Endodontic instruments

Abstract

A method of manufacturing endodontic instruments is disclosed. Each of the instruments includes a substantially non-cutting pilot portion, a relatively short working portion, and a flexible shank portion which is of a substantially smaller average circumferential span than the working portion. The working portion of the instrument has a maximum circumferential span larger than that of the blank from which it is made. The instrument may have a handle at its distal end for manual manipulation, or may be adapted for attachment to a mechanical handpiece. The non-cutting pilot, the short length of the working portion, and the flexibility of the shank combine to allow the instrument to be used in curved root canals without causing undue change in the natural root canal contours.

1 . A method for manufacturing a set of endodontic instruments, each of said instruments having a non-working shank portion, a working portion, and a pilot portion, the method comprising: 
 providing a set of blanks having identical circumferential spans;    positioning and compressing at least a portion of said blank adjacent a die having walls defining at least partially the shape-and circumferential span of the working portion, said compressing is of sufficient force to deform said portion of said blank in contact with said walls into a shape reflecting said walls to form the working portion;    forming the pilot portion adjacent the working portion;    wherein the shank portion of each of the instruments in the set has a longitudinal axis and is of substantially the same circumferential span of the blank and each working portion has a different circumferential span from the blank.    
   
   
       2 . The method of  claim 1  wherein said working portion comprises an average thickness and each working portion of one instrument in the set has a different average thickness from the working portion of the other instruments in the set.  
   
   
       3 . The method of  claim 1  further comprising treating at least a portion of each of the instruments comprising at least a portion of the shank, the working portion, the pilot portion or combinations thereof.  
   
   
       4 . The method of  claim 3  further comprises attaching said treated portion to a handle.  
   
   
       5 . The method of  claim 1  wherein said working portion comprises projecting sections extending outwardly from the shank portion; projecting sections in one plane; projecting sections twisting not more than 359° about the longitudinal axis of the shank; projecting sections that are non-intersecting; or combinations thereof.  
   
   
       6 . The method of  claim 3  wherein said treating comprises coating, sandblasting, anodizing, ion implantation, etching, electro-polishing, heat setting, cryogenic treatment, or combinations thereof.  
   
   
       7 . The method of  claim 3  wherein said treating is performed after the instrument has been formed, prior to the compression process, or during the manufacturing of the blank.  
   
   
       8 . The method of  claim 1  wherein said working portion comprises at least two projection sections.  
   
   
       9 . The method of  claim 1  wherein said working portion comprises at least four projecting sections.  
   
   
       10 . The method of  claim 1  wherein said pilot portion pilot portion comprises substantially non-cutting portions, abrasive surfaces or combinations thereof.  
   
   
       11 . A method for manufacturing a set of endodontic instruments, each of said instruments having a non-working shank portion, a working portion and a pilot portion, the method comprising: 
 providing a set of blanks having varying circumferential spans;    positioning and compressing at least a portion of each said blank adjacent a die having walls defining at least partially the shape and circumferential span of the working portion, said compressing is of sufficient force to deform said portion of said blank in contact with said walls into a shape reflecting said walls to form the working portion; and    forming the pilot portion adjacent the working portion;    wherein each of said blank in the set has a circumferential span substantially smaller than the circumferential span of the working portion and substantially the same as the circumferential span of the non-working shank of each instrument in the set and each instrument in the set having a working portion with a predetermined circumferential span that is different from that of any other instrument in the set.    
   
   
       12 . The method of  claim 11  wherein the compression force is adjusted so that the thicknesses of the working surfaces in the set of instruments are substantially the same.  
   
   
       13 . The method of  claim 11  wherein said working portion comprises projecting sections extending outwardly from the shank portion; projecting sections in one plane; projecting sections twisting not more than 359° about the longitudinal axis; projecting sections that are non-intersecting; or combinations thereof.  
   
   
       14 . The method of  claim 11  further comprising treating at least a portion of each of the instruments comprising at least a portion of the shank, the working portion, the pilot portion or combinations thereof.  
   
   
       15 . The method of  claim 14  wherein said treating comprises coating, sandblasting, anodizing, ion implantation, etching, electro-polishing, heat setting, cryogenic treatment, or combinations thereof.  
   
