scholarly journals Effect on Physical and Mechanical Properties of Conventional Glass Ionomer Luting Cements by Incorporation of All-Ceramic Additives: An In Vitro Study

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Runki Saran ◽  
Nagraj P. Upadhya ◽  
Kishore Ginjupalli ◽  
Arul Amalan ◽  
Bharath Rao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Film Thickness ◽  
Setting Time ◽  
Average Particle ◽  
Glass Ionomer ◽  
Ceramic Powders ◽  
Luting Cements ◽  
Luting Cement ◽  
All Ceramic

Introduction. Glass ionomer cements (GICs) are commonly used for cementation of indirect restorations. However, one of their main drawbacks is their inferior mechanical properties. Aim. Compositional modification of conventional glass ionomer luting cements by incorporating two types of all-ceramic powders in varying concentrations and evaluation of their film thickness, setting time, and strength. Material & Methods. Experimental GICs were prepared by adding different concentrations of two all-ceramic powders (5%, 10, and 15% by weight) to the powder of the glass ionomer luting cements, and their setting time, film thickness, and compressive strength were determined. The Differential Scanning Calorimetry analysis was done to evaluate the kinetics of the setting reaction of the samples. The average particle size of the all-ceramic and glass ionomer powders was determined with the help of a particle size analyzer. Results. A significant increase in strength was observed in experimental GICs containing 10% all-ceramic powders. The experimental GICs with 5% all-ceramic powders showed no improvement in strength, whereas those containing 15% all-ceramic powders exhibited a marked decrease in strength. Setting time of all experimental GICs progressively increased with increasing concentration of all-ceramic powders. Film thickness of all experimental GICs was much higher than the recommended value for clinical application. Conclusion. 10% concentration of the two all-ceramic powders can be regarded as the optimal concentration for enhancing the glass ionomer luting cements’ strength. There was a significant increase in the setting time at this concentration, but it was within the limit specified by ISO 9917–1:2007 specifications for powder/liquid acid-base dental cements. Reducing the particle size of the all-ceramic powders may help in decreasing the film thickness, which is an essential parameter for the clinical performance of any luting cement.

Experimental Study on the Effects of Internal Erosion on the Physical and Mechanical Properties of Tailings Under Unsteady Seepage

2021 ◽  
Author(s):  
Rong Gui ◽  
Guicheng He
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Shear Strength ◽  
Average Particle Size ◽  
Physical And Mechanical Properties ◽  
Internal Erosion ◽  
Average Particle ◽  
Sand Column ◽  
Sedimentary Characteristics ◽  
Seepage Erosion

Abstract In this paper, the hydraulic sedimentary model was established to investigate the effects of dry beach slope on the sedimentary characteristics of tailings, and the sand column model was built to investigate the effects of seepage erosion on the physical and mechanical properties of sedimentary tailings under unsteady seepage.The results show that the slope of dry beach have a great effect on the sedimentary characteristics of tailings, the average particle size of tailings decreases along the slope of dry beach, and the larger the slope, the more obvious the stratification of the tailings. The migration of fine-grained tailings caused by seepage erosion increases the permeability of the tailings and reduces the shear strength of the tailings. After seepage erosion,the average particle size of 1#tailings sample, 2#tailings sample and 3#tailings sample increased by 6.4%, 12.0% and 2.4% respectively, the hydraulic conductivity of 1# tailings sample, 2# tailings sample and 3# tailings increased by 27.2%,17.9%, and 15.3% respectively after internal erosion, and the shear strength of 1#tailings sample, 2#tailings sample and 3#tailings sample tailings sample decreased by 20.9 %, 15.1% and 12.4% respectively.

Fabrication of A356-based rolled composites reinforced by Ni–P-coated bimodal ceramic particles

2016 ◽  
Vol 232 (10) ◽  
pp. 803-815 ◽  
Author(s):  
R Kheirifard ◽  
N Beigi Khosroshahi ◽  
R Azari Khosroshahi ◽  
R Taherzadeh Mousavian ◽  
D Brabazon
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Average Particle Size ◽  
Microstructural Characterization ◽  
Rolling Process ◽  
Stir Casting ◽  
Ceramic Particle ◽  
Average Particle ◽  
Ceramic Particles ◽  
Sic Particles

