         [0132]      FIGS. 13A-13B  depict details of the anchor of  FIGS. 12A-12C  according to certain aspects of this disclosure.  FIG. 13A  is a cross-section of the anchor  120  showing the anti-rotation cavity  124 .  FIG. 13B  is an end view from the anti-rotation cavity  124  in which it can be seen that, in this embodiment, the cavity  124  has a hexagonal profile. 
         [0133]      FIGS. 14A-14B  depict details of the lower implant of  FIGS. 12A-12C  according to certain aspects of this disclosure.  FIG. 14A  is a cross-section of a portion of the lower implant  105  showing the anti-rotation post  107 .  FIG. 14B  is an end view from the anti-rotation post  107  in which it can be seen that, in this embodiment, the post  107  has a hexagonal profile. In certain aspects, the dimensions of the post  107  and the cavity  124  are selected such that the post  107  has clearance within the cavity  124 . In certain aspects, the post  107  and cavity  124  are fabricated such that there is effectively zero clearance, i.e. less than 0.001 inches, between the two when assembled. 
         [0134]    When the dental implant  100  is assembled as shown in  FIGS. 12A-12B , the hexagonal features of this embodiment of the post  107  are disposed within the hexagonal features of the this embodiment of the cavity  127 . In this configuration, the anchor  120  is free to tilt with respect to the upper and lower implant  110 ,  105 , i.e. rotate about axes that are perpendicular to the axis  101  shown in  FIG. 12B . The hexagonal features of post  107  cooperate with the hexagonal features of the cavity  127  to resist rotation of anchor  120  relative to the upper and lower implant  110 ,  105  about the axis  101 . In certain embodiments, the maximum dimension of an aspect the post  107 , such as the width of the flats across the hexagon, and the minimum dimension of the corresponding aspect of the cavity  127  are selected to be identical to minimize the clearance between the post  107  and cavity  127 . 
         [0135]      FIGS. 15A-15B  depict perspective and cross-section views, respectively, of a T 1  insertion tool  150  according to certain aspects of this disclosure. The tool  150  is adapted for installation of a dental implant  100 , or similar, when the abutment  42  is not attached. The tool  150  comprises an outer tube  152  that is configured to engage the outer surface of the upper implant  49  and an inner shaft  154  that is configured to engage the shaft  48  of the anchor  44 . Tightening the upper knob  155  pulls the anchor  44  upward against the inner surface  56  of the upper implant body  49  thereby locking the orientation of the tool  150  with respect to the lower implant body  47 . Torque can then be applied to the flats  156  of the tool  150  to implant the lower implant  47  into the jawbone. 
         [0136]      FIGS. 16A-16B  depict perspective and cross-section views, respectively, of a T 2  insertion tool  160  according to certain aspects of this disclosure. The tool  160  adapted for installation when the abutment  42  is not attached. The tool  160  comprises a shaft  162  having a first cavity that is configured to engage the upper implant body  49  and the upper implant scarf  45  such that the tool  160  can apply torque to the implant  100 . In certain aspects, the implant  100  is free to fall out of the cavity  164 . In certain aspects, a retention feature (not shown in  FIG. 16A  or  16 B), for example an o-ring partially embedded in a wall of the cavity  164 , provides retention force to retain the implant  100  within the cavity  164 . A second cavity  166  provides space for the shaft  44  but does not engage the shaft  44 . 
         [0137]      FIGS. 17A-17B  depict perspective and cross-section views, respectively, of a T 3  insertion tool  170  according to certain aspects of this disclosure. The tool  170  is adapted to engage the implant  100  in a manner similar to tool  160 . Tool  170  comprises a series of torquing flats  176  and a retention feature  174 , in this example an o-ring, to prevent the tool  170  from falling out of the device (not shown) applying torque to the torquing flats  176 . 
         [0138]      FIGS. 18A-18B  depict perspective and cross-section views, respectively, of a T 4  tool  180  according to certain aspects of this disclosure. The tool  180  is adapted for installation when the abutment  42  is attached and the captive nut  43  tightened. The tool  180  comprises a shaft  182  and a cavity  184  configured to engage the outside surface of the abutment  42  and the abutment scarf  52 . In certain aspects, the implant  100  is free to fall out of the cavity  184 . 
