Experiments in Fluids

, Volume 53, Issue 6, pp 1841–1853

Role of the confinement of a root canal on jet impingement during endodontic irrigation

  • B. Verhaagen
  • C. Boutsioukis
  • G. L. Heijnen
  • L. W. M. van der Sluis
  • M. Versluis
Research Article

DOI: 10.1007/s00348-012-1395-0

Cite this article as:
Verhaagen, B., Boutsioukis, C., Heijnen, G.L. et al. Exp Fluids (2012) 53: 1841. doi:10.1007/s00348-012-1395-0


During a root canal treatment the root canal is irrigated with an antimicrobial fluid, commonly performed with a needle and a syringe. Irrigation of a root canal with two different types of needles can be modeled as an impinging axisymmetric or non-axisymmetric jet. These jets are investigated experimentally with high-speed Particle Imaging Velocimetry, inside and outside the confinement (concave surface) of a root canal, and compared to theoretical predictions for these jets. The efficacy of irrigation fluid refreshment with respect to the typical reaction time of the antimicrobial fluid with a biofilm is characterized with a non-dimensional Damköhler number. The pressure that these jets induce on a wall or at the apex of the root canal is also measured. The axisymmetric jet is found to be stable and its velocity agrees with the theoretical prediction for this type of jet, however, a confinement causes instabilities to the jet. The confinement of the root canal has a pronounced influence on the flow, for both the axisymmetric and non-axisymmetric jet, by reducing the velocities by one order of magnitude and increasing the pressure at the apex. The non-axisymmetric jet inside the confinement shows a cascade of eddies with decreasing velocities, which at the apex does not provide adequate irrigation fluid refreshment.

List of symbols


velocity in r and y direction


fluid density


fluid dynamic viscosity


jet radius, diameter


flow rate

\(Re = \frac{v D}{\nu}\)

Reynolds number


distance between the needle tip and the apex or wall


distance from the plate or apex where stagnation flow holds


angle under which flow exits the needle


(root canal) cone angle


eigenvalue of the stream function inside a cavity

Copyright information

© Springer-Verlag Berlin Heidelberg 2012

Authors and Affiliations

  • B. Verhaagen
    • 1
  • C. Boutsioukis
    • 2
  • G. L. Heijnen
    • 1
  • L. W. M. van der Sluis
    • 3
  • M. Versluis
    • 1
  1. 1.Physics of Fluids Group, Faculty of Science and Technology and Institute for Biomedical Technology and Technical Medicine MIRAUniversity of TwenteEnschedeThe Netherlands
  2. 2.Physics of Fluids Group, Faculty of Science and Technology and MESA+ Institute for NanotechnologyUniversity of TwenteEnschedeThe Netherlands
  3. 3.Department of Conservative Dentistry and Endodontics, Faculty of DentistryPaul Sabatier UniversityToulouse CEDEX 9France