Patent Publication Number: US-2005136380-A1

Title: Endosseous dental implant

Description:
This invention relates to endosseous dental implants comprising an, at least partly, externally-threaded body portion, and in some embodiments, an unthreaded external top portion. These implants also comprise an internal cavity or shaft with an opening to the cavity or shaft at the top surface of the implant. This internal cavity or shaft comprises a threaded portion, which begins in the internal cavity or shaft below the top surface of the implant, and ends in the internal cavity or shaft, inside the body portion. The body portion may be cylindrical, conical, or tapered, and may include external, self-tapping threads on the body portion.  
      The internal cavity or shaft includes a wrench-engaging surface that, in preferred embodiments, comprises surfaces forming three points or apexes or slots equally spaced from one another by 120 degrees, representing the points of a triangle, or, alternatively, three alternate points of an equal sided hexagon. The three-pointed/slotted wrench-engaging surfaces start at or below the top surface and extend into the internal cavity or shaft. The wrench-engaging surfaces are adapted to receive and engage a complementary insertion tool for insertion of the implant into an opening or bore formed in the jawbone of a patient.  
      The internal cavity or shaft also comprises multi-lobed, preferably three-lobed, surfaces, formed in the internal cavity or shaft. The preferred three lobes of this abutment-engaging surface are positioned between the three points or apexes of the wrench-engaging surface. The preferred tri-lobed surfaces can be formed above, below or in substantially the same plane, or area, as the wrench-engaging surfaces.  
      In preferred embodiments, the wrench-engaging surfaces have their three points/sides/slots in an area that is smaller than, larger than or substantially the same size as the area in which the three lobes are located. In such preferred embodiments, the internally-threaded portion of the internal cavity or shaft lies below the wrench-engaging surfaces and the tri-lobed surfaces.  
      The threaded portion of the internal cavity of the implant may be substantially the same in cross-sectional area as the internal wrench-engaging surfaces, or may be smaller in cross-section than either the wrench-engaging or tri-lobed surfaces.  
      The opening to the internal cavity or shaft of the implant may be chamfered or beveled, preferably all around the opening. The chamfered or beveled portion is, in some embodiments, of sufficient size and shape to receive and engage any abutment, adapter or other connector inserted into the opening. When the opening to the internal cavity or shaft is chamfered/beveled, a complementary adapter, connector or abutment can, in some embodiments, form a smooth, easily cleaned margin between the implant and the abutment, adapter, or connector.  
      The internal cavity or shaft of the dental implant is, in preferred embodiments, complementary in size and shape to abutments, adapters or other connectors, especially two-part abutments, adapters or other connectors. The abutment may be a dental component such as a healing cap, or impression post, or a temporary or more permanent abutment. In preferred embodiments, such abutments engage the tri-lobed surfaces, may also engage the three-pointed wrench-engaging surfaces, and may have an inner bore that extends through the center of the abutment, with a flange or seat formed in this inner bore. Such a flange or seat supports a threaded screw which fits into and through the inner bore of the abutment, and extends beyond the inner bore for engagement with the internal threads of an implant. In preferred embodiments, these implants have a length in the range of about 8 mm to about 20 mm, and an outer diameter in the range of about 3 mm to about 7 mm. The internal cavity or shaft preferably has a length in the range of about 4 mm to about 8 mm, and a cross-section (or plurality of cross-sections) in the range of about 1.5 mm to about 3.5 mm.  
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The present invention can better be understood from the following detailed description of a preferred embodiment of the invention, taken in conjunction with the accompanying drawings, in which like reference symbols refer to like parts, and in which:  
       FIG. 1  is a perspective view of a preferred embodiment of the endosseous dental implant;  
       FIG. 2  is a cross-sectional view of the implant shown in  FIG. 1 , taken on line  2 - 2  of  FIG. 1 ;  
       FIG. 3  is a top plan view of the implant shown in  FIGS. 1 and 2 ;  
       FIG. 4  is a perspective view of a second preferred embodiment of the endosseous dental implant;  
       FIG. 5  is a cross-sectional view of the implant shown in  FIG. 4 , taken on line  2 - 2  of  FIG. 4   
       FIG. 6  is a top plan view of the implant shown in  FIGS. 4 and 5 ;  
       FIG. 7  is a perspective view of a third preferred embodiment of the endosseous dental implant;  
       FIG. 8  is a cross-sectional view of the implant shown in  FIG. 7 , taken on line  2 - 2  of  FIG. 7 ;  
       FIG. 9  is a top plan view of the implant shown in  FIGS. 7 and 8 ;  
       FIG. 10  is a perspective view of a fourth preferred embodiment of the endosseous dental implant;  
       FIG. 11  is a cross-sectional view of the implant shown in  FIG. 10 , taken on line  2 - 2  of  FIG. 10 ;  
       FIG. 12  is a top plan view of the implant shown in  FIGS. 10 and 11 .  
