I stopped using rotary nickel titanium files a few years ago because of problems with files breaking. I did not break that many, but just enough to make me feel a bit insecure. I went back to using stainless steel files. Recently, though, I was reading about the next generation of rotary nickel titanium, the Twisted File from SybronEndo. According to Mounce – who I consider one of the greatest endodontists – these files are very resistant to breakage if they are used properly. Has anybody used these? How do these compare with other rotary nickel titanium instrumentation? Mounce says you may be able to do a whole endo with only one file. Thoughts?
Richard E. Mounce, DDS published an article in Oral Health. May 2008, discussing the Twisted File. Below are some excerpts. The full article, as well as, other information about Twisted Files can be found at http://www.tfwithrphase.com.
The Twisted File (TF) is unsurpassed in its cutting efficiency, fracture resistance, tactile control, and the efficiencies gained from its use…A proprietary process of heating, cooling and twisting makes TF possible. TF is not ground against the material’s natural grain structure to create the cutting edges. Such grinding creates microcracks that can be future failure points due excessive to torsion and cyclic fatigue.
The heating and cooling process that the nickel titanium is subjected to optimizes its molecular phase structure that ultimately gives TF its qualities…many root anatomies will allow a single TF file to create the entire preparation. This is the first instrument ever that has possessed this flexibility and functionality…If used correctly (as described), TF will reduce instrument fracture dramatically, almost to zero…Reduced fracture rates translate to confidence, predictability, ultimately better clinical results and greater profitability…
Because TF cuts efficiently, the number of files needed to reach TWL (i.e. the minor constriction of the apical foramen) is reduced considerably…As a benefit of the heating, cooling and twisting of the metal, TF can negotiate virtually any curvature. It is very difficult to envision the clinical case that would require hand files to be preferred over TF in the apical third…The Twisted File is the first file that can be used Crown Down and/or as a Single File instrument in many cases and do so with unparalleled safety and cutting efficiency…