Process for producing a shape memory spiral rotary file

A method for manufacturing at least one nonlinear file comprising the steps of:

• providing a linear file having a shaft and a file axis;
• providing a first fixture having a first mating portion and a second mating portion, each mating portion including a surface, at least one of the surfaces of the first and second mating portions having a first file groove for receiving the shaft, the first file groove extending along a first groove plane that is defined by a first groove axis and one or more first displacement members;
• inserting a first portion of the shaft into the first file groove so that the file axis along the first portion of the shaft and the first groove axis along the first file groove are generally coaxial;
• moving at least one of surfaces towards one another so that a first displacement member of the one or more first displacement members displaces the first portion of the shaft from the file axis along the first groove plane thereby forming a first offset portion of the shaft, the first offset portion of the shaft and the file axis defining a first file plane;
• heating the first offset portion of the shaft while inserted in the first fixture to a temperature from 200° C. to less than the melting point of the file for a time period greater than 5 minutes but less than 640 minutes to shape-set the first offset portion of the shaft thereby forming a shape-set nonlinear file;
• removing the shape-set nonlinear file from the first fixture;
• providing a second fixture having a first mating portion and a second mating portion, each mating portion including a surface, at least one of the surfaces of the first and second mating portions having a second file groove for receiving a nonlinear shaft of the shape-set nonlinear file, the second file groove having a second groove axis, one or more second displacement members, and a second groove opening that extends along the at least one of the surfaces of the first and second mating portions, the second groove opening generally corresponding to the shape of the first offset portion along the first file plane;
• inserting a first portion of the nonlinear shaft into the second groove opening;
• moving at least one of surfaces towards one another so that a first displacement member of the one or more second displacement members displaces the first portion of the nonlinear shaft away from the first file plane thereby forming a second offset portion of the nonlinear file;
• and
• heating the second offset portion of the shaft while inserted in the second fixture to a temperature from 200° C. to less than the melting point of the file for a time period greater than 5 minutes but less than 640 minutes to shape-set the second offset portion of the nonlinear file thereby forming a shape-set three-dimensional nonlinear file.

A method for manufacturing at plurality of nonlinear files comprising the steps of:

• providing a plurality of files having a shaft and a file axis;
• providing a first fixture having a first mating portion and a second mating portion, each mating portion including a surface with a plurality of first file grooves having a first groove opening for receiving at least a portion of the shafts of the plurality of files, the first file grooves of the first mating portion surface corresponding to the opposing first file groove of the second mating portion, wherein the groove openings include a base surface having one or more first displacement members;
• inserting a first portion of the shafts into the first file grooves along the groove openings, wherein the groove openings generally correspond to the shape of the first portion of the shafts along the file axes;
• moving at least one of surfaces towards one another so that a first displacement member of the one or more first displacement members displaces the first portion of the shafts from the file axes thereby forming a plurality first offset portions of the shafts, each first offset portion of each shaft and each file axis define a first file plane;
• heating the first offset portions of the shafts while inserted in the first fixture to a temperature from 200° C. to less than the melting point of the file for a time period from 5 minutes to 640 minutes to shape-set the first offset portions of the shafts thereby forming a plurality of shape-set nonlinear files;
• removing the shape-set nonlinear files from the first fixture;
• providing a second fixture having a first mating portion and a second mating portion, each including a surface, the surfaces of the first and second mating portions having a plurality of second file grooves with second groove openings extending along the respective surface, the second file grooves of the first mating portion surface corresponding to the opposing first file grooves of the second mating portion, wherein the second groove openings include a base surface having one or more second displacement members;
• inserting a first portion of a nonlinear shafts of the nonlinear files into the second groove openings;
• moving at least one of surfaces towards one another so that a first displacement member of the one or more second displacement members of each of the second file grooves displaces the first portion of the nonlinear shafts away from the first file planes thereby forming a second offset portion of the nonlinear files;
• and
• heating the second offset portion of the nonlinear shafts while inserted in the second fixture to a temperature from 200° C. to less than the melting point of the files for a time period from 5 minutes to 640 minutes to shape-set the second offset portion of the nonlinear shafts thereby forming a plurality of shape-set three-dimensional nonlinear files.