scholarly journals Characterization of Experimental Short-Fiber-Reinforced Dual-Cure Core Build-Up Resin Composites

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2281
Author(s):  
Eija Säilynoja ◽  
Sufyan Garoushi ◽  
Pekka K. Vallittu ◽  
Lippo Lassila

As a core build-up material, dual-cured (DC) resin-based composites are becoming popular. The aim of this research was to investigate specific physical and handling properties of new experimental short-fiber-reinforced DC resin composites (SFRCs) in comparison to different commercial, conventional DC materials (e.g., Gradia Core, Rebilda DC, LuxaCore Z, and Visalys® CemCore). Degree of monomer conversion (DC%) was determined by FTIR-spectrometry using either self- or light-curing mode. The flexural strength, modulus, and fracture toughness were calculated through a three-point bending setup. Viscosity was analyzed at room (22 °C) and mouth (35 °C) temperatures with a rotating disk rheometer. The surface microstructure of each resin composite was examined with scanning electron microscopy (SEM). Data were statistically analyzed with analysis of variance ANOVA (p = 0.05). The curing mode showed significant (p < 0.05) effect on the DC% and flexural properties of tested DC resin composites and differences were material dependent. SFRC exhibited the highest fracture toughness (2.3 MPa m1/2) values and LuxaCore showed the lowest values (1 MPa m1/2) among the tested materials (p < 0.05). After light curing, Gradia Core and SFRCs showed the highest flexural properties (p < 0.05), while the other resin composites had comparable values. The novel DC short-fiber-reinforced core build-up resin composite demonstrated super fracture toughness compared to the tested DC conventional resin composites.

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4919
Author(s):  
Wojciech Grzebieluch ◽  
Piotr Kowalewski ◽  
Dominika Grygier ◽  
Małgorzata Rutkowska-Gorczyca ◽  
Marcin Kozakiewicz ◽  
...  

Thanks to the continuous development of light-curing resin composites it is now possible to print permanent single-tooth restorations. The purpose of this study was to compare resin composites for milling -Gandio Blocks(GR), Brilliant Crios(CR) and Enamic(EN) with resin composite for 3D printing—VarseoSmileCrown plus(VSC). Three-point bending was used to measure flexural strength (σf) and flexural modulus (Ef). The microhardness was measured using a Vickers method, while fractographic, microstructural, texture and fractal dimension (FD) analyses were performed using SEM, optical microscope and picture analysis methods. The values of σf ranged from 118.96 (±2.81) MPa for EN to 186.02 (±10.49) MPa for GR, and the values of Ef ranged from 4.37 (±0.8) GPa for VSC to 28.55 (±0.34) GPa for EN. HV01 ranged from 25.8 (±0.7) for VSC to 273.42 (±27.11) for EN. The filler content ranged from 19–24 vol. % for VSC to 70–80 vol. % for GR and EN. The observed fractures are typical for brittle materials. The correlation between FD of materials microstructure and Ef was observed. σf of the printed resin depends on layers orientation and is significantly lower than σf of GR and CR. Ef of the printed material is significantly lower than Ef of blocks for milling.


2018 ◽  
Vol 9 ◽  
pp. 158
Author(s):  
Ellyza Herda ◽  
Nadia Safira Ninda ◽  
Mia Damiyanti

Objective: This study aimed to identify post-cure’s effect on the depth of cure (DOC) of a short fiber-reinforced resin composite (SFRC).Methods: Six EverX PosteriorTM shade A3 specimens were cured with a light-emitting diode light curing unit with 800 mW/cm2 of light irradiation for 20 s. The specimens were divided into two groups. The first was measured immediately post-cure and the second was measured 24-h post-cure. They were measured with a Vickers microhardness profile test. An independent t-test was used to analyze the significance of the differences between the DOC value and different variables.Results: The DOC of the specimens measured immediately post-cure was 3.02±0.02 mm. The DOC of the specimens measured 24-h post-cure was 3.93±0.03 mm.Conclusion: The DOC of the specimens measured 24-h post-cure was significantly higher than the DOC of the specimens measured immediately post-cure. Post-cure polymerization (24-h post-cure) can increase the DOC values of an SFRC.


