scholarly journals Evaluation of the Effect of Needle Tilting Angle on Irrigant Flow in the Root Canal Using Side-Vented Needle by an Unsteady Computational Fluid Dynamics Model

2016 ◽  
Vol 6 (1) ◽  
pp. 1
Author(s):  
Ozkan Adiguzel ◽  
Mehmet Gokhan Gokcen ◽  
Ali Bahadir Olcay
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Shear Stress ◽  
Wall Shear Stress ◽  
Root Canal ◽  
Cfd Model ◽  
Dynamics Model ◽  
Computational Fluid Dynamics Model ◽  
Tilting Angle ◽  
Wall Shear

Aim: The Irrigant flow dynamics has strong influence on the root canal cleaning effectiveness. The aim of this study was to evaluate the effect of needle tilting angle on irrigant flow inside a prepared root canal during final irrigation with a side-vented needle using a validated Computational Fluid Dynamics (CFD) model. Methodology: To analyze the irrigant flow a CFD model with tilting angles of 0 and 2 degrees was created. The irrigant flow in the apical root canal was simulated. Computations were carried out for two selected flow rates of 0.26 and 0.78 mL/s to evaluate the velocity and turbulence quantities along the solution domain. Results: In addition to velocity and pressure distribution at the apex, wall shear stress distribution, vorticity and turbulent intensity results were obtained for needle tilting angle of 0 and 2 degrees. In the case of turbulent flows where the flow rate was higher, irrigation is better; however, higher apical pressures were observed for both tilting angles. Although the effect of tilting angle of two degrees for laminar flow was slightly better than zero degrees, the effect of tilting was significant for the turbulent flow case. Wall shear stress distribution, vorticity and turbulent intensity results were consistent with each other. Conclusions: A small tilting angle of 2 degrees had an effect on irrigation effectiveness which could be clearly observed from the wall shear stress, vorticity and velocity distribution results. The velocity distribution results obtained at the symmetry plane should be evaluated with the wall shear stress values together to observe the complete fluid dynamics structure inside the root canal.  How to cite this article: Adiguzel O, Gokcen MG, Olcay AB. Evaluation of the Effect of Needle Tilting Angle on Irrigant Flow in the Root Canal Using Side-Vented Needle by an Unsteady Computational Fluid Dynamics Model. Int Dent Res 2016;6:1-8.  Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Efficient Computational Fluid Dynamics Model for Transient Laminar Flow Modeling: Pressure Wave Propagation and Velocity Profile Changes

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
Nuno M. C. Martins ◽  
Bruno Brunone ◽  
Silvia Meniconi ◽  
Helena M. Ramos ◽  
Dídia I. C. Covas
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Shear Stress ◽  
Wall Shear Stress ◽  
Laboratory Data ◽  
Time Shift ◽  
Axial Component ◽  
Cfd Model ◽  
Flow Acceleration ◽  
Wall Shear

In this paper, the analysis of fast laminar transients in pressurized pipes is developed using a computational fluid dynamics (CFD) model, combined with the Zielke model and laboratory data. The systematic verification of the performance of the CFD model executed in the first part of the paper allows defining the most efficient set of the discretization parameters capable of capturing the main features of the examined transient. In this framework, the crucial role of radial discretization is pointed out. In the second part of the paper, the refined and efficient CFD model is used to examine some aspects of interest for understanding the dynamics of transients. Specifically, the uniformity of the instantaneous pressure distributions along the pipe radius, which validates the results of the most popular quasi-two-dimensional (2D) models, has been revealed. Moreover, it has been shown that the strongest link between the wall shear stress and the axial component of the velocity occurs in the region close to the pipe wall as well as that the time-shift between the wall shear stress and the local instantaneous flow acceleration increases significantly as time elapses.

scholarly journals Velocity and wall shear stress of 18% EDTA irrigation solution flow in the removal of Ca(OH)2 with computational fluid dynamic analysis

2019 ◽  
Vol 31 (1) ◽  
pp. 25
Author(s):  
Anna Muryani ◽  
Hendra Dian Adhita Dharsono ◽  
Zuleika Zuleika ◽  
Mochammad Agoes Moelyadi ◽  
Fajar Fatriadi
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Shear Stress ◽  
Wall Shear Stress ◽  
Calcium Hydroxide ◽  
Root Canal ◽  
Cfd Analysis ◽  
Canal Wall ◽  
Irrigation Solution ◽  
Wall Shear

Introduction: Ethylene Diamine Tetra Acetic Acid (EDTA) 18% irrigation solution is one of the chelating agents that able to remove calcium hydroxide (Ca(OH)2) from the root canal wall. Failure of root canal treatment can be caused by the presence of residual calcium hydroxide in the root canal wall, thus blocking the bond between the medication and root canal filling material with the root canal wall. This study was aimed to observe the EDTA 18% flow in removing the Ca(OH)2 using CFD analysis. Methods: This research was descriptive. Cleanliness of the root canal wall from Ca(OH)2 medicament using EDTA 18% irrigation was analysed using the CFD method with test specimens in the form of resin blocks made according to the characteristics of the root canal. The irrigation needle used was side-vented with a position of 3 mm from the apical tooth. Stage analysis of root canal geometry was performed using Computational Fluid Dynamics (CFD) analysis to observe the characteristics of irrigation solutions in root canals in 3D. Results: The streamlined characteristics of EDTA 18% irrigation solution showed a unique behaviour due to the features of the side-vent shaped irrigation needle. Irrigation flow in the crown area of the inlet (side-vented irrigation needle) showed low velocity so that the fluid flow when exiting the inlet was more towards the apical than the outlet (root canal orifice). Conclusion: Velocity and wall shear stress of EDTA 18% showed the results validation conformity between experimental and CFD, that the maximum velocity of EDTA 18% is 19 ms-1 and EDTA 18% wall shear stress is 1.56 KPa for calcium hydroxide removal observed from the CFD study. Keywords: Computational fluid dynamics, EDTA 18%, calcium hydroxide (Ca(OH)2), velocity, wall shear stress

