scholarly journals Synthesis of Bis-GMA and UDMA Nanofibers for Reinforcing Experimental resin-composites: Influence on Degree of Conversion, Depth of Cure, Flexural Strength, Flexural Modulus and Fracture Toughness

2019 ◽  
Vol 65 (2) ◽  
pp. 213-214
Author(s):  
Samy El-Safty ◽  
El-Refaie Kenawy
Keyword(s):  
Fracture Toughness ◽  
Flexural Strength ◽  
Flexural Modulus ◽  
Degree Of Conversion ◽  
Resin Composites ◽  
Depth Of Cure ◽  
Conversion Depth

scholarly journals Rapid 3 s Curing: What Happens in Deep Layers of New Bulk-Fill Composites?

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 515
Author(s):  
Danijela Marovic ◽  
Matej Par ◽  
Ana Crnadak ◽  
Andjelina Sekelja ◽  
Visnja Negovetic Mandic ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Raman Spectroscopy ◽  
Flexural Strength ◽  
Flexural Modulus ◽  
Degree Of Conversion ◽  
Resin Composites ◽  
Three Point Bending ◽  
Deep Layers ◽  
Light Curing ◽  
New Generation

This study assessed the influence of rapid 3 s light curing on the new generation of bulk-fill resin composites under the simulated aging challenge and depths up to 4 mm. Four bulk-fill materials were tested: two materials designed for rapid curing (Tetric PowerFill—PFILL; Tetric PowerFlow—PFLW) and two regular materials (Filtek One Bulk Fill Restorative—FIL; SDR Plus Bulk Fill Flowable—SDR). Three-point bending (n = 10) was used to measure flexural strength (FS) and flexural modulus (FM). In the 3 s group, two 2 mm thick specimens were stacked to obtain 4 mm thickness, while 2 mm-thick specimens were used for ISO group. Specimens were aged for 1, 30, or 30 + 3 days in ethanol. The degree of conversion (DC) up to 4 mm was measured by Raman spectroscopy. There was no difference between curing protocols in FS after 1 day for all materials except PFLW. FM was higher for all materials for ISO curing protocol. Mechanical properties deteriorated by increasing depth (2–4 mm) and aging. ISO curing induced higher DC for PFLW and FIL, while 3 s curing was sufficient for PFILL and SDR. The 3 s curing negatively affected FM of all tested materials, whereas its influence on FS and DC was highly material-specific.

Influence of Light-polymerization Modes on the Degree of Conversion and Mechanical Properties of Resin Composites: A Comparative Analysis Between a Hybrid and a Nanofilled Composite

10.2341/07-81 ◽  
2008 ◽  
Vol 33 (3) ◽  
pp. 287-293 ◽  
Author(s):  
E. M. da Silva ◽  
L. T. Poskus ◽  
J. G. A. Guimarães
Keyword(s):  
Mechanical Properties ◽  
Comparative Analysis ◽  
Flexural Strength ◽  
Hybrid Composite ◽  
Clinical Relevance ◽  
Flexural Modulus ◽  
Degree Of Conversion ◽  
The Other ◽  
Lower Degree ◽  
Resin Composites

Clinical Relevance The nanofilled composite presented a lower degree of conversion, flexural modulus and flexural strength than the hybrid composite. On the other hand, the two materials had a similar hardness. The light polymerization mode influenced only the degree of conversion and the hardness of composites.

