scholarly journals Post-cure heat treatments influence on mechanical and optical properties of resin composites

2021 ◽  
Vol 32 (4) ◽  
pp. 96-105
Author(s):  
Vitor de Oliveira Baldo ◽  
Marlus da Silva Pedrosa ◽  
Igor Studart Medeiros
Keyword(s):  
Heat Treatment ◽  
Optical Properties ◽  
Room Temperature ◽  
Red Wine ◽  
Contrast Ratio ◽  
Degree Of Conversion ◽  
Control Group ◽  
Resin Composites ◽  
Color Changes ◽  
Knoop Microhardness

Abstract This study evaluated the effect of post-cure heat treatment (PCHT) on the Knoop microhardness (KHN), degree of conversion (DC), color changes, and contrast ratio (CR) of four resin composites (RCs): Z100 (3M ESPE), Z350 XT (3M ESPE), Estelite Omega (Tokuyama) and Empress Direct (Ivoclar Vivadent). Specimens (12 × 1 mm) were prepared for each material (n = 10 / group). After curing, samples were subjected to PCHT for 10 min at 100°C or 170°C. Control group was maintained at room temperature (24°C) for the same time. The DC was analyzed by FT-NIR immediately and 24 h after the PCHT (n = 3 / group). KHN was analyzed 24 h after PCHT (n = 10 / group). According to CIEDE2000 (∆E00), color measurements were obtained immediately after curing, five minutes after PCHT, and after seven days of storage in water, coffee, and red wine. Data were analyzed by One and Two-Way ANOVA (p < 0.05). Z100, Z350, and Estelite Omega showed increases in KHN with increased temperature (p < 0.05). PCHT at 100°C and 170°C led to a higher DC of all RCs (p < 0.05). Initially, the PCHT lead to increased ∆E00 values (p < 0.05), which was decreased after immersion in coffee and wine (p < 0.05). Considering the effect of PCHT and staining solutions, lower color changes were observed in the thermally treated specimens (p < 0.05). Taken collectively, the results suggest the PCHT as an economical and practical alternative to enhance direct RC's properties in direct-indirect and indirect restorations.

scholarly journals Shear Bond Strength and Optical Properties of Resin Composite - Layered Provisional Poly(methyl methacrylate) (PMMA)

2021 ◽  
Vol 15 (1) ◽  
pp. 176-183
Author(s):  
Juthatip Aksornmuang ◽  
Juckrapun Tiangtrong
Keyword(s):  
Optical Properties ◽  
Bond Strength ◽  
Methyl Methacrylate ◽  
Shear Bond Strength ◽  
Resin Composite ◽  
Bonding Agent ◽  
Control Group ◽  
Resin Composites ◽  
Poly Methyl Methacrylate ◽  
Pmma Surface

Aims: To compare the shear bond strength between resin composite and Poly(methyl methacrylate) (PMMA) with various bonding protocols and to evaluate the optical properties of resin composite - layered provisional Poly(methyl methacrylate) (PMMA). Materials and Methods: Eighty cylindrical shape specimens were fabricated from self-polymerized provisional Poly(methyl methacrylate) (PMMA) and they were randomly divided into eight groups. Poly(methyl methacrylate) (PMMA) was mixed and bonded onto the specimens as a positive control group. Resin composite was bonded to MMA-wetted surface without bonding agent as a negative control group. All remaining groups were bonded to resin composite using different bonding agents (Scothbond Universal, Luxatemp glaze&bond, and HC Primer) with and without MMA wetting. Shear bond strength testing was performed using a universal testing machine. Various shades of 0.5 mm-thick resin composites were layered onto 1.5 mm-thick PMMA both light and dark shade, with the most effective bonding protocol. Color differences between resin composite and – layered provisional Poly(methyl methacrylate) (PMMA) were measured using Spectrophotometer. Results: Bonding resin composite onto Poly(methyl methacrylate) (PMMA) using luxatemp glaze, bond and HC Primer without methyl methacrylate wetting provided statistically significantly lower bond strength than those of the MMA-wetted Poly(methyl methacrylate) (PMMA) surface. The highest shear bond strength was achieved with the application of Scothbond Universal Adhesive regardless of MMA wetting. The colors of resin composite - layered provisional Poly(methyl methacrylate) (PMMA) were different from the original resin composite color with ΔE results greater than the acceptable threshold (>3.7). Conclusion: Resin composites were able to effectively bond to the MMA-wetted Poly(methyl methacrylate) (PMMA) surface with the application of a tested bonding agent. Layering Poly(methyl methacrylate) (PMMA) with 0.5 mm-thick resin composite could not modify the Poly(methyl methacrylate) (PMMA) shade to the original resin composite color.