         [0139]      FIGS. 19A-19B  depict perspective and cross-section views, respectively, of a T 5  tool  190  according to certain aspects of this disclosure. The tool  190  is adapted to engage the implant  100  in a manner similar to tool  180 . Tool  190  comprises a series of torquing flats  196  and a retention feature  194 , in this example an o-ring, to prevent the tool  190  from falling out of the device (not shown) applying torque to the torquing flats  196 . 
         [0140]      FIGS. 20A-20B  depict perspective and cross-section views, respectively, of a healing cap  200  according to certain aspects of this disclosure. The cap  200  snaps onto an abutment  42  and rides against the top of the abutment  42 . In certain embodiments, the cap  200  comprises a clip edge  202  configured to engage the ridge of the abutment  42 . 
         [0141]      FIGS. 21A-21B  depict perspective and cross-section views, respectively, of another embodiment of a positionable dental implant  210  according to certain aspects of this disclosure. In this embodiment, a upper implant body  212  and lower implant body  214  are configured similar to the upper and lower implant bodies  47  and  439  of implant  100 , shown in  FIG. 9A , except that upper and lower implant bodies  212  and  214  are welded along the seam  216 . In certain aspects, the upper and lower implant bodies  212  and  214  are e-beam welded. In certain aspects, the upper and lower implant bodies  212  and  214  are continuously welded. In certain aspects, the upper and lower implant bodies  212  and  214  are intermittently welded. 
         [0142]    The concepts disclosed herein provide a system and method for implantation of an implant body at an angle from a vertical axis under the location of a tooth to be replaced. The angular installation allows the implant body to be placed so as to improve the strength and healing of the dental implant in the jaw bone while retaining the ability to position the abutment, and therefore the crown, in the natural tooth orientation. 
         [0143]    The previous description is provided to enable a person of ordinary skill in the art to practice the various aspects described herein. While the foregoing has described what are considered to be the best mode and/or other examples, it is understood that various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but is to be accorded the full scope consistent with the language claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more.” Unless specifically stated otherwise, the terms “a set” and “some” refer to one or more. Pronouns in the masculine (e.g., his) include the feminine and neuter gender (e.g., her and its) and vice versa. Headings and subheadings, if any, are used for convenience only and do not limit the invention. 
         [0144]    It is understood that the specific order or hierarchy of steps in the processes disclosed is an illustration of exemplary approaches. Based upon design preferences, it is understood that the specific order or hierarchy of steps in the processes may be rearranged. Some of the steps may be performed simultaneously. The accompanying method claims present elements of the various steps in a sample order, and are not meant to be limited to the specific order or hierarchy presented. 
         [0145]    Terms such as “top,” “bottom,” “front,” “rear” and the like as used in this disclosure should be understood as referring to an arbitrary frame of reference, rather than to the ordinary gravitational frame of reference. Thus, a top surface, a bottom surface, a front surface, and a rear surface may extend upwardly, downwardly, diagonally, or horizontally in a gravitational frame of reference. 
         [0146]    A phrase such as an “aspect” does not imply that such aspect is essential to the subject technology or that such aspect applies to all configurations of the subject technology. A disclosure relating to an aspect may apply to all configurations, or one or more configurations. A phrase such as an aspect may refer to one or more aspects and vice versa. A phrase such as an “embodiment” does not imply that such embodiment is essential to the subject technology or that such embodiment applies to all configurations of the subject technology. A disclosure relating to an embodiment may apply to all embodiments, or one or more embodiments. A phrase such an embodiment may refer to one or more embodiments and vice versa. 
         [0147]    The word “exemplary” is used herein to mean “serving as an example or illustration.” Any aspect or design described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects or designs. 
         [0148]    All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. No claim element is to be construed under the provisions of 35 U.S.C. §112, sixth paragraph, unless the element is expressly recited using the phrase “means for” or, in the case of a method claim, the element is recited using the phrase “step for.” Furthermore, to the extent that the term “include,” “have,” or the like is used in the description or the claims, such term is intended to be inclusive in a manner similar to the term “comprise” as “comprise” is interpreted when employed as a transitional word in a claim.