scholarly journals Influence of storage temperature on vickers microhardness of resin composite

2018 ◽  
Vol 10 (1) ◽  
Author(s):  
Mayyadah Almozainy
Keyword(s):  
Vickers Microhardness ◽  
Storage Temperature ◽  
Resin Composite

scholarly journals Influence of storage temperature on vickers microhardness of resin composite

2018 ◽  
Vol 3 (2) ◽  
pp. 70
Author(s):  
Mayyadah Alomozainy
Keyword(s):  
Vickers Microhardness ◽  
Storage Temperature ◽  
Resin Composite

scholarly journals Influence of additional polymerization in the microhardness of direct composite resins

2010 ◽  
Vol 10 (2) ◽  
Author(s):  
Geraldo Henrique L. Lombardo ◽  
Cristiane F. Carvalho ◽  
Graziela Galhano ◽  
Rodrigo Othávio A. Souza ◽  
Lafayete N. Júnior ◽  
...  
Keyword(s):  
Vickers Microhardness ◽  
Resin Composite ◽  
Saint Paul ◽  
Metallic Matrix ◽  
Composite Resins ◽  
The Other ◽  
Distilled Water ◽  
Anova Test ◽  
Tukey Test

Objective: To evaluate different methods of additional polymerization in the Vickers’ microhardness of three composite resins. Material and Methods: With assistance of a metallic matrix (3 x 4mm), 30 specimens (sps) of each direct resin composite (drc) were prepared, entitled: Filtek Z250(3M ESPE, Saint Paul/MN-USA)(Gr1), W3D(Wilcos, Petrópolis/ RJ-Brazil)(Gr2), and EstheticX (Dentsply/York/PA-USA)(Gr3). All sps were photopolimerized, by the incremental technique, during 40 seconds (Gr1 - n=10: control). After that, 20 samples of each group were divided and half of the samples (n=10) were submitted to the additional polymerization during 15 minutes to 127ºC in autoclave (Gr2) and the other half in stove (Gr3). After all sps were stored in distilled water (37ºC/24 hours). The microhardness was accomplished in digital machine (Future-Tech, FM 700 Model), with 50kg of load. The data obtained (Kg/mm2) were analyzed utilizing the ANOVA Test (2 factors) and Tukey test (p<0.05). Results: The values of mean ± standar  deviations obtained were: Gr1a(84,2±5,1), Gr1b (71,6±6,7), Gr1c (89,6±7,4), Gr2a (101,1±6,0), Gr2b (96,4±9,0), Gr2c (112,6±7,3), Gr3a (74,0±6,5), Gr3b (66,0±12,7) e Gr3c (81,7±6,5). The polymerization in stove produced a higher microhardness than the other kinds of polymerization (p<0.05) and the microhardness of the resins statistically differed among them (p<0.05). Conclusion: The additional polymerization of the Filtek Z250 in the stove produced microhardness statistically higher than the others.

scholarly journals Evaluation of Two Resin Composites Having Different Matrix Compositions

2020 ◽  
Vol 8 (3) ◽  
pp. 76
Author(s):  
Tarek M. Elshazly ◽  
Christoph Bourauel ◽  
Dalia I. Sherief ◽  
Dalia I. El-Korashy
Keyword(s):  
Vickers Microhardness ◽  
Resin Composite ◽  
Blue Dye ◽  
Resin Composites ◽  
Methylene Blue Dye ◽  
Curing Time ◽  
Micro Computed Tomography ◽  
Time Data ◽  
Polymerization Shrinkage ◽  
Dye Penetration

This study compared two resin composites with similar filler systems and different matrix compositions. The depth of cure (DoC), polymerization shrinkage, and marginal leakage were evaluated. A Filtek Bulk Fill resin composite (FB) and a Filtek Supreme resin composite (FS) were used. For the DoC and polymerization shrinkage, cylindrical specimens with different thicknesses were prepared. The DoC was attributed to the bottom/top ratios of Vickers microhardness numbers. For polymerization shrinkage, each specimen was firstly scanned using micro-computed tomography (µCT) then cured for 20 s, then for 10 s, and then for 10 s, and they were rescanned between each curing time. Data were processed using the Mimics software. For marginal leakage, standardized 5 mm cavities were prepared in 90 molars. After etching and bonding, materials were packed according to groups: FB-bulk, FB-incremental, and FS-incremental, which were cured for 20, 30, and 40 s, respectively. After thermo-cycling, teeth were stored in 1% methylene blue dye for 24 h and then sectioned and observed for dye penetration. The results showed insignificant differences in the shrinkage and leakage between the different packing techniques and curing times of both materials. In conclusion, the introduction of a novel matrix into resin composite composition enabled bulk-filling in one layer up to 5 mm deep while keeping a tolerable polymerization shrinkage.

scholarly journals Impact of storage media and temperature on color stability of tooth-colored CAD/CAM materials for final restorations

