Implant with high primary stability and accelerated secondary stability

Abstract

An implant for implantation into bone tissue includes an elongated body having an outer surface. The outer surface hast least one thread. The thread makes a number of turns around the body of the implant and includes a root, a flank and a crest. The root and a segment of the flank have a roughened portion compared to the crest. A method of forming an implant having a threaded outer surface including a root, a flank, and a crest includes treating the threaded outer surface at only the root and a portion of the flank while the crest remains untreated.

What is claimed is: 
     
         1 . An implant for implantation into bone tissue having an exterior surface comprising:
 an elongated body having an upper portion configured to receive a prosthesis, a lower portion for being submerged in said bone tissue, and an outer surface; and   at least one thread on said outer surface making a plurality of turns around the elongated body between the lower portion and the upper portion, the at least one thread including a root, a flank, and a crest, wherein the root and a segment of the flank have a roughened portion relative to the crest.   
     
     
         2 . The implant of  claim 1 , wherein the plurality of turns has a helical shape. 
     
     
         3 . The implant of  claim 1 , where an inner section of the flank relative to a central axis of the implant has the roughened portion relative to the crest while an outer section of the flank relative to the central axis has roughness similar to the crest. 
     
     
         4 . The implant of  claim 1 , wherein the thread includes a transition region between the root and the crest. 
     
     
         5 . The implant of  claim 4 , wherein the transition region includes a portion of gradually decreasing roughness in a direction of the crest. 
     
     
         6 . The implant of  claim 1 , further comprising a self-tapping region. 
     
     
         7 . The implant of  claim 6 , wherein the self-tapping region is smooth relative to the roughened portion of the root and the roughened portion of the flank. 
     
     
         8 . The implant of  claim 1 , wherein the crest has a flattened shape. 
     
     
         9 . The implant of  claim 1 , wherein the crest has a rounded shape. 
     
     
         10 . The implant of  claim 1 , wherein the crest has a peaked shape. 
     
     
         11 . The implant of  claim 1 , wherein the root has a flattened shape. 
     
     
         12 . The implant of  claim 1 , wherein the root has a rounded shape. 
     
     
         13 . The implant of  claim 1 , wherein the root has a narrow-angled shape. 
     
     
         14 . An implant for implantation into bone tissue, the implant having:
 at least one thread including a root, a flank, and a crest, the thread making a plurality of helical turns around the implant; and   a roughened portion adjacent to the root of the thread, the roughened portion helically extending along a length of the implant leaving the crest of the thread relatively smooth.   
     
     
         15 . The implant of  claim 14 , where an inner section of the flank relative to a central axis of the implant has the roughened portion relative to the crest while an outer section of the flank relative to the central axis has roughness similar to the crest. 
     
     
         16 . The implant of  claim 14 , wherein the roughened portion has a graduated roughness pattern. 
     
     
         17 . A method of forming an implant having a threaded outer surface including a root, a flank, and a crest, the method comprising:
 treating the threaded outer surface at only the root and a portion of the flank such that the crest remains untreated.   
     
     
         18 . The method of  claim 17 , wherein treating the threaded outer surface comprises blasting the threaded outer surface. 
     
     
         19 . The method of  claim 17 , wherein treating the threaded outer surface is performed using a blast nozzle. 
     
     
         20 . The method of  claim 17 , wherein treating the threaded outer surface comprises blasting the threaded outer surface along a helical locus.