Ultrasonic irrigation flows in root canals: effects of ultrasound power and file insertion depth

A. Koulogiannis; A. D. Walmsley; P. Angeli; S. Balabani

doi:10.1038/s41598-024-54611-x

Ultrasonic irrigation flows in root canals: effects of ultrasound power and file insertion depth

A. Koulogiannis , A. D. Walmsley, P. Angeli ^*, S. Balabani ^*

^*Corresponding author for this work

Dentistry

Research output: Contribution to journal › Article › peer-review

1 Downloads (Pure)

Abstract

Ultrasonic irrigation during root canal treatment can enhance biofilm disruption. The challenge is to improve the fluid flow so that the irrigant reaches areas inaccessible to hand instrumentation. The aim of this study is to experimentally investigate how the flow field and hydrodynamic forces induced by ultrasonic irrigation are influenced by the ultrasound power and file insertion depth. A root canal phantom was 3D printed and used as a mold for the fabrication of a PDMS channel. An ultrasonic instrument with a #15 K-file provided the irrigation. The flow field was studied by means of Particle Image Velocimetry (PIV). The time averaged velocity and shear stress distributions were found to vary significantly with ultrasound power. Their maximum values increase sharply for low powers and up to a critical power level. At and above this setting, the flow pattern changes, from the high velocity and shear stress region confined in the vicinity of the tip, to one covering the whole root canal domain. Exceeding this threshold also induces a moderate increase in the maximum velocities and shear stresses. The insertion depth was found to have a smaller effect on the measured velocity and shear stresses. Due to the oscillating nature of the flow, instantaneous maximum velocities and shear stresses can reach much higher values than the mean, especially for high powers. Ultrasonic irrigation will benefit from using a higher power setting as this does produce greater shear stresses near the walls of the root canal leading to the potential for increased biofilm removal.

Original language	English
Article number	5368
Number of pages	10
Journal	Scientific Reports
Volume	14
DOIs	https://doi.org/10.1038/s41598-024-54611-x
Publication status	Published - 4 Mar 2024

Bibliographical note

Acknowledgments:
Financial support by the Engineering and Physical Sciences Research Council (EPSRC) (SONATA Grant EP/V028626/1), UCL Chemical Engineering and UCL Mechanical Engineering is gratefully acknowledged. We would like to thank our collaborators Prof. Zoe Pikramenou (and her team) and Dr. Sarah Kuehne from the University of Birmingham as well as Dr. Knut Rurack and Dr. Jeremy Bell from Bundesanstalt für Materialforschung und-prüfung (BAM). We would also like to thank Mr. William Backhouse, UCL Mechanical Engineering Technical Support team, for helping with the electric power measurements. SB would like to thank dental practitioners George Tsolakides and Charlotte Spedding for informal discussions. The authors deny any conflicts of interest related to this study.

Keywords

Root canal
Ultrasonic
Irrigation
Biofilm
Ultrasound power
Insertion depth
Particle image velocimetry
Fluid dynamics

Access to Document

10.1038/s41598-024-54611-xLicence: Creative Commons: Attribution (CC BY)

KoulogiannisA2024UltrasonicFinal published version, 10.2 MBLicence: Creative Commons: Attribution (CC BY)

Cite this

@article{9c6fb8295ac24e7bbe4a4e119baaf1d4,

title = "Ultrasonic irrigation flows in root canals: effects of ultrasound power and file insertion depth",

abstract = "Ultrasonic irrigation during root canal treatment can enhance biofilm disruption. The challenge is to improve the fluid flow so that the irrigant reaches areas inaccessible to hand instrumentation. The aim of this study is to experimentally investigate how the flow field and hydrodynamic forces induced by ultrasonic irrigation are influenced by the ultrasound power and file insertion depth. A root canal phantom was 3D printed and used as a mold for the fabrication of a PDMS channel. An ultrasonic instrument with a #15 K-file provided the irrigation. The flow field was studied by means of Particle Image Velocimetry (PIV). The time averaged velocity and shear stress distributions were found to vary significantly with ultrasound power. Their maximum values increase sharply for low powers and up to a critical power level. At and above this setting, the flow pattern changes, from the high velocity and shear stress region confined in the vicinity of the tip, to one covering the whole root canal domain. Exceeding this threshold also induces a moderate increase in the maximum velocities and shear stresses. The insertion depth was found to have a smaller effect on the measured velocity and shear stresses. Due to the oscillating nature of the flow, instantaneous maximum velocities and shear stresses can reach much higher values than the mean, especially for high powers. Ultrasonic irrigation will benefit from using a higher power setting as this does produce greater shear stresses near the walls of the root canal leading to the potential for increased biofilm removal.",

keywords = "Root canal, Ultrasonic, Irrigation, Biofilm, Ultrasound power, Insertion depth, Particle image velocimetry, Fluid dynamics",