scholarly journals Effect of 4-(N,N-dimethylamino)phenethyl Alcohol on Degree of Conversion and Cytotoxicity of Photo-Polymerized CQ-Based Resin Composites

2014 ◽  
Vol 25 (6) ◽  
pp. 538-542 ◽  
Author(s):  
Dayane Carvalho Ramos Salles de Oliveira ◽  
Camila Batista da Silva ◽  
Bruno Vilela Muniz ◽  
Maria C. Volpato ◽  
Ana Rosa Costa ◽  
...  
Keyword(s):  
Organic Matrix ◽  
Human Keratinocytes ◽  
Filler Loading ◽  
Degree Of Conversion ◽  
Control Group ◽  
Resin Composites ◽  
Cytotoxic Effects ◽  
Phenethyl Alcohol ◽  
Significant Difference ◽  
Post Hoc

The aim of this study was to evaluate the degree of conversion (DC) and the cytotoxicity of photo-cured experimental resin composites containing 4-(N,N-dimethylamino)phenethyl alcohol (DMPOH) combined to the camphorquinone (CQ) compared with ethylamine benzoate (EDAB). The resin composites were mechanically blended using 35 wt% of an organic matrix and 65 wt% of filler loading. To this matrix was added 0.2 wt% of CQ and 0.2 wt% of one of the reducing agents tested. 5x1 mm samples (n=5) were previously submitted to DC measurement and then pre-immersed in complete culture medium without 10% (v/v) bovine serum for 1 h or 24 h at 37 °C in a humidifier incubator with 5% CO2 and 95% humidity to evaluate the cytotoxic effects of experimental resin composites using the MTT assay on immortalized human keratinocytes cells. As a result of absence of normal distribution, the statistical analysis was performed using the nonparametric Kruskal-Wallis to evaluate the cytotoxicity and one-way analysis of variance to evaluate the DC. For multiple comparisons, cytotoxicity statistical analyses were submitted to Student-Newman-Keuls and DC analysis to Tukey's HSD post-hoc test (=0.05). No significant differences were found between the DC of DMPOH (49.9%) and EDAB (50.7%). 1 h outcomes showed no significant difference of the cell viability between EDAB (99.26%), DMPOH (94.85%) and the control group (100%). After 24 h no significant difference were found between EDAB (48.44%) and DMPOH (38.06%), but significant difference was found compared with the control group (p>0.05). DMPOH presented similar DC and cytotoxicity compared with EDAB when associated with CQ.

scholarly journals Influence of the heat treatment on the color of ground pepper (Capsicum annuum)

2007 ◽  
pp. 53-58 ◽  
Author(s):  
Ljubo Vracar ◽  
Aleksandra Tepic ◽  
Biserka Vujicic ◽  
Srdjan Solaja
Keyword(s):  
Heat Treatment ◽  
Capsicum Annuum ◽  
Room Temperature ◽  
Carotenoid Content ◽  
Surface Color ◽  
Qualitative And Quantitative ◽  
Color Changes ◽  
The World ◽  
Color Deterioration ◽  
Microbiological Status

Red pepper (Capsicum annuum L.) is one of the most important vegetables in the world. The main ground pepper quality attributes are extractable color, surface color, qualitative and quantitative carotenoid content. In this work, the influence of heat treatment on ground pepper quality was investigated. Microbiological status was examined in non-sterilized and sterilized ground pepper. Color changes were assessed by measuring the extractable color (ASTA) and surface color, using a photocolorimeter. The obtained results showed that at the end of experiment, non-sterilized samples had higher color values in comparison to the sterilized ones. Also, color deterioration was heightened at room temperature.

scholarly journals Tuning Green to Red Color in Erbium Niobate Micro- and Nanoparticles

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 660
Author(s):  
Susana Devesa ◽  
Joana Rodrigues ◽  
Sílvia Soreto Teixeira ◽  
Aidan P. Rooney ◽  
Manuel P. F. Graça ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Optical Properties ◽  
Room Temperature ◽  
Sol Gel ◽  
High Energy ◽  
Site Symmetry ◽  
Photoluminescence Spectra ◽  
Heat Treated ◽  
Red Color ◽  
Optical Activation

