scholarly journals Physical-Mechanical Properties of Bulk Fill Composites Submitted to Biodegradation by Streptococcus mutans

2020 ◽  
Vol 31 (4) ◽  
pp. 431-439 ◽  
Author(s):  
Jessica Rodrigues Camassari ◽  
Lourenço Correr-Sobrinho ◽  
Américo Bortolazzo Correr ◽  
Julia Puppin-Rontani ◽  
Rafael Nobrega Stipp ◽  
...  
Keyword(s):  
Streptococcus Mutans ◽  
Surface Hardness ◽  
High Viscosity ◽  
Tukey Test ◽  
Before And After ◽  
Two Factors ◽  
Scanning Electron Microscope Data ◽  
Electron Microscope Data ◽  
Representative Samples ◽  
Scanning Electron

Abstract The aim of this study was to evaluate the Streptococcus mutans biofilm influence on the roughness (Ra), gloss (GU), surface hardness (KHN) and flexural strength (FS) of high viscosity bulk fill composites. Filtek Bulk Fill (FBF), Tetric N Ceram Bulk Fill (TNC), X-tra fil Bulk Fill (XF) and Filtek Z350 (FZ) were used. Ten discs of each composite were prepared for Ra, KHN and GU and 20 bars for the FS. After 24 h, specimens were polished and initial analyzes performed. Samples were sterilized and subjected to biodegradation for 7 days and final analyzes performed. Representative samples of each group were evaluated in Scanning Electron Microscope. Data were submitted to ANOVA two factors and Tukey test. XF presented the highest values (p<0.05) of Ra before and after biodegradation (0.1251; 0.3100), and FZ (0.1443) the lowest after biodegradation (p<0.05). The highest GU values (p<0.05) were observed for FZ (71.7; 62) and FBF (69.0; 64.6), and the lowest (p<0.05) for TNC (61.4; 53.3) and XF (58.5; 53.5), both before and after biodegradation. For KHN the highest values were obtained by XF (151.7; 106), and the (p< 0.05) lowest values for TNC (62.2; 51.8), both before and after biodegradation. The highest values (p<0.05) of FS were observed for FZ (127.6) and the lowest (p<0.05) for TNC (86.9); after biodegradation, XF (117.7) presented the highest (p<0.05) values compared to TNC and FZ.” In conclusion, biodegradation increased Ra and decreased GU and KHN for all. Concerning FS, degradation provided a significant decreased value only for FZ.

scholarly journals The effects of food simulating liquids on surface roughness, hardness, and solubility of bulk fill composites

2019 ◽  
Author(s):  
Özge Gizem Cabadağ ◽  
NİHAN GÖNÜLOL
Keyword(s):  
Surface Roughness ◽  
Citric Acid ◽  
Vickers Microhardness ◽  
Surface Hardness ◽  
High Viscosity ◽  
Constant Mass ◽  
Measuring Device ◽  
Hardness Values ◽  
Roughness Measurements ◽  
Scanning Electron

Abstract BackgroundThe aim of this study was to compare the effects of food simulating liquids (FSLs) on the surface roughness, surface hardness and solubility of bulk fill composites. MethodsTwo-hundred samples were prepared from four high viscosity bulk fill composites (SonicFillTM, Tetric® EvoCeram Bulk Fill, Beautifil-Bulk Restorative, FiltekTM Bulk Fill Posterior Restorative) and a microhybrid composite (FiltekTM Z250). After the initial weights of the samples were recorded (m1), surface roughness measurements were evaluated with a profilometer. The samples were stored in 4 different FSLs for 7 days, then the second surface roughness values were recorded. Then the samples were stored in a desiccator to reach the constant mass and the values were recorded as m2. The solubility levels were calculated according to the ISO 4049: 2009 specification. The surface hardness values of the samples were determined by using the Vickers microhardness measuring device. Twenty specimens from each group were evaluated in terms of surface morphology with scanning electron microscope (SEM).ResultsBeautifil Bulk Restorative was the most affected group in terms of surface roughness after storage in FSLs and citric acid caused the highest values in this group (p<0,005). Beautifil Bulk Restorative and Filtek Z250 groups showed the highest surface hardness values, while the Tetric EvoCeram group had the lowest. The highest solubility values were detected in Beautifil Bulk Restorative group, and citric acid and ethanol caused the highest solubility values on all the tested composites. ConclusionsBeautifil Bulk Restorative group showed significant differences from the other groups in all tested parameters.

