ABSTRACT
INTRODUCTION: Root canal irrigation is vital to thorough debridement and disinfection, but the mechanisms that contribute to its effectiveness are complex and uncertain. Traditionally, studies in this area have relied on before-and-after static comparisons to assess effectiveness, but new in situ tools are being developed to provide real-time assessments of irrigation. The aim in this work was to measure a cross section of the velocity field in the fluid flow around a polymer rotary finishing file in a model root canal. METHODS: Fluorescent microparticles were seeded into an optically accessible acrylic root canal model. A polymer rotary finishing file was activated in a static position. After laser excitation, fluorescence from the microparticles was imaged onto a frame-transfer camera. Two consecutive images were cross-correlated to provide a measurement of a projected, 2-dimensional velocity field. RESULTS: The method reveals that fluid velocities can be much higher than the velocity of the file because of the shape of the file. Furthermore, these high velocities are in the axial direction of the canal rather than only in the direct of motion of the file. CONCLUSIONS: Particle image velocimetry indicates that fluid velocities induced by the rotating file can be much larger than the speed of the file. Particle image velocimetry can provide qualitative insight and quantitative measurements that may be useful for validating computational fluid dynamic models and connecting clinical observations to physical explanations in dental research.
Subject(s)
Dental Pulp Cavity/anatomy & histology , Root Canal Irrigants/chemistry , Therapeutic Irrigation/instrumentation , Acrylic Resins/chemistry , Equipment Design , Fluorescent Dyes , Humans , Hydrodynamics , Lasers, Solid-State , Models, Anatomic , Optical Imaging/methods , Photography/methods , Polymers/chemistry , Rheology/methods , Rotation , Surface PropertiesABSTRACT
This article focuses on the endodontic-restorative interface. The reduction of bacterial contamination via chemical-mechanical debridement during conventional endodontic treatment, in conjunction with canal obturation and timely restorative treatment using a rubber dam to prevent the microbial recontamination of the canal system, will significantly improve the clinical outcome.
