Our research

Recently, a new type of NiTi file has been introduced into the market, the shape memory nickel-titanium files Hyflex CM which stands for Controlled Memory. The manufacturer claims an increased flexibility compared to the conventional NiTi files, which gives the file the advantage to follow the anatomy accurately reducing the risk of file fracture, ledging, transportation or perforation.

Another ability of the Hyflex CM file is that it responds to excessive resistance by changing straightening the spirals which make further binding to the wall impossible and thus providing a high resistence to the cyclic fatigue. After sterilization the files regain their original shape and are therefore designed for multiple use.

The Hyflex manufacturer recommends a single-length technique combined with a coronal flare with Hyflex CM instruments. This technique has the advantages of reduced chair time and reduction in the number of  instruments needed to finalize the instrumentation.

The objective of our study is to evaluate the prevalence of permanent deformation in Hyflex CM of all file sizes AND to evaluate which technique (manufacturer recommended single-lenght or crown-down) results in more permanent plastic deformation.