author = "A. Koulogiannis and Walmsley, {A. D.} and P. Angeli and S. Balabani",

note = "Acknowledgments: Financial support by the Engineering and Physical Sciences Research Council (EPSRC) (SONATA Grant EP/V028626/1), UCL Chemical Engineering and UCL Mechanical Engineering is gratefully acknowledged. We would like to thank our collaborators Prof. Zoe Pikramenou (and her team) and Dr. Sarah Kuehne from the University of Birmingham as well as Dr. Knut Rurack and Dr. Jeremy Bell from Bundesanstalt f{\"u}r Materialforschung und-pr{\"u}fung (BAM). We would also like to thank Mr. William Backhouse, UCL Mechanical Engineering Technical Support team, for helping with the electric power measurements. SB would like to thank dental practitioners George Tsolakides and Charlotte Spedding for informal discussions. The authors deny any conflicts of interest related to this study.",

year = "2024",

month = mar,

day = "4",

doi = "10.1038/s41598-024-54611-x",

language = "English",

volume = "14",

journal = "Scientific Reports",

issn = "2045-2322",

publisher = "Nature Publishing Group",

}

TY - JOUR

T1 - Ultrasonic irrigation flows in root canals

T2 - effects of ultrasound power and file insertion depth

AU - Koulogiannis , A.

AU - Walmsley, A. D.

AU - Angeli , P.

AU - Balabani , S.

N1 - Acknowledgments: Financial support by the Engineering and Physical Sciences Research Council (EPSRC) (SONATA Grant EP/V028626/1), UCL Chemical Engineering and UCL Mechanical Engineering is gratefully acknowledged. We would like to thank our collaborators Prof. Zoe Pikramenou (and her team) and Dr. Sarah Kuehne from the University of Birmingham as well as Dr. Knut Rurack and Dr. Jeremy Bell from Bundesanstalt für Materialforschung und-prüfung (BAM). We would also like to thank Mr. William Backhouse, UCL Mechanical Engineering Technical Support team, for helping with the electric power measurements. SB would like to thank dental practitioners George Tsolakides and Charlotte Spedding for informal discussions. The authors deny any conflicts of interest related to this study.

PY - 2024/3/4

Y1 - 2024/3/4

N2 - Ultrasonic irrigation during root canal treatment can enhance biofilm disruption. The challenge is to improve the fluid flow so that the irrigant reaches areas inaccessible to hand instrumentation. The aim of this study is to experimentally investigate how the flow field and hydrodynamic forces induced by ultrasonic irrigation are influenced by the ultrasound power and file insertion depth. A root canal phantom was 3D printed and used as a mold for the fabrication of a PDMS channel. An ultrasonic instrument with a #15 K-file provided the irrigation. The flow field was studied by means of Particle Image Velocimetry (PIV). The time averaged velocity and shear stress distributions were found to vary significantly with ultrasound power. Their maximum values increase sharply for low powers and up to a critical power level. At and above this setting, the flow pattern changes, from the high velocity and shear stress region confined in the vicinity of the tip, to one covering the whole root canal domain. Exceeding this threshold also induces a moderate increase in the maximum velocities and shear stresses. The insertion depth was found to have a smaller effect on the measured velocity and shear stresses. Due to the oscillating nature of the flow, instantaneous maximum velocities and shear stresses can reach much higher values than the mean, especially for high powers. Ultrasonic irrigation will benefit from using a higher power setting as this does produce greater shear stresses near the walls of the root canal leading to the potential for increased biofilm removal.

AB - Ultrasonic irrigation during root canal treatment can enhance biofilm disruption. The challenge is to improve the fluid flow so that the irrigant reaches areas inaccessible to hand instrumentation. The aim of this study is to experimentally investigate how the flow field and hydrodynamic forces induced by ultrasonic irrigation are influenced by the ultrasound power and file insertion depth. A root canal phantom was 3D printed and used as a mold for the fabrication of a PDMS channel. An ultrasonic instrument with a #15 K-file provided the irrigation. The flow field was studied by means of Particle Image Velocimetry (PIV). The time averaged velocity and shear stress distributions were found to vary significantly with ultrasound power. Their maximum values increase sharply for low powers and up to a critical power level. At and above this setting, the flow pattern changes, from the high velocity and shear stress region confined in the vicinity of the tip, to one covering the whole root canal domain. Exceeding this threshold also induces a moderate increase in the maximum velocities and shear stresses. The insertion depth was found to have a smaller effect on the measured velocity and shear stresses. Due to the oscillating nature of the flow, instantaneous maximum velocities and shear stresses can reach much higher values than the mean, especially for high powers. Ultrasonic irrigation will benefit from using a higher power setting as this does produce greater shear stresses near the walls of the root canal leading to the potential for increased biofilm removal.

KW - Root canal

KW - Ultrasonic

KW - Irrigation

KW - Biofilm

KW - Ultrasound power

KW - Insertion depth

KW - Particle image velocimetry

KW - Fluid dynamics

U2 - 10.1038/s41598-024-54611-x

DO - 10.1038/s41598-024-54611-x

M3 - Article

SN - 2045-2322

VL - 14

JO - Scientific Reports

JF - Scientific Reports

M1 - 5368

ER -

Ultrasonic irrigation flows in root canals: effects of ultrasound power and file insertion depth

Abstract

Bibliographical note

Keywords

Access to Document

Fingerprint

Cite this