Tetragonal Er0.5Nb0.5O2 and monoclinic ErNbO4 micro- and nanoparticles were prepared by the citrate sol–gel method and heat-treated at temperatures between 700 and 1600 °C. ErNbO4 revealed a spherical-shaped crystallite, whose size increased with heat treatment temperatures. To assess their optical properties at room temperature (RT), a thorough spectroscopic study was conducted. RT photoluminescence (PL) spectroscopy revealed that Er3+ optical activation was achieved in all samples. The photoluminescence spectra show the green/yellow 2H11/2, 4S3/2→4I15/2 and red 4F9/2→4I15/2 intraionic transitions as the main visible recombination, with the number of the crystal field splitting Er3+ multiplets reflecting the ion site symmetry in the crystalline phases. PL excitation allows the identification of Er3+ high-energy excited multiplets as the preferential population paths of the emitting levels. Independently of the crystalline structure, the intensity ratio between the green/yellow and red intraionic transitions was found to be strongly sensitive to the excitation energy. After pumping the samples with a resonant excitation into the 4G11/2 excited multiplet, a green/yellow transition stronger than the red one was observed, whereas the reverse occurred for higher excitation photon energies. Thus, a controllable selective excited tunable green to red color was achieved, which endows new opportunities for photonic and optoelectronic applications.

Effect of Bleaching on Color Change of Stained Resin Composites

2017 ◽  
Vol 751 ◽  
pp. 636-642
Author(s):  
Ratcha Raksakmanut ◽  
Ampaporn Nithipratheep ◽  
Ornjira Weeriyanan ◽  
Panida Pittayaporn ◽  
Waivich Komonpale ◽  
...  
Keyword(s):  
Red Wine ◽  
Color Change ◽  
Artificial Saliva ◽  
Resin Composites ◽  
Carbamide Peroxide ◽  
Spectrophotometric Measurement ◽  
Bleaching Process ◽  
Color Changes ◽  
Color Differences ◽  
Before And After

The aim of this study was to evaluate the effects of bleaching on color change of stained resin composites. Ninety disk-shaped specimens were prepared with 3 different composite materials (Estelite ∑ Quick, Premise, and Filtek Z350 XT). After stored in artificial saliva at 37°C for 24 hours in an incubator, the 30 specimens of each material were divided into 3 subgroups and immersed in either coffee, red wine, or artificial saliva (control) at 37°C. After 24 days, spectrophotometric measurement was performed. After the staining process, the bleaching agent (Opalescence, 10% carbamide peroxide) was applied to the surface of the specimens, 8 hours per day for 14 days. After the bleaching process, spectrophotometric measurement was performed. The color differences between specimens before and after bleaching were statistically significant (ΔE*ab>3.3) for all composites in the red wine staining. The highest-level color change after bleaching was observed for Filtek Z350 XT in red wine staining, while the least value was found in Estelite ∑ Quick in coffee staining. In summary, color changes of all red wine-stained composites after bleaching were noticeable and have higher level of color change than coffee-stained composites.

scholarly journals Evaluation of Some Exogenous Colorants Effects on Resin Based Materials Used in Incipient Caries Lesions Therapy

2019 ◽  
Vol 56 (3) ◽  
pp. 629-634
Author(s):  
Ionut Taraboanta ◽  
Galina Pancu ◽  
Cristina Angela Ghiorghe ◽  
Claudiu Topoliceanu ◽  
Irina Nica ◽  
...  
Keyword(s):  
Cigarette Smoke ◽  
Red Wine ◽  
Color Variation ◽  
Control Group ◽  
Color Changes ◽  
Combined Action ◽  
Incipient Caries ◽  
Materials Used ◽  
The Moment ◽  
Caries Lesions

The aim of this study was to evaluate the potential of coloring of two commercial beverages: coffee and wine, and cigarette smoke, on three materials (ICON infiltration resin, MI Varnish Recaldent, and a sealant based on composite resin) currently used in incipient caries therapy. The study group included 75 extracted teeth that were divided into 3 groups corresponding to each material used. The groups were divided into 5 subgroups that corresponded to each colorant (A. red wine, B. coffee, C. cigarette smoke, D. association of the three colorants, E. control group). The coloration degree of the samples was measured both after the moment of coloring (M3) and after polishing (M4). The results showed a significant increase of the coloring degree for the samples subjected to the combined action of the three colorants (M3), for all the three materials used (DE1*: Id = 23.56, IId = 25.87, IIId = 19.87), and in terms of the coloring degree after the polishing procedure (M4), a decrease of the values was observed (DE2*: Id = 17.56, IId = 21.67, IIId = 16.78). In conclusion, both exposure to the two beverages used in the study and cigarette smoke (C) leads to the appearance of color changes, but the most significant changes were obtained by combining the three colorants (D). Also, the polishing procedure leaded to an improvement of the color variation for all three materials.

scholarly journals Study the Effect of heat treatment on AgInTe2 the optical properties thin films