Verification and Validation of a Detonation Computational Fluid Dynamics Model

2016 ◽  
Vol 366 ◽  
pp. 40-46
Author(s):  
Rui Li Wang ◽  
Xiao Liang ◽  
Wen Zhou Lin ◽  
Xue Zhe Liu ◽  
Yun Long Yu
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Cfd Simulation ◽  
Verification And Validation ◽  
Cfd Model ◽  
Dynamics Model ◽  
Computational Fluid Dynamics Model ◽  
Primary Means ◽  
Computational Fluid Dynamics Cfd ◽  
2D Space

Verification and validation (V&V) are the primary means to assess the accuracy and reliability in computational fluid dynamics (CFD) simulation. V&V of the multi-medium detonation CFD model is conducted by using our independently-developed software --- Lagrangian adaptive hydrodynamics code in the 2D space (LAD2D) as well as a large number of benchmark testing models. Specifically, the verification of computational model is based on the basic theory of the computational scheme and mathematical physics equations, and validation of the physical model is accomplished by comparing the numerical solution with the experimental data. Finally, some suggestions are given about V&V of the detonation CFD model.

Comparison of morphological and rheological conditions between conventional and eversion carotid endarterectomy using computational fluid dynamics – a pilot study

Vascular ◽  
2014 ◽  
Vol 23 (5) ◽  
pp. 474-482 ◽  
Author(s):  
S Demirel ◽  
D Chen ◽  
Y Mei ◽  
S Partovi ◽  
H von Tengg-Kobligk ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Shear Stress ◽  
Wall Shear Stress ◽  
Carotid Endarterectomy ◽  
Patient Specific ◽  
Specific Data ◽  
Computational Fluid Dynamics Analysis ◽  
Carotid Bulb ◽  
Wall Shear

Purpose: To compare postoperative morphological and rheological conditions after eversion carotid endarterectomy versus conventional carotid endarterectomy using computational fluid dynamics. Basic methods: Hemodynamic metrics (velocity, wall shear stress, time-averaged wall shear stress and temporal gradient wall shear stress) in the carotid arteries were simulated in one patient after conventional carotid endarterectomy and one patient after eversion carotid endarterectomy by computational fluid dynamics analysis based on patient specific data. Principal findings: Systolic peak of the eversion carotid endarterectomy model showed a gradually decreased pressure along the stream path, the conventional carotid endarterectomy model revealed high pressure (about 180 Pa) at the carotid bulb. Regions of low wall shear stress in the conventional carotid endarterectomy model were much larger than that in the eversion carotid endarterectomy model and with lower time-averaged wall shear stress values (conventional carotid endarterectomy: 0.03–5.46 Pa vs. eversion carotid endarterectomy: 0.12–5.22 Pa). Conclusions: Computational fluid dynamics after conventional carotid endarterectomy and eversion carotid endarterectomy disclosed differences in hemodynamic patterns. Larger studies are necessary to assess whether these differences are consistent and might explain different rates of restenosis in both techniques.

NUMERICAL SIMULATION OF HEMODYNAMICS IN PORTAL VEIN WITH THROMBOSIS BY COMPUTATIONAL FLUID DYNAMICS

2014 ◽  
Vol 14 (06) ◽  
pp. 1440006 ◽  
Author(s):  
XINKAI WANG ◽  
GUOJIE LI ◽  
BIN CHEN ◽  
YANSONG PU ◽  
PENG NIE ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Shear Stress ◽  
Wall Shear Stress ◽  
Portal Vein ◽  
Mechanical Damage ◽  
Maximum Velocity ◽  
Vein System ◽  
Vein Thrombosis ◽  
Wall Shear

Portal vein thrombosis (PVT) is an important complication that is associated with cirrhotic portal hypertension. The etiology is as yet unclear but could be closely related to the hemodynamics of the portal vein system. This paper investigated the hemodynamics in the portal vein model, both with and without thrombosis, as well as the effect of obstructions on the hemodynamics of the portal vein system using the computational fluid dynamics (CFD) method. PVT can probably develop in the inlets of the portal vein as well as the left/right branches of the portal vein because the distribution of wall shear stress satisfies the conditions for PVT formation based upon the simulation of the hemodynamics in the normal portal vein model. According to the above results, geometric models for a portal vein with a thrombus were constructed and the influence of different degrees (26%, 39%, 53% and 64%) of obstructions was studied. In the model with the maximum obstruction (64% blocked), the maximum velocity of portal vein (PV) increased up to twice than in the model without thrombosis, and the maximum wall shear stress of PV in the model with thrombosis (64% blocked) increased up to 9.4 Pa, whereas it was only 1.9 Pa in the model without thrombosis (nearly one fifth of the maximum wall shear stress). Excessive wall shear stress may cause mechanical damage to the blood vessels and induce physiological changes.

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