关键词: 超声冲洗, 超声工作尖, 牙本质碎屑, 冲洗剂, 清洁效果

Abstract:

Ultrasonic irrigation has been increasingly used in root canal therapy. The oscillating ultrasonic tips can induce cavitation and acoustic streaming，which can produce shear stress along the root canal wall and remove debris and bacteria. Nickel-titanium tips can adjust the anatomic modality of root canal preferably. There is no significant difference between a smooth wire and a cutting K-file as the ultrasonic tip on the removal of dentine debris and smear layer. Passive ultrasonic irrigation（PUI）removes more bacteria，smear layer and dentine debris and is an important supplement for cleaning complicated root canal system. Irrigation with sodium hypochlorite is effective. The use volume of irrigation is more important than density. PUI with a pulsation pattern is more effective in removing dentine debris than a continuous oscillation. The insertion direction and depth of the ultrasonic tip are affective. In this paper the mechanism of action，instrumentation，efficiency and relevant factors of PUI were reviewed in order to guide the practical application.

Key words: ultrasonic irrigation, ultrasonic tips, dentine debris, irrigant, cleaning effects