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       FIG. 1  shows endosseous dental implant  10  with external threading  11  over more than half the length of the external surface of implant  10 , and with upper unthreaded external body portion  12 . Together, external body portions  11  and  12  comprise the entire external body portion of implant  10 . At the top of implant  10  is top surface  23 . Below top surface  23  and internal to implant  10  is internal cavity or shaft  22 . Opening  13  in top surface  23  of implant  10  leads inwardly and downwardly to internal cavity or shaft  22 . Cavity  22  includes (See  FIG. 2 ) threaded portion  20 , and, below portion  20 , unthreaded portion  21 . Threaded portion  21  terminates in passage  22  inside implant  10 .  
      Starting at and extending below top surface  23  are internal wrench-engaging surfaces  14 ,  15 , and  16 , which comprise three apexes of an internal triangle formed in passage  22 . These apexes  14 ,  15 , and  16  are adapted to receive and engage a three-sided or other wrench-engaging tool for insertion of implant  10  into an opening or bore formed in the jawbone of a patient by threading or screwing implant  10  into such an opening or bore.  
      Starting at and extending below top surface  23 , and internal to implant  10  are tri-lobed surfaces  17 ,  18 , and  19 , which are formed in substantially the same plane (or substantially above or below the plane) within which apexes  14 ,  15 , and  16  lie. This tri-lobed surface has rounded surfaces which lie within an area that is substantially greater or smaller in size than the area within which apexes  14 ,  15 , and  16  lie, and/or than the area occupied by the internally threaded portion  20 . The tri-lobed surfaces  17 ,  18 , and  19  are adapted to receive and engage an abutment, and may be denoted as abutment-engaging or adapter-engaging surfaces. The external threading  11  on the external surface of implant  10  may be a multiple-lead thread, e.g. a double or triple lead thread, as described in U.S. Pat. No. 5,591,029, columns  14  and  15 , or a combination of single and multiple lead threads. The text and drawings of the &#39;029 patent are hereby incorporated by reference in full as though fully set forth here, as are the text and drawings of U.S. Pat. No. 4,960,381, issued Oct. 2, 1990, entitled “Screw-Type Dental Implant Anchor”. The &#39;029 patent is entitled “Dental Implant System”, issued Jan. 7, 1997, and reissued as RE  37 , 646  on Apr. 9, 2002.  
       FIG. 4  shows endosseous dental implant  110  with external threading  111  over more than half the length of the external surface of implant  110 , and with upper unthreaded external body portion  112 . Together, external body portions  111  and  112  comprise the entire external body portion of implant  110 . At the top of implant  110  is top surface  123 . Below top surface  123  and internal to implant  110  is internal cavity or shaft  122 . Opening  113  in top surface  123  of implant  110  leads inwardly and downwardly to internal cavity or shaft  122 . At the edge of opening  113  is bevel/chamfer  130 , which extends all around opening  113 , but could extend only partly around opening  113 . Cavity  122  includes (See  FIG. 2 ) threaded portion  120 , and, below portion  120 , unthreaded portion  121 . Threaded portion  121  terminates in passage  122  inside implant  110 .  
      Substantially entirely below top surface  123  are internal wrench-engaging surfaces  114 ,  115 , and  116 , which comprise three apexes of an internal triangle formed in passage  122 . These apexes  114 ,  115 , and  116  are adapted to receive and engage a three-sided or other wrench-engaging tool for insertion of implant  110  into an opening or bore formed in the jawbone of a patient by threading or screwing implant  110  into such an opening or bore.  
      Also internal to implant  110  are tri-lobed surfaces  117 ,  118 , and  119 , which are formed in substantially the same plane (or substantially above or below the plane) within which apexes  114 ,  115 , and  116  lie. These tri-lobed surfaces have rounded surfaces which lie within an area that is substantially greater than or smaller than the area within which apexes  114 ,  115 , and  116  lie, and/or than the area occupied by the internally threaded portion  120 . The tri-lobed surfaces  117 ,  118 , and  119 , and non-circular bevel/chamfer  130 , are adapted to receive and engage an abutment, and may therefore be denoted abutment-engaging or adapter-engaging surfaces. The external threading  111  on the external surface of implant  110  may be a single or, alternately a multiple-lead thread, e.g. a double or triple lead thread, as described in U.S. Pat. No. 5,591,029, columns  14  and  15 , or a combination of single and multiple lead threads.  