2019 ◽  
Vol 17 (4) ◽  
pp. 228080001983683 ◽  
Author(s):  
Anja Liebermann ◽  
Dirk Vehling ◽  
Marlis Eichberger ◽  
Bogna Stawarczyk
Keyword(s):  
Red Wine ◽  
Storage Temperature ◽  
Resin Composite ◽  
Distilled Water ◽  
Storage Duration ◽  
Cad Cam ◽  
The Impact ◽  
And Storage ◽  
Storage Solution

Background: This in-vitro study examined the impact of storage solution, storage duration, and storage temperature on discoloration of three tooth-colored CAD/CAM materials for final restorations. Methods: Specimens ( N = 288; n = 96 per material) with a thickness of 1 ± 0.03 mm of the following CAD/CAM materials were fabricated: resin composite (Lava Ultimate, 3M), polymer-infiltrated ceramic (VITA Enamic, VITA Zahnfabrik), and leucite ceramic (IPS Empress CAD, Ivoclar Vivadent). After baseline measurement, specimens were stored in red wine, curry solution, cress solution, and distilled water at 37°C or 55°C. The discoloration was measured using a spectrophotometer (Lambda 35 Perkin Elmer, Perkin Elmer Inc.) after 1 and 7 days storage. Data were analyzed using four-way ANOVA followed by the Scheffé post-hoc test and partial eta squared ( ηP²) test ( p < 0.05). Results: The highest influence on ∆ E was exerted by storage duration ( ηP² = 0.295, p < 0.001), followed by storage solution ( ηP² = 0.171, p < 0.001), CAD/CAM material ( ηP² = 0.049, p < 0.001), and storage temperature ( ηP² = 0.033, p < 0.001). Specimens stored for 7 days in staining solutions showed more discoloration than those stored for just 1 day. Higher ∆ E values were achieved for specimens stored in curry solution, followed by red wine, cress solution, and distilled water. Resin composite Lava Ultimate showed larger ∆ E values compared with the resin hybrid ceramic VITA Enamic and leucite ceramic IPS Empress CAD. Specimens stored at 37°C showed significantly less discoloration than those stored at 55°C. Conclusions: The degree of coloration of the materials depends on food and temperature and was most pronounced with Lava Ultimate.

scholarly journals Effects of Delayed Finishing/Polishing on Surface Roughness, Hardness and Gloss of Tooth-Coloured Restorative Materials

2010 ◽  
Vol 04 (01) ◽  
pp. 050-056 ◽  
Author(s):  
A Ruya Yazici ◽  
Duygu Tuncer ◽  
Sibel Antonson ◽  
Alev Onen ◽  
Evren Kilinc
Keyword(s):  
Surface Roughness ◽  
Small Area ◽  
Vickers Microhardness ◽  
Resin Composite ◽  
Time Data ◽  
Hybrid Resin ◽  
Tukey Test ◽  
Restorative Materials ◽  
Hardness Values ◽  
One Way Anova

ABSTRACTObjectives: The aim of this study was to investigate the effect of delayed finishing/polishing on the surface roughness, hardness and gloss of tooth-coloured restorative materials.Methods: Four different tooth-coloured restoratives: a flowable resin composite- Tetric Flow, a hybrid resin composite- Venus, a nanohybrid resin composite- Grandio, and a polyacid modified resin composite- Dyract Extra were used. 30 specimens were made for each material and randomly assigned into three groups. The first group was finished/polished immediately and the second group was finished/polished after 24 hours. The remaining 10 specimens served as control. The surface roughness of each sample was recorded using a laser profilometer. Gloss measurements were performed using a small-area glossmeter. Vickers microhardness measurements were performed from three locations on each specimen surface under 100g load and 10s dwell time. Data for surface roughness and hardness were analyzed by Kruskal Wallis test and data for gloss were subjected to one-way ANOVA and Tukey test (P<.05).Results: The smoothest surfaces were obtained under Mylar strip for all materials. While there were no significant differences in surface roughness of immediate and delayed finished/polished Dyract Extra samples, immediately finished/polished Venus and Grandio samples showed significantly higher roughness than the delayed polished samples (P<.05). In Tetric Flow samples, immediately finishing/polishing provided smoother surface than delayed finishing/polishing (P<.05). The highest gloss values were recorded under Mylar strip for all materials. While delayed finishing/polishing resulted in a significantly higher gloss compared to immediate finishing/polishing in Venus samples (P<.05), no differences were observed between delayed or immediate finishing/polishing for the other materials (P>.05). The lowest hardness values were found under Mylar strip. Delayed finishing/polishing significantly increased the hardness of all materials.Conclusions: The effect of delayed finishing/polishing on surface roughness, gloss and hardness appears to be material dependent. (Eur J Dent 2010;4:50-56)

scholarly journals POST-CURE’S EFFECT ON THE DEPTH OF CURE OF A SHORT FIBER-REINFORCED RESIN COMPOSITE

2018 ◽  
Vol 9 ◽  
pp. 158
Author(s):  
Ellyza Herda ◽  
Nadia Safira Ninda ◽  
Mia Damiyanti
Keyword(s):  
Vickers Microhardness ◽  
Light Emitting Diode ◽  
Resin Composite ◽  
Short Fiber ◽  
T Test ◽  
Fiber Reinforced ◽  
Light Emitting ◽  
Depth Of Cure ◽  
Microhardness Profile ◽  
Light Curing