scholarly journals Effect of thermocycling in a hard denture liner and acrylic resin after different chemical and mechanical polishing

2015 ◽  
Vol 63 (4) ◽  
pp. 397-404
Author(s):  
Graziella Morfim Schramm ALIGNANI ◽  
Juliana Maria Costa Nuñez PANTOJA ◽  
Jessica Mie Ferreira Koyama TAKAHASHI ◽  
Andréa Araújo de VASCONCELLOS ◽  
Marcelo Ferraz MESQUITA ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Impact Resistance ◽  
Surface Hardness ◽  
Physical And Mechanical Properties ◽  
Acrylic Resin ◽  
Mechanical Polishing ◽  
Tukey Test ◽  
Before And After ◽  
The Impact ◽  
Resistance Tests

Objective: To evaluate the effect of aging in a hard denture reline (New Truliner) and an acrylic resin (Classic) after chemical and mechanical polishing. Methods: Eighty specimens were made, divided randomly between 8 groups: G1.Acrylic Resin Classic (RAC)/Mechanical Polishing (PM); G2.RAC/PM + thermocycling (TR); G3) RAC/Chemical Polishing (PQ); G4.RAC/PQ + TR; G5.New Truliner (NT)/PM; G6.NT/PM + TR; G7. NT/PQ; G8.NT/PQ + TR. The surface hardness was measured before and after polishing, and after TR. The impact resistance tests were measured after all applied treatments. The data were submitted to ANOVA and Tukey test (a=5%). Results: Regardless of the polishing, it was noted that RAC presented significantly higher surface hardness than NT; PM had higher hardness in both materials compared with PQ; on both polishing, the impact resistance of the RAC was higher than NT. Independently of TR test, the impact resistance of the materials that received PQ was higher than received PM. The PQ caused greater changes in properties than the PM. Conclusion: Aging and chemical and mechanical polishing influenced the physical and mechanical properties of hard denture reline and acrylic resin.

scholarly journals Evaluation of the surface hardness of composite resins before and after polishing at different times

2006 ◽  
Vol 14 (3) ◽  
pp. 188-192 ◽  
Author(s):  
Michelle Alexandra Chinelatti ◽  
Daniela Thomazatti Chimello ◽  
Renata Pereira Ramos ◽  
Regina Guenka Palma-Dibb
Keyword(s):  
Statistical Analysis ◽  
Vickers Hardness ◽  
Composite Resin ◽  
Surface Hardness ◽  
Composite Resins ◽  
The Other ◽  
Test Results ◽  
Tukey Test ◽  
Natural Flow ◽  
Before And After

PURPOSE: The aim of this study was to evaluate the surface hardness of six composite resins: Revolution, Natural Flow, Fill Magic Flow, Flow-it! (flowables), Silux Plus (microfilled) and Z100 (minifilled) before and after polishing at different times. MATERIALS AND METHODS: For this purpose, 240 specimens (5mm diameter, 1.4mm high) were prepared. Vickers hardness was determined before and after polishing at different times: immediately, 24h, 7 and 21 days after preparation of the samples. Statistical analysis was performed by ANOVA and Tukey test. RESULTS: There was no difference in the hardness of flowable resins, which had lower hardness than the minifilled resin. The minifilled resin showed the highest surface hardness as compared to the other materials (p<0.01). All materials exhibited higher hardness after polishing, being more evident after 7 days. CONCLUSION: It may be concluded that, regardless of the composite resin, surface hardness was considerably increased when polishing was delayed and performed 1 week after preparation of the samples.

scholarly journals The effects of food simulating liquids on surface roughness, hardness, and solubility of bulk fill composites

2019 ◽  
Author(s):  
Özge Gizem Cabadağ ◽  
NİHAN GÖNÜLOL
Keyword(s):  
Surface Roughness ◽  
Citric Acid ◽  
Vickers Microhardness ◽  
Surface Hardness ◽  
High Viscosity ◽  
Constant Mass ◽  
Measuring Device ◽  
Hardness Values ◽  
Roughness Measurements ◽  
Scanning Electron

