 The study found that the superlasticity of needy rotary files is lost when they are subjected to repeated cycles of loading and unloading. This phenomenon occurs because the martensite formed during cyclic loading becomes stabilized, leading to early fracturing of the file. Heat treating the files at 500 degrees Celsius for 20 minutes can restore the superlasticity of the files. This article was authored by Patricia Sanchez, Benedetta Vidi, Jesus Mina Alvarez, and others.