2018 ◽  
Vol 9 ◽  
pp. 155
Author(s):  
Ellyza Herda ◽  
Nabila . ◽  
Bambang Irawan

Objective: This study aimed to identify the shear bond strength of two different restorative particulate resin composites with a short fiber-reinforced resin composite (SFRC) substructure.Methods: Two restorative particulate resin composites, G-aenial PosteriorTM (Group A, 10 specimens) and Tetric N-Ceramtm (Group B, 10 specimens), were used as an upper layer of everX posteriorTM, an SFRC. A shear bond strength test was performed using a universal testing machine with a load of 100 kgf and a crosshead speed of 0.5 mm/min. The data were analyzed statistically using the independent samples t-test.Results: The mean shear bond strength values were found to be18.64±1.5 MPa (Group A) and 22.05±1.8 MPa (Group B). A significant difference in shear bond strength between the two groups was found.Conclusion: The shear bond strength value is higher in the Tetric N-CeramTM restorative particulate resin composite with SFRC as a substructure than the G-aenial PosteriorTM restorative particulate resin composite.


2016 ◽  
Vol 35 (3) ◽  
pp. 418-424 ◽  
Author(s):  
Akimasa TSUJIMOTO ◽  
Wayne W. BARKMEIER ◽  
Toshiki TAKAMIZAWA ◽  
Mark A. LATTA ◽  
Masashi MIYAZAKI

2021 ◽  
Author(s):  
K Mizutani ◽  
R Ishii ◽  
T Takamizawa ◽  
S Shibasaki ◽  
H Kurokawa ◽  
...  

SUMMARY Objective: The aim of this study was to determine the flexural properties and surface characteristics of a structural colored resin composite after different finishing and polishing methods, in comparison to those of conventional resin composites. Methods and Materials: A structural color resin composite, Omnichroma (OM, Tokuyama Corp, Chiyoda City, Tokyo, Japan), and two comparison resin composites, Filtek Supreme Ultra (FS, 3M, St Paul, MN, USA) and Tetric EvoCeram (TE, Ivoclar Vivadent, Schaan, Liechtenstein), were used. The flexural properties of the resin composites were determined in accordance with the ISO 4049 specifications. For surface properties, 70 polymerized specimens of each resin composite were prepared and divided into seven groups of 10. Surface roughness (Sa), gloss (GU), and surface free energy (SFE) were investigated after the following finishing and polishing methods. Three groups of specimens were finished with a superfine-grit diamond bur (SFD), and three with a tungsten carbide bur (TCB). After finishing, one of the two remaining groups was polished with a one-step silicone point (CMP), and the other with an aluminum oxide flexible disk (SSD). A group ground with SiC 320-grit was set as a baseline. Results: The average flexural strength ranged from 116.6 to 142.3 MPa in the following order with significant differences between each value: FS &gt; TE &gt; OM. The average E ranged from 6.8 to 13.2 GPa in the following order with significant differences between each value: FS &gt; TE &gt; OM. The average R ranged from 0.77 to 1.01 MJ/mm3 in the following order: OM &gt; FS &gt; TE. The Sa values of the OM groups polished with CMP and SSD were found to be significantly lower than those of the other resin composites, regardless of the finishing method. The GU values appeared to be dependent on the material and the finishing method used. The OM specimens polished with SSD showed significantly higher GU values than those polished with CMP. Most of the resin composites polished with SSD demonstrated significantly higher γS values compared to the other groups. Extremely strong negative correlations between Sa and GU in the combined data from the three resin composites and each resin composite and between Sa and γS in the OM specimens were observed; GU showed a strong positive correlation with γS in the same material. Conclusion: These findings indicate that both flexural and surface properties are material dependent. Furthermore, the different finishing and polishing methods used in this study were observed to affect the Sa, GU, and SFE of the resin composites.


