Thermal Behavior of Teeth During Restoration Procedure With Composite: Experimental Tests and Numerical Simulation

2020 ◽  
Vol 143 (2) ◽  
Author(s):  
M. Potenza ◽  
P. Coppa ◽  
L. Cerroni ◽  
G. Bovesecchi
Keyword(s):  
Numerical Simulation ◽  
Finite Difference ◽  
Thermal Behavior ◽  
Heat Generation ◽  
Resin Composite ◽  
Experimental Tests ◽  
Cylindrical Sample ◽  
Temperature Trend ◽  
Thermal Capacitance ◽  
Hard Tissues

Abstract Different thermal mechanisms influence the tooth temperature during the reconstruction practice of tooth restoration: conduction in the hard tissues and their thermal capacitance, heat generation by composite curing, irradiation of the surface from the LED lamp, convection, and conduction to the environment. All these phenomena were considered into a numerical (finite difference, FD) model to simulate the temperature trend in a tooth during reconstruction with a resin composite addition, and results compared with experiments on cylindrical sample with a cavity filled with resin. Results demonstrate that all the phenomena have been sufficiently accurately described, and the way to apply the model to real teeth is recognized.

scholarly journals The Influence of Cement Layer Thickness on the Stress State of Metal Inlay Restorations—Photoelastic Analysis

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 599
Author(s):  
Grzegorz Sokolowski ◽  
Michal Krasowski ◽  
Agata Szczesio-Wlodarczyk ◽  
Bartlomiej Konieczny ◽  
Jerzy Sokolowski ◽  
...  
Keyword(s):  
Stress State ◽  
Layer Thickness ◽  
Resin Composite ◽  
Water Immersion ◽  
Cylindrical Sample ◽  
Resin Cement ◽  
Adhesive Resin ◽  
Cement Layer ◽  
Contraction Stress ◽  
Photoelastic Analysis

The successful restoration of teeth requires a good connection between the inlay and natural tissue. A strong bond may improve retention and reinforce tooth structure. The purpose of this study was to evaluate the influence of cement layer thickness on contraction stress generated during photopolymerization, and to determine the changes in stress state of the cement occurring during aging in water (over 84 days). Two cements were used: resin composite cement (NX3) and self-adhesive resin cement (Maxcem Elite Chroma). A cylindrical sample made of CuZn alloy was used to imitate the inlay. The stress state was measured by photoelastic analysis. The contraction stress of the inlay restoration was calculated for cement layer thicknesses of 25 µm, 100 µm, 200 µm, and 400 µm. For both tested materials, the lowest contraction stress was observed for the thinnest layer (25 µm), and this increased with thickness. Following water immersion, a significant reduction in contraction stress was observed due to hygroscopic expansion. Applying a thin layer (approximately 25 µm) of composite and self-adhesive resin cements resulted in high levels of expansion stresses (over −6 MPa) after water aging.

Numerical Simulation for Uplift Bearing Capacity and Affecting Factors of the Digging Piles in Slope Ground

2013 ◽  
Vol 423-426 ◽  
pp. 1292-1295 ◽  
Author(s):  
Xing Yun Wang ◽  
Bin Peng ◽  
Xiao Chao Tang ◽  
Lian Fan
Keyword(s):  
Numerical Simulation ◽  
Regression Analysis ◽  
Finite Difference ◽  
Bearing Capacity ◽  
Mutual Effect ◽  
Simulation Method ◽  
Affecting Factors ◽  
Slope Ratio ◽  
Nonlinear Regression Analysis ◽  
Numerical Simulation Method

Based on the numerical simulation method, this paper has established the numerical simulation method by using of finite difference software of FLAC3D through establishing interface for digging pile-soil. It can consider mutual effect of digging pile-soil. The uplift bearing capacity of the digging pile in slope ground was calculated and the affecting factors of the bearing capacity were analyzed. The results show that the uplift bearing capacity has a negative correlation with the slope ratio, and has a positive correlation with the width or height of the foundation, which can be expressed as a quadratic polynomial. But when the slope ratio is smaller than a certain extent, the capacity no longer increases. Nonlinear regression analysis of calculation data are carried out. Finally, the calculation method of uplift bearing capacity about pile in the slope is developed, which can provide a reference to specification revision and engineering.

scholarly journals Numerical simulation of gas-solid flow in an interconnected fluidized bed

2015 ◽  
Vol 19 (1) ◽  
pp. 317-328 ◽  
Author(s):  
Giuseppe Canneto ◽  
Cesare Freda ◽  
Giacobbe Braccio
Keyword(s):  
Numerical Simulation ◽  
Fluidized Bed ◽  
Experimental Tests ◽  
Solid Particles ◽  
Multiphase Model ◽  
Cold Model ◽  
Conservation Equations ◽  
Solid Flow

The gas-particles flow in an interconnected bubbling fluidized cold model is simulated using a commercial CFD package by Ansys. Conservation equations of mass and momentum are solved using the Eulerian granular multiphase model. Bubbles formation and their paths are analyzed to investigate the behaviour of the bed at different gas velocities. Experimental tests, carried out by the cold model, are compared with simulation runs to study the fluidization quality and to estimate the circulation of solid particles in the bed.

A Parallel HOFD Scheme for Direct Numerical Simulation of Turbulent Magnetically Driven Flows

2001 ◽  
Author(s):  
X. Ai ◽  
B. Q. Li
Keyword(s):  
Numerical Simulation ◽  
Finite Difference ◽  
Direct Numerical Simulation ◽  
Turbulent Flows ◽  
Parallel Machines ◽  
Higher Order ◽  
Electrically Conducting ◽  
Wide Range ◽  
Order Scheme ◽  
Higher Order Scheme

Abstract Turbulent magnetically flows occur in a wide range of material processing systems involving electrically conducting melts. This paper presents a parallel higher order scheme for the direct numerical simulation of turbulent magnetically driven flows in induction channels. The numerical method is based on the higher order finite difference algorithm, which enjoys the spectral accuracy while minimizing the computational intensity. This, coupled with the parallel computing strategy, provides a very useful means to simulate turbulent flows. The higher order finite difference formulation of magnetically driven flow problems is described in this paper. The details of the parallel algorithm and its implementation for the simulations on parallel machines are discussed. The accuracy and numerical performance of the higher order finite difference scheme are assessed in comparison with the spectral method. The examples of turbulent magnetically driven flows in induction channels and pressure gradient driven flows in regular channels are given, and the computed results are compared with experimental measurements wherever possible.

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