Dental implant system

Abstract

A dental implant assembly is provided, as well as a system and method for exposing an embedded implant after osseointegration has taken place. The implant assembly comprises an implant member for embedding in the jaw and a rest factor member for securing to the implant member, the rest factor member having an upper rest surface just above the tissue level for opposing an overlying portion of a prosthesis anchored elsewhere in the jaw to form a non-retentive rest or support for accepting down pressure from the prosthesis. The implant member is relatively short and can be installed in distal jaw regions without interference with the mandibular nerve. A bore is cut out in the jaw for receiving the implant, inserting the implant and an attached healing screw in the implant. The implant site is closed and osseointegration takes place over an extended period. Subsequently, the implant site is uncovered, the healing screw is removed, and the rest factor member is secured in the implant.

I claim:  
     
       1. A dental implant assembly for supporting as a rest factor the distal end of a denture anchored elsewhere in the jaw, comprising: 
       implant means for embedding in the distal region of the jawbone including a first part for projecting into and osseointegrating with the jawbone and a second part for projecting up to just above the tissue level;  
       the first part being relatively thin and having a predetermined height less than the distance between the top of a patient's jawbone at the implant site and the underlying region of the mandibular nerve;  
       the second part having an upper rest surface for supporting but not being connected to overlying portions of a denture anchored elsewhere in the jaw to resist biting pressure on the tissue and bone; and  
       the first part comprising a thin disc-shaped member having a downwardly projecting annular rim and a central spigot projecting downwardly from the disc-shaped member.  
     
     
       2. The assembly as claimed in  claim 1 , wherein said first part comprises an implant member and the second part comprises a rest factor releasably securable to the implant member. 
     
     
       3. The assembly as claimed in  claim 2 , including a plurality of implant members in a range of different sizes, the members having outer diameters in the range from about 4.25 to 6 mm. 
     
     
       4. The assembly as claimed in  claim 2 , including a plurality of implant members in a range of different heights from 2 to 4.5 mm. 
     
     
       5. The assembly as claimed in  claim 1  wherein the first part has a height no greater than its diameter. 
     
     
       6. The assembly as claimed in  claim 1 , wherein the first part has a selected diameter slightly less than the width of the alveolar crest at the implant site. 
     
     
       7. The assembly as claimed in  claim 6 , wherein the selected diameter is 1 mm less than the width of the alveolar crest. 
     
     
       8. The assembly as claimed in  claim 1 , wherein the first part has a height no greater than 4.5 mm. 
     
     
       9. The assembly as claimed in  claim 8 , wherein the first part has a height of between 2 to 4.5 mm. 
     
     
       10. The assembly as claimed in  claim 1 , wherein the rest surface has a shaped, cooperating area for non-retentive seating engagement with a correspondingly shaped mating surface on an overlying denture. 
     
     
       11. The assembly as claimed in  claim 1 , wherein the first part has a central bore in an upper face of the disc-shaped member. 
     
     
       12. The assembly as claimed in  claim 11 , wherein the second part comprises a shaft portion for engagement in the central bore of the implant member and a solid head portion projecting upwardly from the shaft portion. 
     
     
       13. The assembly as claimed in  claim 12 , wherein the extension portion is generally cylindrical with an upper, convex rest surface. 
     
     
       14. The assembly as claimed in  claim 11 , wherein the bore has an upper threaded portion and a non-threaded, lower extension portion, the second part having a shaft portion with a corresponding threaded upper portion and non-threaded lower portion for mating engagement in said implant member bore. 
     
     
       15. The assembly as claimed in  claim 14 , wherein said implant member bore and rest factor shaft portion have upper ends having matching tapers. 
     
     
       16. A dental implant assembly for supporting as a rest factor the distal end of a denture anchored elsewhere in the jaw, comprising: 
       implant means for embedding in the distal region of the jawbone including a first part for projecting into and osseointegrating with the jawbone and a second part for projecting up to just above the tissue level;  
       the first part being relatively thin and having a predetermined height less than the distance between the top of a patient's jawbone at the implant site and the underlying region of the mandibular nerve;  
       the second part having an upper rest surface for supporting but not being connected to overlying portions of a denture anchored elsewhere in the jaw to resist biting pressure on the tissue and bone;  
       the first part comprising a thin disc-shaped member having a downwardly projecting annular rim; and  
       axially extending spaced grooves in the outer surface of the annular rim for restricting rotation of the embedded implant.  
     