   
       16 . A set of endodontic instruments, each comprising: 
 a relatively short working portion having a proximal end and a distal end;    a pilot portion adjacent the proximal end of the working portion; and    a flexible shank portion adjacent the distal end of said working portion, said shank portion having a longitudinal axis, a distal end and a proximal end, at least a portion of the shank portion has a substantially smaller average circumferential span than the working portion, and a different circumferential span from that of other instruments in the set;    wherein the thickness of each of the working portions in the set is substantially the same as that of others in the set, and the circumferential span of one working portion is different from that of others in the set.    
   
   
       17 . The instrument of  claim 16  wherein at least a portion of each of the instruments including the shank, the working portion, the pilot portion or combinations thereof has been treated.  
   
   
       18 . The instrument of  claim 16  wherein each of said working portions comprises at least one projecting section, said projection section does not twist about the longitudinal axis of more than 359 degrees; does not intersect any other projection of the same instrument; or combinations thereof.  
   
   
       19 . The instrument of  claim 16  wherein said working portion is flat.  
   
   
       20 . The instrument of  claim 16  wherein said working portion comprises at least one projection lying substantially in a plane of the flat working portion.  
   
   
       21 . The instrument of  claim 16  wherein said instrument comprises a handle attached to the distal end of the shank portion.  
   
   
       22 . The instrument of  claim 16  wherein said pilot portion comprises substantially non-cutting portions, abrasive surfaces or combinations thereof.  
   
   
       23 . A method for manufacturing a set of groups of endodontic instruments having a shank portion, a working portion and a pilot portion, comprising: 
 providing a set of groups of blanks, each group of blanks having a different circumferential span from other groups in the set;    positioning and compressing at least a portion of each of said blank adjacent a die having walls defining at least partially the shape and circumferential span of the working portion, said compressing is of sufficient force to deform said portion of said blank in contact with said walls into a shape reflecting said walls to form the working portion; and    forming the pilot portion adjacent the working portion;    wherein each said working portion has a circumferential span substantially larger than the circumferential span of the blank from which it is made, and the working portion of one instrument in the group has a different circumferential span and thickness from the others in the same group.    
   
   
       24 . The method of  claim 23  wherein the thickness of the working portion of one instrument in one group is the same as that of an instrument in another group.  
   
   
       25 . The method of  claim 23  wherein the thicknesses of the working portions in the set are different.  
   
   
       26 . The method of  claim 23  wherein the number of groups is fewer than the number of instruments in the set.  
   
   
       27 . The method of  claim 23  further comprising treating at least a portion of each of the instruments comprising at least a portion of the shank, the working portion, the pilot portion or combinations thereof.  
   
   
       28 . The method of  claim 27  wherein said treating is performed after the instrument has been formed, prior to the compression process, or during the manufacturing of the blank.  
   
   
       29 . The method of  claim 23  wherein said pilot portion pilot portion comprises substantially non-cutting portions, abrasive surfaces or combinations thereof.  
   
   
       30 . A set of groups of endodontic instruments, each instrument comprising: 
 a relatively short working portion having a proximal end and a distal end;    a pilot portion adjacent the proximal end of the working portion; and    a flexible shank portion adjacent the distal end of the working portion, said shank portion having a longitudinal axis, at least a portion of the shank portion has a substantially smaller average circumferential span than the working portion, and has a different circumferential span from that of instruments in other groups;    wherein the thickness and circumferential span of one of the working portions in one group is different from those of others in the group.    
   
   
       31 . The instrument of  claim 30  wherein said at least a portion of each of the instruments including the shank, the working portion, the pilot portion or combinations thereof has been treated.  
   
   
       32 . The instrument of  claim 30  wherein said working portion comprises projecting sections extending outwardly from the shank portion; projecting sections in one plane; projecting sections twisting not more than 359° about the longitudinal axis of the shank; projecting sections that are non-intersecting; or combinations thereof.  
   
   
       33 . The instrument of  claim 32  wherein said working portion comprises at least two projection sections.  
   
   
       34 . The instrument of  claim 30  wherein the thickness of the working portion of an instrument in one group is the same as an instrument in another group.  
   
   
       35 . The instrument of  claim 30  wherein the thickness of the working portion of an instrument in one group is the same as an instrument in every other group.  
   
   
       36 . The instrument of  claim 30  wherein the thickness of the working portion all instruments in the set is different.  
   
   
       37 . The instrument of  claim 31  further comprises a handle attached to the treated portion of the shank portion.