Abstract: A root canal therapy device with a mechanical vibration mode and a rotation drive mode includes a head, a handle, a first flexible drive shaft and a second flexible drive shaft. The head includes an outer main part, a mandrel part for mounting a root canal file, a first drive input shaft part and a second drive input shaft part. The mandrel part is mounted in the outer main part. A first drive motor and a second drive motor are disposed on the handle. The invention has the following beneficial effects: the root canal file can rotate and vibrate during root canal preparation, so that the wall of a root canal is efficiently cut by the file; and the file can also vibrate, so that cutting resistance and cutting temperature are effectively reduced, a smear layer is avoided, and the quality and efficiency of root canal preparation are improved.

Abstract: A NiTi alloy root canal file with a flexibility gradient includes a tip segment (F1), a middle segment (F2) and a root segment (F3) divided along the axis of the NiTi alloy root canal file with the flexibility gradient. The internal microstructure of the tip segment (F1) of the root canal file is martensite M-phase, the internal microstructure of the middle segment (F2) is R-phase, and the internal microstructure of the root segment (F3) is austenite A-Phase. The present invention further provides a manufacturing method for the NiTi alloy root canal file with the flexibility gradient. The beneficial effect of the present invention is effectively improving safety in use.

Abstract: A NiTi alloy root canal file with a flexibility gradient includes a tip segment (F1), a middle segment (F2) and a root segment (F3) divided along the axis of the NiTi alloy root canal file with the flexibility gradient. The internal microstructure of the tip segment (F1) of the root canal file is martensite M-phase, the internal microstructure of the middle segment (F2) is R-phase, and the internal microstructure of the root segment (F3) is austenite A-Phase. The present invention further provides a manufacturing method for the NiTi alloy root canal file with the flexibility gradient. The beneficial effect of the present invention is effectively improving safety in use.

Abstract: A NiTi alloy root canal file with a flexibility gradient, having a tip, middle portion and rear portion divided along the longitudinal direction. The internal microstructure of the tip is martensite, of the rear portion is austenite, and of the middle portion is a combination of martensite and austenite. The microstructure of martensite is continuously reduced and the microstructure of austenite is continuously increased as the distance from the tip increases. A manufacturing method for the NiTi alloy root canal file with a flexibility gradient. As the internal microstructure of the NiTi alloy root canal file with a flexibility gradient gradually changes along the axial direction and the strength also gradually changes, the flexibility and strength show a gradient change along the axial direction of the root canal file, providing excellent cutting property, high anti-fatigue life and significantly improving operation performance, safety, and life of the root canal files.