     
       17. A dental implant assembly for supporting as a rest factor the distal end of a denture anchored elsewhere in the jaw, comprising; 
       implant means for embedding in the distal region of the jawbone including a first part for projecting into and osseointegrating with the jawbone and a second part for projecting up to just above the tissue level;  
       the first part being relatively thin and having a predetermined height less than the distance between the top of a patient's jawbone at the implant site and the underlying region of the mandibular nerve;  
       the second part having an upper rest surface for supporting but not being connected to overlying portions of a denture anchored elsewhere in the jaw to resist biting pressure on the tissue and bone;  
       the first part comprising a generally cylindrical member having a downwardly depending annular rim, and a central spigot projecting downwardly from the cylindrical member, the central spigot having a length in the range from 1 to 2 mm.  
     
     
       18. A combined denture and support assembly, comprising: 
       a denture of more than one tooth;  
       an anchor securing one end of the denture to the jawbone;  
       support means for freely supporting a distal region of the denture at a selected location to the rear of the first bicuspid, the support means comprising a first part for embedding in the jawbone at the selected location and a second part for projecting up to at least the tissue level, the second part having an upper rest surface for supporting but not being connected to the denture and for accepting biting pressure from the denture; and  
       the first part comprising a thin disc-shaped member having a downwardly projecting annular rim and a central spigot depending downwardly from the disc-shaped member to define an annular cavity between the spigot and rim.  
     
     
       19. The assembly as claimed in  claim 18 , wherein said first part extends no more than about 4 mm into the jawbone. 
     
     
       20. The assembly as claimed in  claim 19 , wherein said first part has a diameter in the range from 4 mm to 6 mm. 
     
     
       21. The assembly as claimed in  claim 18 , wherein said second part extends up to between ½ to 1 mm above the tissue level. 
     
     
       22. The assembly as claimed in  claim 18 , wherein the first part comprises a flat, disc-shaped member having a downwardly projecting peripheral rim. 
     
     
       23. The assembly as claimed in  claim 22 , wherein the first part has a height of 2 mm and the rim projects 1 mm below the undersurface of the disc-shaped member. 
     
     
       24. A dental implant assembly for embedding in the jawbone of a patient, comprising: 
       an implant member for embedding in and osseointegrating with the jawbone of a patient at a selected site;  
       an attachment member for securing to the implant member after osseointegration;  
       the implant member having an externally-unthreaded upper end portion with  and a central bore, the attachment member and central bore of the implant member having interengageable securing means for releasably securing the attachment member to the implant member, and a  an externally-threaded stem portion depending downwardly from the upper end portion for engagement with a recess in the jawbone of shape and dimensions matching those of the stem portion;  
       the stem portion having an annular indent at its lower end; 
       the stem portion having outwardly projecting screw threads wherein the spacing between adjacent threads is substantially the same, and the height of said outwardly projecting screw threads, is substantially the same, over the entire threaded length of said stem portion; and  
       the threads comprising multiple lead threads.  
     
     
       25. The assembly as claimed in  claim 24 , wherein the threads comprise triple lead threads. 
     
     
       26. The assembly as claimed in  claim 24 , wherein the threads comprise quadruple lead threads. 
     
     
       27. The assembly as claimed in  claim 25 , wherein the threads are of square cross-section. 
     
     
       28. The assembly as claimed in  claim 24 , wherein the spacing between adjacent threads is at least 1 mm and the threads run parallel to one another. 
     
     
       29. The assembly as claimed in  claim 28 , wherein the gap between adjacent threads is larger than the width of each individual thread. 
     
     
       30. The assembly as claimed in  claim 24 , wherein the threads project out to a distance of ½ mm from the surface of the stem portion. 
     