Three arrangements of reinforced A356-based composites were fabricated. Samples with 3 wt% Al2O3 (average particle size: 170 µm), 3 wt% SiC (average particle size: 15 µm), and 3 wt% of mixed Al2O3–SiC powders (each reinforcement 1.5 wt%) were fabricated. The novel fabrication process of two-step stir casting followed by rolling was utilized. Analysis of the effect of using bimodal-sized ceramic particles and process parameters on the microstructure and mechanical properties of the composites was examined. Electroless deposition of nickel was used to improve the wettability of the ceramic reinforcements by the molten metal. From microstructural characterization, it was found that fine SiC particles were agglomerated, including when coated with Ni–P. It was also revealed that the rolling process broke the fine silicon platelets within the A356 matrix, which were mostly observed around the Al2O3 particles. The processed microstructure of the composite was altered in comparison to conventionally cast A356 MMC by translocation of the fractured silicon particles, by improving the distribution of fine SiC particles, and by elimination of porosities remaining after casting. A good bonding quality at matrix–ceramic interface was formed during casting and no significant improvement was found in this regard after the rolling process. The mechanical properties of the composites tested showed that the samples, which contained the bimodal ceramic particle distribution of coarse Al2O3 and fine SiC particles produced the highest levels of composite strength and hardness.

scholarly journals Effect of Luting Cements On the Bond Strength to Turkom-Cera All-Ceramic Material

2018 ◽  
Vol 6 (3) ◽  
pp. 548-553 ◽  
Author(s):  
Bandar M. A. Al–Makramani ◽  
Abdul A. A. Razak ◽  
Mohamed I. Abu–Hassan ◽  
Fuad A. Al–Sanabani ◽  
Fahad M. Albakri
Keyword(s):  
Bond Strength ◽  
Shear Bond Strength ◽  
Testing Machine ◽  
Glass Ionomer Cement ◽  
Resin Cement ◽  
Glass Ionomer ◽  
Luting Cement ◽  
Significant Difference ◽  
All Ceramic ◽  
Ionomer Cement

BACKGROUND: The selection of the appropriate luting cement is a key factor for achieving a strong bond between prepared teeth and dental restorations.AIM: To evaluate the shear bond strength of Zinc phosphate cement Elite, glass ionomer cement Fuji I, resin-modified glass ionomer cement Fuji Plus and resin luting cement Panavia-F to Turkom-Cera all-ceramic material.MATERIALS AND METHODS: Turkom-Cera was used to form discs 10mm in diameter and 3 mm in thickness (n = 40). The ceramic discs were wet ground, air - particle abraded with 50 - μm aluminium oxide particles and randomly divided into four groups (n = 10). The luting cement was bonded to Turkom-Cera discs as per manufacturer instructions. The shear bond strengths were determined using the universal testing machine at a crosshead speed of 0.5 mm/min. The data were analysed using the tests One Way ANOVA, the nonparametric Kruskal - Wallis test and Mann - Whitney Post hoc test.RESULTS: The shear bond strength of the Elite, Fuji I, Fuji Plus and Panavia F groups were: 0.92 ± 0.42, 2.04 ± 0.78, 4.37 ± 1.18, and 16.42 ± 3.38 MPa, respectively. There was the statistically significant difference between the four luting cement tested (p < 0.05).CONCLUSION: the phosphate-containing resin cement Panavia-F exhibited shear bond strength value significantly higher than all materials tested.

scholarly journals 3D Online Submicron Scale Observation of Mixed Metal Powder's Microstructure Evolution in High Temperature and Microwave Compound Fields

2014 ◽  
Vol 2014 ◽  
pp. 1-5
Author(s):  
Dan Kang ◽  
Feng Xu ◽  
Xiao-fang Hu ◽  
Bo Dong ◽  
Yu Xiao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
High Temperature ◽  
Microstructure Evolution ◽  
Diffusion Mechanism ◽  
Average Particle Size ◽  
Average Particle ◽  
Reconstruction Method ◽  
Neck Size ◽  
Submicron Scale

In order to study the influence on the mechanical properties caused by microstructure evolution of metal powder in extreme environment, 3D real-time observation of the microstructure evolution of Al-Ti mixed powder in high temperature and microwave compound fields was realized by using synchrotron radiation computerized topography (SR-CT) technique; the spatial resolution was enhanced to 0.37 μm/pixel through the designed equipment and the introduction of excellent reconstruction method for the first time. The process of microstructure evolution during sintering was clearly distinguished from 2D and 3D reconstructed images. Typical sintering parameters such as sintering neck size, porosity, and particle size of the sample were presented for quantitative analysis of the influence on the mechanical properties and the sintering kinetics during microwave sintering. The neck size-time curve was obtained and the neck growth exponent was 7.3, which indicated that surface diffusion was the main diffusion mechanism; the reason was the eddy current loss induced by the external microwave fields providing an additional driving force for mass diffusion on the particle surface. From the reconstructed images and the curve of porosity and average particle size versus temperature, it was believed that the presence of liquid phase aluminum accelerated the densification and particle growth.