2009 ◽  
Vol 79 (3) ◽  
pp. 546-550 ◽  
Author(s):  
Makiha Shinya ◽  
Akikazu Shinya ◽  
Lippo V. J. Lassila ◽  
Juha Varrela ◽  
Pekka K. Vallittu

Abstract Objective: To test the hypothesis that there is no difference in the degree of conversion (DC%) of orthodontic composites during the light-curing process with or without the use of a glass-fiber reinforcement. Materials and Methods: Two light-curing orthodontic adhesives, Transbond XT (TB) and Beauty Ortho Bond (BO), were used with woven preimpregnated glass fibers. The degree of monomer conversion was determined for both adhesives in three settings (n = 5 per group): in the first group, the adhesive was cured without a bracket (control); in the second group, the bracket was bonded using adhesive without fiber reinforcement; and in the third group, a layer of glass-fiber net was added between the bracket and resin. The adhesive resin was light cured, and the DC% was determined by Fourier transform infrared spectroscopy. Results: A two-way analysis of variance revealed significant differences in the DC% (P &lt; .001) between adhesives and between the fiber-reinforced and nonreinforced groups. When the nonreinforced adhesives were light cured under the brackets, the DC% was significantly lower (TB: 37.0%, SD 3.4; BO: 36.9%, SD 1.9) compared with the control (TB: 54.7%, SD 0.6; BO: 65.9%, SD 0.5). A higher DC% was found when the resin was light cured in the presence of a glass-fiber net (TB: 44.1%, SD 0.3; BO: 55.3%, SD 1.7). Conclusion: The hypothesis is rejected. The degree of monomer conversion of the light-curing adhesive resin under stainless steel bracket can be improved by adding a thin layer of glass-fiber–reinforced composite between the bracket and adhesive resin.


2004 ◽  
Vol 5 (2) ◽  
pp. 14-26 ◽  
Author(s):  
Lippo V.J. Lassila ◽  
Pekka K. Vallittu

Abstract The aim of this study was to investigate the influence of the position of the fiber rich layer on the flexural properties of fiber-reinforced composite (FRC) construction. In addition, the total residual monomer content of FRC was quantitatively determined to find out the difference of the effectiveness of two types of light-curing units using liquid chromatography (HPLC). Unidirectional continuous E-glass FRC and hybrid particulate filler composite resins were used in the fabrication of test specimens. Four different positions of the FRC layer were used: compression, neutral, tension, and vertical side position. A three-point bending test (ISO 10477) was performed to measure the flexural properties of the specimens. Position of the FRC layer had a significant effect on the flexural strength (p<0.001, ANOVA). Also, the type of light-curing device had an effect on flexural strength (p<0.001). Specimens with FRC positioned on the compression side showed flexural strength of approximately 250 MPa, whereas FRC positioned on the tension side showed strength ranging from 500 to 600 MPa. Mean flexural modulus with FRC placed horizontally ranged between 9-12 GPa; no significant difference was found between these groups. However when fiber reinforcement was positioned vertically, the flexural modulus raised up to 16 GPa. Specimens with 24 vol% glass fibers contained 52% less residual monomer than specimens without glass fibers. The monomer content was lower in specimens polymerized with the curing device with higher polymerization temperature. In order to optimize flexural strength of low fiber volume fraction, the fibers should be placed at the tension side of the specimen. Citation Lassila LVJ, Vallittu PK. The Effect of Fiber Position and Polymerization Condition on the Flexural Properties of Fiber-Reinforced Composite. J Contemp Dent Pract 2004 May;(5)2:014-026.


2003 ◽  
Vol 17 (08n09) ◽  
pp. 1827-1832
Author(s):  
Moon Sik Han ◽  
Jung Il Song

Evaluation of fracture toughness of short fiber reinforced metal matrix composites (MMCs) becomes important for the application as structural materials. Therefore, in this study static and dynamic fracture toughness of MMCs manufactured by squeeze casting process were investigated. A number of MMCs have been tested with various matrix alloys, volume fractions, and specifically types of reinforcements. It was found that static and dynamic fracture toughness of metal matrix composites was remarkably decreased by the addition of ceramic reinforcements. Dynamic fracture toughness slightly decreased compared with static fracture toughness because of the effect of dynamic velocity under impact loading. The toughness of ceramic reinforced MMCs is controlled by a complexity interaction between the matrix alloy and reinforcement. Important properties which influence toughness include the type of reinforcement (its physical form, size), volume fraction and combination of reinforcement, and the matrix alloy. And notch fracture toughness of MMCs for simple evaluation was also discussed.


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