     
       31. The assembly as claimed in  claim 24 , wherein the stem portion has an upper end and a lower end and the threads start at a position spaced below the upper end of the stem portion. 
     
     
       32. The assembly as claimed in  claim 31 , wherein the threads terminate at a position spaced above the lower end of the stem portion. 
     
     
       33. The assembly as claimed in  claim 24 , wherein the central bore projects downwardly into the stem portion of the implant member. 
     
     
       34. The assembly as claimed in  claim 24 , wherein the upper end portion of the implant member comprises an annular ring and an inwardly tapering rim projecting upwardly from the annular ring. 
     
     
       35. The assembly as claimed in  claim 24 , including a wrench element projecting from the upper end portion of said insert member for engagement with a tool for inserting the implant member, the wrench element having a bore aligned with the central bore of said insert member. 
     
     
       36. The assembly as claimed in  claim 35 , wherein the wrench element has a twelve-sided outer wrench engaging surface. 
     
     
       37. The assembly as claimed in  claim 24 , including a plurality of implant members in a range of different heights from 2 to 13 mm. 
     
     
       38. A dental implant assembly for embedding in the jawbone of patient, comprising: 
       an implant member for embedding in and osseointegrating with the jawbone of a patient at a selected site;  
       an attachment member for securing to the implant member after osseointegration;  
       the implant member having an upper end portion with a central bore, the attachment member and central bore of the implant member having interengageable securing means for releasably securing the attachment member to the implant member, and a stem portion depending downwardly from the upper end portion for engagement with a recess in the jawbone of shape and dimensions matching those of the stem portion;  
       the stem portion having an annular indent at its lower end; and  
       the attachment member comprising a rest factor member having an upper rest surface for supporting, but not being connected to, overlying portions of a denture anchored elsewhere in the jaw, the rest factor member having an upper, dome-shaped portion and a downwardly depending stem portion for engagement in said implant member bore, the rest surface comprising the upper end of said dome-shaped portion.  
     
     
       39. The assembly as claimed in  claim 38 , including a plurality of rest factor members having dome-shaped portions of different heights in the range from 1.5 mm. to 3.5 mm. 
     
     
       40. The assembly as claimed in  claim 39 , in which said rest factor members have total heights in the range from 2 mm. to 4.5 mm. 
     
     
       41. The assembly as claimed in  claim 38 , wherein said dome-shaped portion has a hex indent at its upper end for engagement with a hex tool for insertion of the rest factor member into an implant member bore. 
     
     
       42. An implant member for embedding in a patient's jawbone for attachment to other dental devices, the member comprising: 
       a generally cylindrical body having an externally-unthreaded upper end portion for projecting above the jawbone,and,a  extending downwardly from said upper end portion, an externally-threaded lower stem portion for insertion in a recess prepared in a patient's jawbone;  
       the upper end portionsaid implant member having a central bore for insertion of a portion of a dental device to be attached to the implant member; and  
       the lower end  stem portion having an outer cylindrical surface and a plurality of multiple lead threads projecting outwardly from the outer surface, said multiple lead threads extending over said outer surface and wherein the spacing between adjacent threads is substantially the same, and the height of said outwardly projecting threads is substantially the same, over the entire threaded surface.  
     
     
       43. The implant member as claimed in  claim 42 , wherein the upper end portion includes a cylindrical ring portion of diameter greater than said cylindrical surface of the lower end portion, and an inwardly tapered rim portion projecting upwardly from said ring portion. 
     
     
       44. The implant member as claimed in  claim 43 , wherein said ring portion has a diameter equal to the diameter of said threads. 
     
     
       45. The implant member as claimed in  claim 43 , wherein said upper end portion has a height less than that of the lower end portion. 
     
