According to an embodiment of the present invention, provided is a Ni-Ti alloy file for a root canal cleaning process using ultrasonic wave energy. A file according to an embodiment of the present invention is formed of a Ni-Ti alloy and is heat-treated to include an R-phase at a temperature range of 36 to 45°C. The Ni-Ti alloy file of the present invention can exhibit high fracture resistance during a cleaning process and can perform an effective cleaning process without damaging a molded root canal when being used in a root canal cleaning process using ultrasonic vibration energy.본 발명의 일 실시예에 따르면, 초음파 에너지를 이용한 근관 세정에 이용될 수 있는 파일이 제공된다. 본 발명의 일 실시예에 따른 파일은 Ni-Ti 합금으로 형성되고, 36~45℃의 온도 범위에서 R-phase를 포함하도록 열처리된 것을 특징으로 한다