Abstract Abstract Background: The aim of this study was to compare the effects of food simulating liquids (FSLs) on the surface roughness, surface hardness and solubility of bulk fill composites. Methods: Two-hundred samples were prepared from four high viscosity bulk fill composites (SonicFill TM , Tetric® EvoCeram Bulk Fill, Beautifil-Bulk Restorative, Filtek TM Bulk Fill Posterior Restorative) and a microhybrid composite (Filtek TM Z250). After the initial weights of the samples were recorded (m 1 ), surface roughness measurements were evaluated with a profilometer. The samples were stored in 4 different FSLs for 7 days, then the second surface roughness values were recorded. Then the samples were stored in a desiccator to reach the constant mass and the values were recorded as m 2 . The solubility levels were calculated according to the ISO 4049: 2009 specification. The surface hardness values of the samples were determined by using the Vickers microhardness measuring device. Twenty specimens from each group were evaluated in terms of surface morphology with scanning electron microscope (SEM). Results: Beautifil Bulk Restorative was the most affected group in terms of surface roughness after storage in FSLs and citric acid caused the highest values in this group (p<0,005). Beautifil Bulk Restorative and Filtek Z250 groups showed the highest surface hardness values, while the Tetric EvoCeram group had the lowest. The highest solubility values were detected in Beautifil Bulk Restorative group, and citric acid and ethanol caused the highest solubility values on all the tested composites. Conclusions: Beautifil Bulk Restorative group showed the highest surface roughness and solubility values among the tested groups, while the same group showed the highest surface hardness. Key Words: Bulk fill composites, food simulating liquids, solubility, surface hardness, surface roughness.

scholarly journals Redox Mechanism of Azathioprine and Its Interaction with DNA

2021 ◽  
Vol 22 (13) ◽  
pp. 6805
Author(s):  
Mihaela-Cristina Bunea ◽  
Victor-Constantin Diculescu ◽  
Monica Enculescu ◽  
Horia Iovu ◽  
Teodor Adrian Enache
Keyword(s):  
Electron Microscopy ◽  
Mass Spectrometry ◽  
Scanning Electron Microscopy ◽  
Structural Changes ◽  
Differential Pulse ◽  
Immunosuppressive Drug ◽  
Redox Mechanism ◽  
Before And After ◽  
Dna Film ◽  
Scanning Electron

The electrochemical behavior and the interaction of the immunosuppressive drug azathioprine (AZA) with deoxyribonucleic acid (DNA) were investigated using voltammetric techniques, mass spectrometry (MS), and scanning electron microscopy (SEM). The redox mechanism of AZA on glassy carbon (GC) was investigated using cyclic and differential pulse (DP) voltammetry. It was proven that the electroactive center of AZA is the nitro group and its reduction mechanism is a diffusion-controlled process, which occurs in consecutive steps with formation of electroactive products and involves the transfer of electrons and protons. A redox mechanism was proposed and the interaction of AZA with DNA was also investigated. Morphological characterization of the DNA film on the electrode surface before and after interaction with AZA was performed using scanning electron microscopy. An electrochemical DNA biosensor was employed to study the interactions between AZA and DNA with different concentrations, incubation times, and applied potential values. It was shown that the reduction of AZA molecules bound to the DNA layer induces structural changes of the DNA double strands and oxidative damage, which were recognized through the occurrence of the 8-oxo-deoxyguanosine oxidation peak. Mass spectrometry investigation of the DNA film before and after interaction with AZA also demonstrated the formation of AZA adducts with purine bases.

scholarly journals Efficacy of Three Commercial Disinfectants in Reducing Microbial Surfaces’ Contaminations of Pharmaceuticals Hospital Facilities

2021 ◽  
Vol 18 (2) ◽  
pp. 779
Author(s):  
Giuseppina Di Martino ◽  
Salvatore Pasqua ◽  
Bruno Douradinha ◽  
Francesco Monaco ◽  
Chiara Di Bartolo ◽  
...  
Keyword(s):  
United States Pharmacopeia ◽  
Log10 Reduction ◽  
Colony Forming Units ◽  
Before And After ◽  
Disinfection Procedure ◽  
Cleaning And Disinfection ◽  
States Pharmacopeia ◽  
Representative Samples ◽  
Correct Implementation ◽  
Reduction Index

