1. The Influence of the Oscillation Direction of an Ultrasonic File on the Cleaning Efficacy of Passive Ultrasonic Irrigation
- Author
-
Lucas W.M. van der Sluis, Michel Versluis, Lei-Meng Jiang, B. Verhaagen, Endodontologie (OUD, ACTA), Physics of Fluids, Faculty of Science and Technology, and Personalized Healthcare Technology (PHT)
- Subjects
Materials science ,REMOVING CHARACTERISTICS ,Time Factors ,Sodium Hypochlorite ,Acoustics ,Root canal ,Dentistry ,DEBRIS ,Dentin debris ,BOUNDARY-LAYERS ,Sonication ,Materials Testing ,Perpendicular ,medicine ,Dentin ,Photography ,Humans ,Ultrasonics ,ROOT CANALS ,HAND INSTRUMENTATION ,Therapeutic Irrigation ,General Dentistry ,Groove (engineering) ,Jet (fluid) ,Irrigation procedure ,Root Canal Irrigants ,Oscillation ,business.industry ,Syringes ,IR-79603 ,CYLINDERS ,medicine.anatomical_structure ,METIS-268007 ,passive ultrasonic irrigation ,Ultrasonic sensor ,Dental Pulp Cavity ,business ,Rheology ,OVAL CANALS ,Root Canal Preparation - Abstract
Introduction: The cleaning mechanisms and characteristics of passive ultrasonic irrigation (PUI) are not yet completely understood. The aim of this study was to investigate whether the oscillatory direction of the ultrasonically driven file had an influence on dentin debris removal from artificially made grooves in standardized root canals. Methods: Each of 20 ex vivo root canal models with a standard groove in the apical portion of one canal wall filled with dentin debris received PUI repeatedly, either with file oscillation toward the groove or with file oscillation perpendicular to the groove. After each irrigation procedure, the amount of dentin debris in the groove was evaluated by photographs of the groove and by scoring. The oscillations of the ultrasonic file were also visualized in vitro by using high-speed imaging at a time scale relevant to the cleaning process, order 10 microseconds. Results: A nonparametric analysis showed significantly more dentin debris reduction when the file oscillated toward the groove (P = .002). High-speed imaging showed that the oscillation of the file is in a single plane, resulting in high-velocity jets emanating from the file tip in the direction of the oscillations. Conclusions: Oscillation of the ultrasonically driven file toward the groove is more effective in removing dentin debris from the groove than oscillation perpendicular to the groove, which can be related to the fact that there is a high-velocity jet from the file tip in a single direction following the file oscillation and a relatively slow inflow in the perpendicular direction. (I Endod 2010;36:1372-1376)
- Published
- 2010