scholarly journals Shrinkage / stress reduction and mechanical properties improvement in restorative composites formulated with thio-urethane oligomers

2018 ◽  
Vol 78 ◽  
pp. 235-240 ◽  
Author(s):  
Atais Bacchi ◽  
Jonathan A. Yih ◽  
Jacqueline Platta ◽  
Joseph Knight ◽  
Carmem S. Pfeifer
Keyword(s):  
Mechanical Properties ◽  
Stress Reduction ◽  
Shrinkage Stress ◽  
Restorative Composites

scholarly journals A study of shrinkage stress reduction and mechanical properties of nanogel-modified resin systems

2012 ◽  
Vol 48 (11) ◽  
pp. 1819-1828 ◽  
Author(s):  
JianCheng Liu ◽  
Gregory D. Howard ◽  
Steven H. Lewis ◽  
Matthew D. Barros ◽  
Jeffrey W. Stansbury
Keyword(s):  
Mechanical Properties ◽  
Stress Reduction ◽  
Shrinkage Stress ◽  
Modified Resin

scholarly journals Mechanical properties and biocompatibility of polymer infiltrated sodium aluminum silicate restorative composites

2017 ◽  
Vol 6 (1) ◽  
pp. 73-79 ◽  
Author(s):  
Huining Wang ◽  
Bencang Cui ◽  
Jing Li ◽  
Shu Li ◽  
Yuanhua Lin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Aluminum Silicate ◽  
Sodium Aluminum Silicate ◽  
Restorative Composites

scholarly journals Effect of Camphorquinone Concentration in Physical-Mechanical Properties of Experimental Flowable Resin Composites

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Dayany da Silva Alves Maciel ◽  
Arnaldo Bonfim Caires-Filho ◽  
Marta Fernandez-Garcia ◽  
Camillo Anauate-Netto ◽  
Roberta Caroline Bruschi Alonso
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Flexural Strength ◽  
Mechanical Strength ◽  
Surface Hardness ◽  
Degree Of Conversion ◽  
Bending Test ◽  
Resin Matrix ◽  
Shrinkage Stress ◽  
Depth Of Cure

The aim of this study was to evaluate the effect of camphorquinone concentration in physical-mechanical properties of experimental flowable composites in order to find the concentration that results in maximum conversion, balanced mechanical strength, and minimum shrinkage stress. Model composites based on BISGMA/TEGDMA with 70% wt filler loading were prepared containing different concentrations of camphorquinone (CQ) on resin matrix (0.25%, 0.50%, 1%, 1.50%, and 2% by weight). Degree of conversion was determined by FTIR. Surface hardness was assessed before and after 24 h ethanol storage and softening rate was determined. Depth of cure was determined by Knoop hardness evaluation at different depths. Color was assessed by reflectance spectrophotometer, employing the CIE-Lab system. Flexural strength and elastic modulus were determined by a three-point bending test. Shrinkage stress was determined in a Universal Testing Machine in a high compliance system. Data were submitted to ANOVA and Tukey’s test (α = 0.05). The increase in CQ concentration caused a significant increase on flexural strength and luminosity of composites. Surface hardness was not affected by the concentration of CQ. Composite containing 0.25% wt CQ showed lower elastic modulus and shrinkage stress when compared to others. Depth of cure was 3 mm for composite containing 1% CQ and 2 mm for the other tested composites. Degree of conversion was inversely correlated with softening rate and directly correlated with elastic modulus and shrinkage stress. In conclusion, CQ concentration affects polymerization characteristics and mechanical strength of composites. The concentration of CQ in flowable composite for optimized polymerization and properties was 1% wt of the resin matrix, which allows adequate balance among degree of conversion, depth of cure, mechanical properties, and color characteristics of these materials.

