Effect of curing light emission spectrum on the nanohardness and elastic modulus of two bulk-fill resin composites

2016 ◽  
Vol 32 (4) ◽  
pp. 535-550 ◽  
Author(s):  
Yaser Issa ◽  
David C. Watts ◽  
Daniel Boyd ◽  
Richard B. Price
Keyword(s):  
Elastic Modulus ◽  
Emission Spectrum ◽  
Light Emission ◽  
Resin Composites ◽  
Curing Light

scholarly journals Influence of Different Concentration and Ratio of a Photoinitiator System on the Properties of Experimental Resin Composites

2017 ◽  
Vol 28 (6) ◽  
pp. 726-730 ◽  
Author(s):  
Caio Vinícius Signorelli Grohmann ◽  
Eveline Freitas Soares ◽  
Eduardo José Carvalho Souza-Junior ◽  
William Cunha Brandt ◽  
Regina Maria Puppin-Rontani ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Flexural Strength ◽  
Tertiary Amine ◽  
Water Sorption ◽  
Water Solubility ◽  
Distilled Water ◽  
Resin Composites ◽  
Amine Concentration ◽  
One Way Anova

Abstract The aim in this study was to evaluate the influence of different ratio of camphorquinone/tertiary amine concentration on the flexural strength (FS), elastic modulus (EM), degree of conversion (DC), yellowing (YL), water sorption (WS) and water solubility (WSL) of experimental composites. Thus, acrylate blends were prepared with different camphorquinone (CQ) and amine (DABE) concentrations and ratios by weight: (CQ/DABE%): 0.4/0.4% (C1), 0.4/0.8% (C2), 0.6/0.6% (C3), 0.6/1.2% (C4), 0.8/0.8% (C5), 0.8/1.6% (C6), 1.0/1.0% (C7), 1.0/2.0% (C8), 1.5/1.5% (C9), 1.5/3.0% (C10). For the FS and EM, rectangular specimens (7x2x1 mm, n=10) were photo-activated by single-peak LED for 20 s and tested at Instron (0.5 mm/min). Then, the same specimens were evaluated by FTIR for DC measurement. For YL, disks (5x2 mm, n=10) were prepared, light-cured for 20 s and evaluated in spectrophotometer using the b aspect of the CIEL*a*b* system. For WS and WSL, the volume of the samples was calculated (mm³). For WS and WSL, composites disks (5x0.5 mm, n=5) were prepared. After desiccation, the specimens were stored in distilled water for 7 days and again desiccated, in order to measure the WS and WSL. Data were submitted to one-way ANOVA and Tukey’s test (5%). The groups C8, C9 and C10 showed higher DC, EM and YL means, compared to other composites. Therefore, the FS and WS values were similar among all groups. Also, C1, C2 and C3 presented higher WSL in 7 days, compared to other composites. In general, higher concentrations of camphorquinone promoted higher physical-mechanical properties; however, inducing higher yellowing effect for the experimental composites

scholarly journals Flexural Properties and Elastic Modulus of Different Esthetic Restorative Materials: Evaluation after Exposure to Acidic Drink

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Andrea Scribante ◽  
Marco Bollardi ◽  
Marco Chiesa ◽  
Claudio Poggio ◽  
Marco Colombo
Keyword(s):  
Elastic Modulus ◽  
Flexural Strength ◽  
Water Immersion ◽  
Testing Machine ◽  
Distilled Water ◽  
Resin Composites ◽  
Restorative Material ◽  
Universal Testing ◽  
Restorative Materials ◽  
Acidic Beverages

Background. Acidic beverages, such as soft drinks, can produce erosion of resin composites. The purpose of the present study was to investigate mechanical properties of different esthetic restorative materials after exposure to acidic drink. Methods. Nine different composites were tested: nanofilled (Filtek Supreme XTE, 3M ESPE), microfilled hybrid (G-ænial, GC Corporation), nanohybrid Ormocer (Admira Fusion, Voco), microfilled (Gradia Direct, GC Corporation), microfilled hybrid (Essentia, GC Corporation), nanoceramic (Ceram.X Universal, Dentsply De Trey), supranano spherical hybrid (Estelite Asteria, Tokuyama Dental Corporation), flowable microfilled hybrid (Gradia Direct Flo, GC Corporation), and bulk fill flowable (SureFil SDR flow, Dentsply De Trey). Thirty specimens of each esthetic restorative material were divided into 3 subgroups (n=10): specimens of subgroup 1 were used as control, specimens of subgroup 2 were immersed in 50 ml of Coca Cola for 1 week, and specimens of subgroup 3 were immersed in 50 ml of Coca Cola for 1 month. Flexural strength and elastic modulus were measured for each material with an Instron Universal Testing Machine. Data were submitted to statistical analysis. Results. After distilled water immersion, nanofilled composite showed the highest value of both flexural strength and elastic modulus, but its flexural values decreased after acidic drink immersion. No significant differences were reported between distilled water and acidic drink immersion for all other materials tested both for flexural and for elastic modulus values. Conclusions. Even if nanofilled composite showed highest results, acidic drink immersion significantly reduced flexural values.