Micromorphology of Porosity Related to Electrical Resistance of Dental Luting Cements

2018 ◽  
Vol 766 ◽  
pp. 13-18
Author(s):  
Mana Sriyudthsak ◽  
Yaninee Kosaiyakanon ◽  
Fan Pui Luen ◽  
Kamolporn Wattanasirmkit ◽  
Viritpon Srimaneepong
Keyword(s):  
Electrical Property ◽  
Phosphate Glass ◽  
Electrical Resistance ◽  
Zinc Phosphate ◽  
High Porosity ◽  
Micro Ct ◽  
Glass Ionomer ◽  
Luting Cements ◽  
Luting Cement ◽  
Zinc Phosphate Glass

The aim was to investigate the relation between micromorphology of porosity and electrical resistance of dental luting cements. Five dental luting cements were evaluated: zinc phosphate, glass ionomer, and three types of resin luting cements. Porosity of the specimen was analyzed by micro-CT and electrical resistance of cement was measured at voltage of 125 V up to 30 days and solubility of each specimen was calculated. It showed that the resin luting cements provided the highest electrical resistance regardless of amount of porosity. Zinc phosphate and glass ionomer had high porosity and the lowest resistance (14 and 3 kΩ, respectively). It was found that the electrical resistance of luting cement was not directly affected by the amount of porosity, but it seems to be related to pore connection. There is no correlation between electrical resistance and percentage of porosity but the morphology of porosity may have an influence on the electrical property of luting cement. Models of pore connection were proposed to explain the electrical resistance of luting cement.

scholarly journals Effects of Mixing Procedure on Characteristics of Luting Cements : Part 1. Effects of Mixing Time on Setting Time and Film Thickness

1994 ◽  
Vol 48 (2) ◽  
pp. 342-349
Author(s):  
Hiroshi Kakigawa ◽  
Masafumi Yamanaka ◽  
Hisao Nomasa ◽  
Yasuhiro Fukamizu ◽  
Shigeru Ohara ◽  
...  
Keyword(s):  
Film Thickness ◽  
Mixing Time ◽  
Setting Time ◽  
Luting Cements

scholarly journals Effect of Porosity on Compressive Strength of Resin Modified Glass Ionomer Luting Cements

2020 ◽  
Vol 17 (2) ◽  
Author(s):  
Al-Kadhim AHA ◽  
Abdullah H
Keyword(s):  
Compressive Strength ◽  
Linear Relationship ◽  
Image Analyzer ◽  
Distilled Water ◽  
Glass Ionomer ◽  
Cement Type ◽  
Luting Cements ◽  
Luting Cement ◽  
Significant Difference ◽  
Resin Modified Glass Ionomer

Introduction: The purpose of this study was to decide on the relation between types of mixing and the porosity of diameter (1-100) µm and compressive strength of RMGIC. Methods: Fifteen specimens 6mm height and 4mm in diameter were prepared for each type of luting cement and were stored in distilled water at 37° C for 24 hours. The compressive strength was determined. The fractured surfaces of 10 randomly selected specimens of each cement type were analyzed using SEM at 250 times magnification, and five photomicrographs were taken at five random places. All the photomicrographs were analyzed using image analyzer software to determine the amount and size of porosity present. Results: There was no significant difference in compressive strength between different mixing methods, but it had a significant impact by increasing the percentage of porosity of diameter (1-100) µm in diameter of RMGIC. There was no linear relationship between compressive strength and porosity (1-100) µm in diameter for both types of luting cements (P>0.05). Conclusion: No significant differences in compressive strength were found using different mixing methods. The size and number of porosity in the specimens of encapsulated cements were greater than those of hand-mixed cements. The porosity (1-100) µm in diameter and the compressive strength bore no linear relationship to each other.

scholarly journals Experimental study on mechanical properties of steel - sand interface

2020 ◽  
Vol 143 ◽  
pp. 01030
Author(s):  
Zhaoxiao Fang ◽  
Weijiang Wang ◽  
Zhaoli Fang
Keyword(s):  
Mechanical Properties ◽  
Particle Size ◽  
Friction Coefficient ◽  
Average Particle Size ◽  
Average Particle ◽  
Shear Tests ◽  
Axial Pressure ◽  
Interface Shear ◽  
Interface Friction ◽  
Sand Particles

The interface between steel and sand can be regard as a steel-sand system, and its mechanical properties have an important role in many geotechnical applications. The mechanical properties of various steel-sand interfaces classified by sand mean particle size D50 were investigated through interface shear tests. The results show that for a given steel-sand interface, the peak strength of the interface increase with increasing axial pressure. As the D50 value increases, the cohesions for steel-sand interfaces decrease, while the friction angles of the interfaces first increase and then decrease. In the process of shearing, the shrinkage of steel-sand interface occurs, mainly due to the broken of sand particles. The decrease in interface friction coefficients due to an increase in axial pressure was observed. Particle size distribution has a significant effect on the interface friction coefficient of steel-sand interface. When the average particle size D50 changes from 0.1 mm to 0.47 mm, the friction coefficient of steel-sand interface increases by 134%-161%.

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