Shrinkage stress and mechanical properties of photoactivated composite resin using the argon ion laser

2009 ◽  
Vol 96 (1) ◽  
pp. 79-84 ◽  
Author(s):  
C. S. Delfino ◽  
C. S. C. Pfeifer ◽  
R. R. Braga ◽  
M. N. Youssef ◽  
M. L. Turbino
Keyword(s):  
Mechanical Properties ◽  
Composite Resin ◽  
Shrinkage Stress ◽  
Argon Ion Laser ◽  
Ion Laser ◽  
Argon Ion

Mechanical properties and ion release from bioactive restorative composites containing glass fillers and calcium phosphate nano-structured particles

2015 ◽  
Vol 31 (6) ◽  
pp. 726-733 ◽  
Author(s):  
Marina D.S. Chiari ◽  
Marcela C. Rodrigues ◽  
Tathy A. Xavier ◽  
Eugen M.N. de Souza ◽  
Victor E. Arana-Chavez ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Calcium Phosphate ◽  
Ion Release ◽  
Restorative Composites ◽  
Glass Fillers

scholarly journals Reduction of Residual Quenching Stresses in 2A14 Aluminum Alloy Tapered Cylinder Forgings via a Novel Cold Bulging Process

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 717
Author(s):  
Bingxiang Wang ◽  
Youping Yi ◽  
Shiquan Huang ◽  
Hailin He
Keyword(s):  
Mechanical Properties ◽  
Finite Element Method ◽  
Residual Stresses ◽  
Stress Reduction ◽  
Fem Simulation ◽  
Hole Drilling ◽  
Fem Simulations ◽  
Physical Experiments ◽  
Transmission Electron ◽  
Precipitated Phases

This study combined finite element method (FEM) simulations and physical experiments to develop a novel cold bulging process, with the aim of studying and mitigating the quenching residual stresses in 2A14 tapered cylinder forgings. The samples underwent cold bulging at different ratios (0–4.0%) to evaluate the residual stress reduction performance (via the hole-drilling strain-gauge method) and the improvements in their mechanical properties. The FEM simulation and experimental results revealed that our proposed cold bulging process reduced the quenching residual stresses by up to 85–87%. The density and uniformity of the precipitated phases increased along with the extent of cold bulging, as confirmed by transmission electron microscope (TEM) observations. Furthermore, compared to the unprocessed samples, the tensile and yield strengths, and elongation of the samples with 3% cold bulging were significantly enhanced (65 MPa, 55 MPa, and 1.7%, respectively).

scholarly journals A Comparative Study of the Mechanical Properties of Selected Dental Composites with a Dual-Curing System with Light-Curing Composites

Coatings ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1255
Author(s):  
Monika Domarecka ◽  
Agata Szczesio-Wlodarczyk ◽  
Michał Krasowski ◽  
Magdalena Fronczek ◽  
Tomasz Gozdek ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Flexural Strength ◽  
Comparative Study ◽  
Wide Spectrum ◽  
Shrinkage Stress ◽  
Three Point Bending ◽  
Light Curing ◽  
Dual Curing ◽  
Diametral Tensile Strength

Dual-curing composites have a wide spectrum of use in practice (rebuilding, reconstruction, and luting). The characterization of this type of material and comparative study of selected mechanical properties with light-cured materials were carried out for this paper. In this study, we used six materials with a dual-cure system—Bulk EZ, Fill-Up!, StarFill 2B, Rebilda DC, MultiCore Flow, Activa Bioactive-Restorative—and three light-cured materials—Filtek Bulk Fill Posterior, Charisma Classic, and G-aenial Universal Flo. The materials were conditioned for 24 h in water at 37 °C before testing. Selected material properties were determined: three-point bending flexural strength, diametral tensile strength, hardness, microhardness, and shrinkage stress. The highest three-point bending flexural strength (TPB) was 137.0 MPa (G-aenial Universal Flo), while the lowest amounted to 86.5 MPa (Activa Bioactive). The diametral tensile strength (DTS) values were in a range from 39.2 MPa (Rebilda DC) to 54.1 MPa (Charisma Classic). The lowest hardness (HV) value of 26 was obtained by the Activa Bioactive material, while the highest values were recorded for Filtek Bulk Fill Posterior and Charisma Classic-53. The shrinkage stress of the tested materials ranged from 6.3 MPa (Charisma Classic) to 13.2 MPa (G-aenial Universal Flo). Dual-curing composites were found to have similar properties to light-cured composites.

Sign in / Sign up

Export Citation Format

Share Document