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.

scholarly journals PROPERTIES OF COMPOSITE RESIN ALKASIT AND ZIRCONIA-REINFORCED GLASS-IONOMER CEMENT IN DIFFERENT STORAGE

2020 ◽  
Vol 7 (1) ◽  
pp. 40
Author(s):  
Clarinda Vinindya ◽  
Cynthia Pratiwi ◽  
Yosi Kusuma Eriwati ◽  
Siti Triaminingsih ◽  
Decky J Indrani
Keyword(s):  
Vickers Microhardness ◽  
Composite Resin ◽  
Resin Composite ◽  
Testing Machine ◽  
Glass Ionomer Cement ◽  
Storage Conditions ◽  
Glass Ionomer ◽  
Surface Microhardness ◽  
Ionomer Cement ◽  
Microhardness Tester

Background: The temperature and salivary pH in a person's mouth are highly dynamic (e.g., before, during, and after eating) and so restorations in a cavity must be resilient to these variable conditions. Temperature and immersion conditions affect the mechanical properties of a restoration. This study aimed to determine the effect of environmental conditions on diametral tensile strength (DTS) and surface microhardness of a resin composite with alkaline fillers or zirconia–reinforced glass ionomer cement (Zr-reinforced GIC). Method: Thirty specimens of a resin composite with alkaline fillers (Cention-N, Ivoclar-Vivadent, Lichtenstein) and 30 specimens with zirconia-reinforced GIC (Zirconomer, Shofu, Japan) were stored at different conditions (23°C and 37°C; with and without immersion in water) for 24 hours. DTS was tested with a Universal Testing Machine (AGS-X series, Shimadzu, Japan) and surface microhardness was tested with a Vickers Microhardness tester (HMV-G Series Micro Vickers Microhardness Tester, Shimadzu, Japan). Data were analyzed statistically using a one-way ANOVA test (and Shapiro-Wilk test. Result: The values of microhardness and DTS increased significantly both for the composite resin alkasite and zirconia-reinforced GIC with increasing temperature in the groups without immersion. However, there was a significant decrease in microhardness and DTS after immersion in distilled water at 37°C for both the composite resin alkasite and zirconia-reinforced GIC. Conclusion: It can be concluded that storage conditions affect the microhardness and DTS of resin composite Alkasite and Zirconia-reinforced GIC

Silicification of wood-cell walls

1994 ◽  
Vol 52 ◽  
pp. 428-429
Author(s):  
S. E. Keckler ◽  
D. M. Dabbs ◽  
N. Yao ◽  
I. A. Aksay
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Cell Walls ◽  
Lignin Content ◽  
Resin Composite ◽  
Middle Lamella ◽  
Cellulose Fibers ◽  
Complex Structures ◽  
Rich Region ◽  
Inorganic Precursors

Cellular organic structures such as wood can be used as scaffolds for the synthesis of complex structures of organic/ceramic nanocomposites. The wood cell is a fiber-reinforced resin composite of cellulose fibers in a lignin matrix. A single cell wall, containing several layers of different fiber orientations and lignin content, is separated from its neighboring wall by the middle lamella, a lignin-rich region. In order to achieve total mineralization, deposition on and in the cell wall must be achieved. Geological fossilization of wood occurs as permineralization (filling the void spaces with mineral) and petrifaction (mineralizing the cell wall as the organic component decays) through infiltration of wood with inorganics after growth. Conversely, living plants can incorporate inorganics into their cells and in some cases into the cell walls during growth. In a recent study, we mimicked geological fossilization by infiltrating inorganic precursors into wood cells in order to enhance the properties of wood. In the current work, we use electron microscopy to examine the structure of silica formed in the cell walls after infiltration of tetraethoxysilane (TEOS).

Storage of Human Blood Platelets

1974 ◽  
Vol 32 (02/03) ◽  
pp. 405-416 ◽  
Author(s):  
M. R Hardeman ◽  
Carina J L. Heynens
Keyword(s):  
Storage Temperature ◽  
Platelet Rich Plasma ◽  
Blood Platelets ◽  
Storage Period ◽  
Serotonin Uptake ◽  
Hypotonic Shock ◽  
Glycolytic Intermediates

SummaryStorage experiments were performed at 4°, 25° and 37° C with platelet-rich plasma under sterile conditions. In some experiments also the effect of storing platelets at 4° C in whole blood was investigated.Before, during and after three days of storage, the platelets were tested at 37° C for their serotonin uptake and response to hypotonic shock. In addition some glycolytic intermediates were determined.A fair correlation was noticed between the serotonin uptake and hypotonic shock experiments. Both parameters were best maintained at 25° C. Also platelet counting, performed after the storage period, indicated 25° C as the best storage temperature. Determination of glycolytic intermediates did not justify any conclusion regarding the optimal storage temperature. Of the various anticoagulants studied, ACD and heparin gave the best results as to the serotonin uptake and hypotonic shock response, either with fresh or stored platelets. The use of EDTA resulted in the lowest activity, especially after storage.The results of these storage experiments in vitro, correspond well with those in vivo reported in the literature.

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