The new HyFlex EDM files from COLTENE constitute the fifth-generation of root canal files. HyFlex EDM NiTi files have completely new properties due to their innovative manufacturing process using electric discharge machining (EDM).
Workpieces are machined in the EDM manufacturing process by generating a potential between the workpiece and the tool. The sparks generated in this process cause the surface of the material to melt and evaporate. This creates the unique surface of the new Niti files and makes the HyFlex EDM files stronger and more fracture resistant.
This entirely unique combination of flexibility and fracture resistance makes it possible to reduce the number of files required for cleaning and shaping during root canal treatments without compromising the preservation of the root canal anatomy.
HyFlex™ EDM files exhibits high flexibility, extreme resistance to fracture and centred canal preparation.
In fact, tests have shown that HyFlex NiTi files are significantly more resistant to fatigue than conventional NiTi files. In the new HyFlex EDM NiTi files, this effect is further increased by 300-700%. The new EDM manufacturing process results in another form fit and hardness of the surface of the file.
Additionally, HyFlex NiTi have a built-in shape memory. They prevent stress during preparation by changing their spiral shape and regain their shape after heat treatment. A normal autoclaving process is enough to return the files to their original shape and to regenerate the crystal structures and resistance to fatigue.
Should the file fail to regain its shape after heat treatment, it is plastically deformed, thus increasing the risk of fracture. These files should not be used after visual inspection. The number of reuses, which can be determined by the user by visual inspection, is higher than that of conventional NiTi files.