LIGHT EMISSION DURING EVAPORATION OF Ge IN AN Ar-GAS ATMOSPHERE

1996 ◽  
Vol 03 (01) ◽  
pp. 499-504
Author(s):  
Y. SASAKI ◽  
J. SATO ◽  
A. KASUYA ◽  
Y. NISHINA
Keyword(s):  
Emission Spectrum ◽  
Emission Intensity ◽  
Light Emission ◽  
Evaporation Process ◽  
Vapor Density ◽  
Gas Atmosphere ◽  
High Emission ◽  
Evaporation Source ◽  
Ar Gas ◽  
High Emission Intensity

We have observed light emission from Ar atoms [Ar(I)], Ge atoms [Ge(I)]/clusters[Ge2], and Ge ions [Ge(II)] during the evaporation process of Ge in an Ar-gas atmosphere of a few Torr. The Ar(I) lines are observed regardless of whether the crucible is empty or filled with Ge. Ar atoms are excited through discharge initiated by electrons thermionically emitted from the hot W wire heating the crucible and accelerated by the potential applied to the wire. Since the emission due to Ge is observed only when the Ar(I) lines are observed, it is concluded that Ge atoms are excited by excited Ar atoms and possibly ions. Intensities of Ar(I) lines decrease by transferring energy to Ge atoms/clusters if the density of Ge vapor is high. Emission intensity diminishes with distance from the crucible surrounded by a heat reflector and a water-cooled shroud, dropping most rapidly for Ge(II), and progressively less rapidly for Ge(I), Ar(I), and Ge2. The Ge(II) lines are stronger for lower Ar pressures and for lower Ge vapor density, while the Ge2 line is stronger for higher Ar pressures. The relative intensities of Ar(I), Ge(I), GE(II), and Ge2 also depend on the structure of the evaporation source. Reabsorption of emitted light by Ge clusters modifies the profile of the emission spectrum at ~3.7 and 4.3 eV.

Time-dependent nanoindentation behavior of high elastic modulus dental resin composites

2010 ◽  
Vol 25 (3) ◽  
pp. 529-536 ◽  
Author(s):  
Yijun Wang ◽  
Isabel K. Lloyd
Keyword(s):  
Elastic Modulus ◽  
Volume Fraction ◽  
Resin Composite ◽  
Acrylic Resin ◽  
Resin Matrix ◽  
Resin Composites ◽  
Dental Resin ◽  
Elastic Plastic ◽  
High Elastic Modulus ◽  
Continuous Stiffness Measurement

Nanoindentation and the viscous-elastic–plastic (VEP) model developed by Oyen and Cook for lightly filled thermoplastic polymer composites were used to characterize the elastic modulus, hardness, and viscoelastic response of a new high elastic modulus dental resin composite. The VEP model was used because loading rate studies indicated a viscous component in the loading/unloading response of our highly filled, thermosetting acrylic resin composites. Increasing the volume fraction of our high modulus filler increased the elastic modulus and hardness and decreased the viscous response in our composites. Coupling the filler and resin matrix with a commercial coupling agent like Metaltite or MPTMS (3-methacryloxypropyltrimethoxysilane) that ionically bonds to the filler and covalently bonds to the matrix decreases the viscous response and increases the hardness of the composite. The coupling agents did not affect the elastic modulus. The ability of the VEP model to predict load–displacement trajectories and the correlation of the elastic modulus and hardness values determined from the VEP model with those from the direct continuous stiffness measurement mode nanoindentation measurements indicate that the VEP model can be extended to highly filled, thermosetting systems. This is valuable since the potential to predict elastic, plastic, and viscous contributions to behavior should be valuable in the design and understanding of future highly filled resin composite systems.