2019 ◽  
Vol 24 (3) ◽  
pp. 95
Author(s):  
Marwan R. Abass ◽  
Iman H. Khudayer
Keyword(s):  
Thin Films ◽  
Heat Treatment ◽  
Dielectric Constant ◽  
Optical Properties ◽  
Room Temperature ◽  
Thermal Evaporation ◽  
Transmission Spectra ◽  
Vacuum Thermal Evaporation ◽  
Photovoltaic Applications ◽  
Temperature And Pressure

AgInTe2 (AIT) thin films had been prepared by the used technique of vacuum thermal evaporation, with thickness  300 nm, the deposition rate  1.7 ±0.1 nm/sec on a glass substrate at room temperature and pressure (10-5) mbar Heat treatment was performed in the range (473-673) K for samples. The AIT thin films optical properties (absorption coefficient, index of refractive, extinction coefficient, real and imaginary dielectric constant) were studied by determination using measurement absorption and transmission spectra. The results showed they are wide applications such as photovoltaic electronic applications and photovoltaic applications.   http://dx.doi.org/10.25130/tjps.24.2019.053   

scholarly journals Polymorphic gallium for active resonance tuning in photonic nanostructures: from bulk gallium to two-dimensional (2D) gallenene

Nanophotonics ◽  
2020 ◽  
Vol 9 (14) ◽  
pp. 4233-4252
Author(s):  
Yael Gutiérrez ◽  
Pablo García-Fernández ◽  
Javier Junquera ◽  
April S. Brown ◽  
Fernando Moreno ◽  
...  
Keyword(s):  
Optical Properties ◽  
Room Temperature ◽  
Phase Change Materials ◽  
Two Dimensional ◽  
Active Materials ◽  
Promising Candidate ◽  
Plasmonic Structures ◽  
Resonance Tuning ◽  
The Many ◽  
Optical Behavior

AbstractReconfigurable plasmonics is driving an extensive quest for active materials that can support a controllable modulation of their optical properties for dynamically tunable plasmonic structures. Here, polymorphic gallium (Ga) is demonstrated to be a very promising candidate for adaptive plasmonics and reconfigurable photonics applications. The Ga sp-metal is widely known as a liquid metal at room temperature. In addition to the many other compelling attributes of nanostructured Ga, including minimal oxidation and biocompatibility, its six phases have varying degrees of metallic character, providing a wide gamut of electrical conductivity and optical behavior tunability. Here, the dielectric function of the several Ga phases is introduced and correlated with their respective electronic structures. The key conditions for optimal optical modulation and switching for each Ga phase are evaluated. Additionally, we provide a comparison of Ga with other more common phase-change materials, showing better performance of Ga at optical frequencies. Furthermore, we first report, to the best of our knowledge, the optical properties of liquid Ga in the terahertz (THz) range showing its broad plasmonic tunability from ultraviolet to visible-infrared and down to the THz regime. Finally, we provide both computational and experimental evidence of extension of Ga polymorphism to bidimensional two-dimensional (2D) gallenene, paving the way to new bidimensional reconfigurable plasmonic platforms.

Effect of gamma radiation on the structural, thermal and optical properties of PMMA/Sn0.75Fe0.25S2 nanocomposite

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Ali A. Alhazime ◽  
Nesreen T. El-Shamy ◽  
Kaoutar Benthami ◽  
Mai ME. Barakat ◽  
Samir A. Nouh
Keyword(s):  
Thermal Stability ◽  
Optical Properties ◽  
Gamma Irradiation ◽  
Optical Band Gap ◽  
Color Variation ◽  
Nanocomposite Films ◽  
Color Changes ◽  
Gamma Irradiated ◽  
Intermolecular Crosslinking ◽  
Amorphous Part

AbstractNanocomposite films of polymethylmethacrylate PMMA with Sn0.75Fe0.25S2 nanoparticles (NPs) were fabricated by both thermolysis and casting techniques. Changes in PMMA/Sn0.75Fe0.25S2 nanocomposite (NCP) due to gamma irradiation have been measured. XRD results indicate that the gamma doses of 10–80 kGy cause intermolecular crosslinking that reduces the ordered portion in the NPs. Bonding between the NPs and the host PMMA was confirmed by FTIR. TGA results indicate an enhancement in thermal stability in the NCP films irradiated with doses 20–80 kGy. The optical band gap was reduced from 3.23 to 2.47 eV upon gamma irradiation up to 80 kGy due bonding between the NPs and PMMA which enhanced the amorphous part of the NPs. Finally, the color variation between the blank and irradiated films (ΔE) was determined. Color changes immensely when the PMMA/Sn0.75Fe0.25S2 NCP films are gamma irradiated. Values of ΔE were as much as 31.6 which is an acceptable match in commercial reproduction on printing presses.

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