       FIG. 7  shows endosseous dental implant  210  with external threading  211  over more than half the length of the external surface of implant  210 , and with upper unthreaded external body portion  212 . Together, external body portions  211  and  212  comprise the entire external body portion of implant  210 . At the top of implant  210  is top surface  223 . Below top surface  223  and internal to implant  210  is internal cavity or shaft  222 . Opening  213  in top surface  223  of implant  210  leads inwardly and downwardly to internal cavity or shaft  222 . Cavity  222  includes (See  FIG. 2 ) threaded portion  220 , and, below portion  220 , unthreaded portion  221 . Threaded portion  221  terminates in passage  222  inside implant  210 .  
      Starting at and extending below top surface  223  are internal wrench-engaging surfaces  240 - 246 . These surfaces include sides  240 ,  241 ,  242 ,  243 ,  244 ,  245 , and  246 , and the corresponding points formed by these sides, form a multi-pointed wrench-engaging surface, and are adapted to receive and engage alternate points of a hex-shaped or other wrench-engaging tool for insertion of implant  210  into an opening or bore formed in the jawbone of a patient by threading or screwing implant  210  into such an opening or bore.  
      Also internal to implant  210  are tri-lobed surfaces  217 ,  218 , and  219 , which are formed in substantially the same plane (or substantially above or below the plane) within which sides  240 - 246  lie. These tri-lobed surfaces have rounded surfaces which lie within an area that is substantially greater than or smaller than the area within which sides  240  to  246  lie, and/or than the area occupied by the internally threaded portion  220 . Tri-lobed surfaces  217 ,  218 , and  219  are adapted to receive and engage an abutment, and may therefore be denoted abutment-engaging or adapter-engaging surfaces. The external threading  211  on the external surface of implant  210  may be a multiple-lead thread, e.g. a double or triple lead thread, as described in U.S. Pat. No. 5,591,029, columns  14  and  15 , or a combination of single or multiple lead threads.  
       FIG. 10  shows endosseous dental implant  310  with external threading  311  over more than half the length of the external surface of implant  310 , and with upper unthreaded external body portion  312 . Together, external body portions  311  and  312  comprise the entire external body portion of implant  310 . At the top of implant  310  is top surface  323 . Below top surface  323  and internal to implant  310  is internal cavity or shaft  322 . Opening  313  in top surface  323  of implant  310  leads inwardly and downwardly to internal cavity or shaft  322 . At the edge of opening  313  is bevel/chamfer  330 , which extends all around opening  313 , but could extend only partly around opening  313 . Cavity  322  includes (See  FIG. 2 ) threaded portion  320 , and, below portion  320 , unthreaded portion  321 . Threaded portion  321  terminates in passage  322  inside implant  310 .  
      Substantially entirely below top surface  323  are internal wrench-engaging surfaces  340 - 346 . These surfaces include sides  340 ,  341 ,  342 ,  343 ,  344 ,  345 , and  346 , and the points formed by these sides, form a multi-pointed wrench-engaging surface, and are adapted to receive and engage alternate points of a hex-shaped or other wrench-engaging tool for insertion of implant  310  into an opening or bore formed in the jawbone of a patient by threading or screwing implant  310  into such an opening or bore.  
      Also internal to implant  310  are tri-lobed abutment-engaging surfaces  317 ,  318 , and  319 , which are formed in substantially the same plane (or substantially above or below the plane) within which sides  340 - 346  lie. These tri-lobed surfaces have rounded surfaces which lie within an area that is substantially greater than or smaller than the area within which sides  340 - 346  lie, and/or than the area occupied by the internally threaded portion  320 . Tri-lobed surfaces  317 ,  318 , and  319 , and bevel/chamfer  330 , are adapted to receive and engage an abutment, and may therefore be denoted abutment-engaging or adapter-engaging surfaces. The external threading  311  on the external surface of implant  310  may be a multiple-lead thread, e.g. a double or triple lead thread, as described in U.S. Pat. No. 5,591,029, columns  14  and  15 , or a combination of single lead and multiple-lead threads.  
      One advantage of the multi-pointed/slotted wrench-engaging surfaces is that an insertion tool can, in preferred embodiments, fit frictionally into the points or apexes or slots of the wrench-engaging surfaces, permitting a dental professional to carry and insert the implant properly and precisely in an opening or bore formed in the jawbone of a patient.  
      One advantage of the tri-lobed surfaces is that a dental professional has good tactile sense to assure full seating when inserting an abutment, adapter or connector into this surface. Furthermore, the mating, rounded surfaces of the tri-lobed abutment connection provide adequate material thickness to withstand rotational and tipping forces during mastication.  
      One advantage of the non-circular bevel all around, or partly around, the opening to the internal shaft, where present, is to help center the abutment, thus facilitating initial alignment of the tri-lobed surfaces. Another advantage is to provide for engagement of a mating, beveled surface on the abutment, preventing rotational movement of the abutment when fully seated in the implant and held in place by a fixation screw.