     
       46. An implant member for embedding in a patient's jawbone for attachment to other dental devices, the member comprising: 
         a body having an externally - unthreaded upper end portion and, extending downwardly from said upper end portion, an externally - threaded lower portion for insertion in a recess prepared in a patient's jawbone;    
       
         said implant member having an internal site for insertion of a portion of a dental device to be attached to the implant member; and  
       
         said lower portion having an outer surface and multiple lead threads projecting outwardly from said outer surface, said multiple lead threads extending over substantially the entire length of said externally - threaded lower portion and wherein the spacing between adjacent threads is substantially the same, and the height of said outwardly projecting threads, is approximately the same, over said substantially entire length.   
     
     
       47. The implant member as claimed in  claim 46  wherein the number of said lead threads is two, three, or four. 
     
     
       48. The implant member as claimed in  claim 46  wherein the pitch of each of said lead threads is in the range of about  9 ° to about  17 ° and the spacing between adjacent lead threads is at least about one millimeter. 
     
     
       49. The implant member as claimed in  claim 46  wherein the gaps between said lead threads are about twice the width of said lead threads. 
     
     
       50. The implant member as claimed in  claim 46  wherein the length of said implant is in the range of about two millimeters to about thirteen millimeters and the outer diameter of said implant member is in the range of about four millimeters to about six millimeters. 
     
     
       51. The implant member as claimed in  claim 46  wherein said implant is coated with a material that improves bone adhesion. 
     
     
       52. An implant member for embedding in a patient's jawbone for attachment to other dental devices, the member comprising: 
         a body having an externally - unthreaded upper end portion and, extending downwardly from said upper end portion, an externally - threaded lower portion for insertion in a recess prepared in a patient's jawbone;    
       
         said implant member having a central bore for insertion of a portion of a dental device to be attached to the implant member; and  
       
         said externally - threaded lower portion having an outer surface, and at least two separate lead threads protecting outwardly from said outer surface, said multiple lead threads extending over substantially the entire length of said lower portion and wherein the spacing between adjacent threads is substantially the same, and the height of said outwardly projecting threads, is approximately the same, over said substantially entire length.   
     
     
       53. The implant member as claimed in  claim 52  wherein the number of said lead threads is two, three, or four. 
     
     
       54. The implant member as claimed in  claim 52  wherein the pitch of each of said separate lead threads is in the range of about  9 ° to about  17 ° and the spacing between adjacent lead threads is at least about one millimeter. 
     
     
       55. The implant member as claimed in  claim 52  wherein the gaps between said separate lead threads are about twice the width of said lead. 
     
     
       56. The implant member as claimed in  claim 52  wherein the length of said implant is in the range of about two millimeters to about thirteen millimeters and the outer diameter of said implant member is in the range of about four millimeters to about six millimeters. 
     
     
       57. The implant member as claimed in  claim 52  wherein said implant is coated with a material that improves bone adhesion. 
     
     
       58. An implant member for embedding in a patient's jaw bone for attachment to other dental devices, the member comprising: 
         a body having an externally - unthreaded upper end portion and, extending downwardly from said upper end portion, an externally - threaded lower portion for insertion in a recess prepared in a patient's jawbone;    
       
         said implant member having a central bore for insertion of a portion of a dental device to be attached to the implant member; and  
       
         said externally - threaded lower portion having an outer surface and at least two threads with separate leads projecting outwardly from said outer surface, said at least two threads forming multiple lead threads extending over substantially the entire length of said lower portion and wherein the spacing between adjacent threads is approximately the same, and the height of said outwardly projecting threads, is approximately the same, over said substantially entire length.   
     
     
       59. The implant member as claimed in  claim 58  wherein the number of said lead threads is two, three, or four. 
     
     
       60. The implant member as claimed in  claim 58  wherein the pitch of each of said separate lead threads is in the range of about  9 ° to about  17 ° and the spacing between adjacent lead threads is at least about one millimeter. 
     
     
       61. The implant member as claimed in  claim 58  wherein the gaps between said separate lead threads are about twice the width of said lead. 
     
     
       62. The implant member as claimed in  claim 58  wherein the length of said implant is in the range of about two millimeters to about thirteen millimeters and the outer diameter of said implant member is in the range of about four millimeters to about six millimeters. 
     
     
       63. The implant member as claimed in  claim 58  wherein said implant is coated with a material that improves bone adhesion.