scholarly journals The Nanomechanical and Tribological Properties of Restorative Dental Composites after Exposure in Different Types of Media

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Hong-Yi Fan ◽  
Xue-Qi Gan ◽  
Yang Liu ◽  
Zhuo-Li Zhu ◽  
Hai-Yang Yu
Keyword(s):  
Elastic Modulus ◽  
Scanning Probe Microscopy ◽  
Wear Behavior ◽  
Dental Composites ◽  
Nanoindentation Test ◽  
Wear Depth ◽  
Resin Composites ◽  
Acidic Solutions ◽  
Commercial Resin ◽  
Different Types

The aim of this study was to evaluate the effects of various acidic solutions on the surface mechanical properties of commercial resin composites with different microstructures (Filtek Z350 XT, TPH3, Durafill, and Superlux). Specimens were immersed in orange juice, cola, and distilled water for 5 days and the nanohardness, elastic modulus, and wear behavior of the samples were determined via the nanoindentation test and a reciprocating nanoscratch test. The nanoscratch morphology was observed using scanning electron microscopy (SEM) and the wear depth was recorded by scanning probe microscopy (SPM). The results indicate that the nanofilled resin composites had the greatest hardest and highest elastic modulus, whereas the microfilled composites exhibited the lowest nanohardness and elastic modulus values. SEM observations showed that all resin composites underwent erosion and surface degradation after immersion in acidic solutions. Furthermore, the wear resistance was influenced by the composition of the acidic solution and was correlated with the nanohardness and elastic modulus. The dominant wear mechanism changed from plastic deformation to delamination after immersion in acidic solutions.

scholarly journals Effect of the composite curing light mode on polymerization shrinkage of resin composites

2012 ◽  
Vol 15 (1) ◽  
Author(s):  
Ozden Ozel Bektas ◽  
Feridun Hürmüzlü ◽  
Diğdem Eren
Keyword(s):  
Resin Composites ◽  
Polymerization Shrinkage ◽  
Light Mode ◽  
Curing Light

scholarly journals Polymerization Behavior and Mechanical Properties of High-Viscosity Bulk Fill and Low Shrinkage Resin Composites

2017 ◽  
Vol 42 (6) ◽  
pp. E177-E187 ◽  
Author(s):  
S Shibasaki ◽  
T Takamizawa ◽  
K Nojiri ◽  
A Imai ◽  
A Tsujimoto ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Flexural Strength ◽  
Resin Composite ◽  
High Viscosity ◽  
The Other ◽  
Light Irradiation ◽  
Volumetric Shrinkage ◽  
Resin Composites ◽  
Polymerization Shrinkage

SUMMARY The present study determined the mechanical properties and volumetric polymerization shrinkage of different categories of resin composite. Three high viscosity bulk fill resin composites were tested: Tetric EvoCeram Bulk Fill (TB, Ivoclar Vivadent), Filtek Bulk Fill posterior restorative (FB, 3M ESPE), and Sonic Fill (SF, Kerr Corp). Two low-shrinkage resin composites, Kalore (KL, GC Corp) and Filtek LS Posterior (LS, 3M ESPE), were used. Three conventional resin composites, Herculite Ultra (HU, Kerr Corp), Estelite ∑ Quick (EQ, Tokuyama Dental), and Filtek Supreme Ultra (SU, 3M ESPE), were used as comparison materials. Following ISO Specification 4049, six specimens for each resin composite were used to determine flexural strength, elastic modulus, and resilience. Volumetric polymerization shrinkage was determined using a water-filled dilatometer. Data were evaluated using analysis of variance followed by Tukey's honestly significant difference test (α=0.05). The flexural strength of the resin composites ranged from 115.4 to 148.1 MPa, the elastic modulus ranged from 5.6 to 13.4 GPa, and the resilience ranged from 0.70 to 1.0 MJ/m3. There were significant differences in flexural properties between the materials but no clear outliers. Volumetric changes as a function of time over a duration of 180 seconds depended on the type of resin composite. However, for all the resin composites, apart from LS, volumetric shrinkage began soon after the start of light irradiation, and a rapid decrease in volume during light irradiation followed by a slower decrease was observed. The low shrinkage resin composites KL and LS showed significantly lower volumetric shrinkage than the other tested materials at the measuring point of 180 seconds. In contrast, the three bulk fill resin composites showed higher volumetric change than the other resin composites. The findings from this study provide clinicians with valuable information regarding the mechanical properties and polymerization kinetics of these categories of current resin composite.

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