Properties of a New Nanofiber Restorative Composite

2019 ◽  
Vol 44 (1) ◽  
pp. 34-41 ◽  
Author(s):  
EM Yancey ◽  
W Lien ◽  
CS Nuttall ◽  
JA Brewster ◽  
HW Roberts ◽  
...  
Keyword(s):  
Flexural Strength ◽  
Hybrid Composites ◽  
Flexural Modulus ◽  
Testing Machine ◽  
Degree Of Conversion ◽  
Imaging Device ◽  
Polymerization Shrinkage ◽  
Depth Of Cure ◽  
Curing Shrinkage ◽  
Cylindrical Mold

SUMMARY A new nanofiber-reinforced hybrid composite (NovaPro Fill, Nanova) was recently introduced with reportedly improved mechanical properties. The purpose of this study was to compare the properties (flexural strength/modulus, degree of conversion [DC], depth of cure, and polymerization shrinkage) of the nanofiber composite to those of traditional hybrid composites (Filtek Z250, 3M ESPE; Esthet-X HD, Dentsply). To determine flexural strength and modulus, composite was placed in a rectangular mold, light-cured, stored for 24 hours, and then fractured in a universal testing machine. For degree of conversion, composite was placed in a cylindrical mold, light-cured, and stored for 24 hours. Measurements were made at the top and bottom surfaces using Fourier Transform Infrared Spectroscopy. To determine depth of cure, composite was placed in a cylindrical mold and light-cured. Uncured composite was scraped until polymerized resin was reached. Remaining composite was measured and divided by two. Polymerization shrinkage was determined by placing the composite material on a pedestal in a video-imaging device while light-curing. Shrinkage was determined after 10 minutes. Data were analyzed with one-way analysis of variance and Tukey post hoc test per property (α=0.05). Compared to Filtek Z250, NovaPro Fill had significantly lower flexural strength and modulus, greater volumetric shrinkage, and similar depth of cure, but greater top and bottom DC. Compared to Esthet-X HD, NovaPro Fill had similar flexural strength, shrinkage, and top and bottom DC, but significantly greater depth of cure and flexural modulus.

Flexural strength and flexural modulus of urethane resin-based resin composites

2018 ◽  
Vol 34 ◽  
pp. e31
Author(s):  
A.B. Correr ◽  
J.P. Curtulo ◽  
M.A.C. Sinhoreti ◽  
L. Correr-Sobrinho
Keyword(s):  
Flexural Strength ◽  
Flexural Modulus ◽  
Resin Composites

scholarly journals Influence of a Repeated Preheating Procedure on Mechanical Properties of Three Resin Composites

2015 ◽  
Vol 40 (2) ◽  
pp. 181-189 ◽  
Author(s):  
M D'Amario ◽  
F De Angelis ◽  
M Vadini ◽  
N Marchili ◽  
S Mummolo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Vickers Microhardness ◽  
Flexural Modulus ◽  
Bending Test ◽  
Resin Composites ◽  
Three Point Bending ◽  
Main Effect ◽  
Dependent Variables ◽  
Marginal Means

SUMMARY The aim of this study was to assess the flexural strength, flexural elastic modulus and Vickers microhardness of three resin composites prepared at room temperature or cured after one or repeated preheating cycles to a temperature of 39°C. Three resin composites were evaluated: Enamel Plus HFO (Micerium), Opallis (FGM), and Ceram X Duo (Dentsply DeTrey). For each trial, one group of specimens of each material was fabricated under ambient laboratory conditions, whereas in the other groups, the composites were cured after 1, 10, 20, 30, or 40 preheating cycles to a temperature of 39°C in a preheating device. Ten rectangular prismatic specimens (25 × 2 × 2 mm) were prepared for each group (N=180; n=10) and subjected to a three-point bending test for flexural strength and flexural modulus evaluation. Vickers microhardness was assessed on 10 cylindrical specimens from each group (N=180; n=10). Statistical analysis showed that, regardless of the material, the number of heating cycles was not a significant factor and was unable to influence the three mechanical properties tested. However, a significant main effect of the employed material on the marginal means of the three dependent variables was detected.

scholarly journals Monomers used in resin composites: degree of conversion, mechanical properties and water sorption/solubility

2012 ◽  
Vol 23 (5) ◽  
pp. 508-514 ◽  
Author(s):  
Vinícius E. S. Gajewski ◽  
Carmem S. Pfeifer ◽  
Nívea R. G. Fróes-Salgado ◽  
Letícia C. C. Boaro ◽  
Roberto R. Braga
Keyword(s):  
Mechanical Properties ◽  
Water Sorption ◽  
Flexural Modulus ◽  
Triethylene Glycol ◽  
Degree Of Conversion ◽  
Resin Composites ◽  
Triethylene Glycol Dimethacrylate ◽  
Three Point Bending ◽  
Rate Of Polymerization ◽  
Urethane Dimethacrylate

The organic phase of resin composites is constituted by dimethacrylate resins, the most common monomers being the bisphenol A diglycidildimethacrylate (BisGMA), its ethoxylated version (BisEMA), triethylene glycol dimethacrylate (TEGDMA) and urethane dimethacrylate (UDMA). This study compared the homopolymers formed from the monomers used in restorative dental composites in terms of their degree of conversion (DC) and reaction kinetics (by near infra-red spectroscopy, n=3), mechanical properties (flexural modulus and strength in three point-bending, FM and FS, respectively, n=15), water sorption and solubility (WS and SL, respectively - ISO 4049, n=5). Materials were made photopolymerizable by the addition of camphoroquinone/dimethylamine ethyl methacrylate. TEGDMA showed the highest DC, followed by BisEMA, UDMA and BisGMA, both at 10 min and at 24h (p<0.001). UDMA showed the highest rate of polymerization, followed by TEGDMA, BisEMA and BisGMA (H0=13.254, p<0.001). UDMA and TEGDMA presented similar FM, significantly higher (p<0.001) than BisEMA and BisGMA, which in turn present statistically similar values (p>0.001). For FS, UDMA presented the highest value (p<0.001), followed by TEGDMA, then by BisEMA and BisGMA, which were statistically similar (p>0.001). BisGMA showed the highest WS, and TEGDMA and BisEMA the lowest. UDMA was statistically similar to all (H0=16.074, p<0.001). TEGDMA presented the highest SL, followed by UDMA, BisGMA and BisEMA (p<0.001). The tested homopolymers presented different behaviors in terms of polymerization kinetics, flexural properties, water sorption and solubility. Therefore, the use of copolymers is justified in order to obtain high DC and mechanical properties, as well as good resistance to water degradation.

scholarly journals Influence of Filler Loading on the Mechanical Properties of Flowable Resin Composites

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1477 ◽  
Author(s):  
Ioana-Codruţa Mirică ◽  
Gabriel Furtos ◽  
Bogdan Bâldea ◽  
Ondine Lucaciu ◽  
Aranka Ilea ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Flexural Strength ◽  
Flexural Modulus ◽  
Filler Loading ◽  
The Other ◽  
Inorganic Filler ◽  
Resin Composites ◽  
Homogeneous Type ◽  
Sem Images

The aim of this study was to evaluate the correlation between the percent of inorganic filler by weight (wt. %) and by volume (vol. %) of 11 flowable resin composites (FRCs) and their mechanical properties. To establish the correlation, the quantity of inorganic filler was determined by combustion and shape/size analyzed by SEM images. The compressive strength (CS), flexural strength (FS), and flexural modulus (FM) were determined. The CS values were between 182.87-310.38 MPa, the FS values ranged between 59.59 and 96.95 MPa, and the FM values were between 2.34 and 6.23 GPa. The percentage of inorganic filler registered values situated between 52.25 and 69.64 wt. % and 35.35 and 53.50 vol. %. There was a very good correlation between CS, FS, and FM vs. the inorganic filler by wt. % and vol. %. (R2 = 0.8899–0.9483). The highest regression was obtained for the FM values vs. vol. %. SEM images of the tested FRCs showed hybrid inorganic filler for Filtek Supreme XT (A3) and StarFlow (A2) and a homogeneous type of inorganic filler for the other investigated materials. All of the FS values were above 50 MPa, the ISO 4049/2019 limit for FRCs.

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.

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