To evaluate and validate the efficacy of disinfectants used in our cleaning procedure, in order to reduce pharmaceutical hospital surfaces’ contaminations, we tested the action of three commercial disinfectants on small representative samples of the surfaces present in our hospital cleanrooms. These samples (or coupons) were contaminated with selected microorganisms for the validation of the disinfectants. The coupons were sampled before and after disinfection and the microbial load was assessed to calculate the Log10 reduction index. Subsequently, we developed and validated a disinfection procedure on real surfaces inside the cleanrooms intentionally contaminated with microorganisms, using approximately 107–108 total colony forming units per coupon. Our results showed a bactericidal, fungicidal, and sporicidal efficacy coherent to the acceptance criteria suggested by United States Pharmacopeia 35 <1072>. The correct implementation of our cleaning and disinfection procedure, respecting stipulated concentrations and contact times, led to a reduction of at least 6 Log10 for all microorganisms used. The proposed disinfection procedure reduced the pharmaceutical hospital surfaces’ contaminations, limited the propagation of microorganisms in points adjacent to the disinfected area, and ensured high disinfection and safety levels for operators, patients, and treated surfaces.

scholarly journals Cementitious Composites Reinforced with Polypropylene, Nylon and Polyacrylonitile Fibres

2012 ◽  
Vol 730-732 ◽  
pp. 271-276
Author(s):  
H.R. Pakravan ◽  
M. Jamshidi ◽  
M. Latifi ◽  
F. Pacheco-Torgal
Keyword(s):  
Absorption Capacity ◽  
Cement Matrix ◽  
Cementitious Composites ◽  
Scanning Electron Micrographs ◽  
Energy Absorption Capacity ◽  
Cement Ratio ◽  
Pull Out ◽  
Water To Cement Ratio ◽  
Before And After ◽  
Scanning Electron

This paper compares the adhesion strength between three polymeric fibres (polypropylene (PP), nylon66 (N66) and polyacrylonitrile (PAN)) embedded in a cement paste. The specimens were prepared at a water to cement ratio (w/c) of 0.5 and tested after 7, 14 and 28 curing days. It was found that although the adhesion between the polymeric fibres to the cement matrix is an important factor, the energy absorption capacity or energy dissipation ability of the fibres, plays a more important role in the improvement of the cementitious composites fracture toughness. Scanning electron micrographs were used to characterize the fibres surface before and after the Pull-out tests.

Impact of Resin Composite Viscosity and Fill-technique on Internal Gap in Class I Restorations: An OCT Evaluation

2021 ◽  
Author(s):  
KR Kantovitz ◽  
LL Cabral ◽  
NR Carlos ◽  
AZ de Freitas ◽  
DC Peruzzo ◽  
...  
Keyword(s):  
Repeated Measures ◽  
Resin Composite ◽  
Oral Care ◽  
High Viscosity ◽  
Class I ◽  
Low Viscosity ◽  
Significant Difference ◽  
Before And After ◽  
Internal Adaptation ◽  
Internal Gap

SUMMARY The aim of this in vitro study was to quantitatively evaluate the internal gap of resin composites of high-and low-viscosity used in single- and incremental-fill techniques in Class I cavities exposed to thermal cycling (TC) using optical coherence tomography (OCT). Cavities of 4-mm depth and 3-mm diameter were prepared in 36 third molars randomly distributed into four groups, according to viscosity of restorative resin-based composite (high or low viscosity, all from 3M Oral Care) and technique application (bulk or incremental fill) used (n=9): RC, high-viscosity, incremental-fill, resin-based composite (Filtek Z350 XT Universal Restorative); BF, high-viscosity, bulk-fill, resin-based composite (Filtek One Bulk Fill); LRC, low-viscosity, incremental-fill, resin-based composite (Filtek Z350 XT Flowable Universal Restorative); and LBF, low-viscosity, bulk-fill, resin-based composite (Filtek Flowable Restorative). Single Bond Universal Adhesive system (3M Oral Care) was used in all the experimental groups. The incremental-fill technique was used for RC and LRC groups (2-mm increments), and a single-layer technique was used for BF and LBF groups, as recommended by the manufacturer. The internal adaptation of the resin at all dentin walls was evaluated before and after TC (5000 cycles between 5°C and 55°C) using OCT images. Five images of each restored tooth were obtained. Images were analyzed using ImageJ software that measured the entire length of the gaps at the dentin–restoration interface. The length of gaps (μm) was analyzed using two-way repeated measures ANOVA and the Tukey tests (α=0.05). There was a significant interaction between material types and TC (p=0.006), and a significant difference among all material types (p&lt;0.0001), before and after TC (p&lt;0.0001). Increased internal gaps at the dentin–restoration interface were noticed after TC for all groups. RC presented the lowest value of internal gap before and after TC, while LBF showed the highest values of internal gap after TC. In conclusion, TC negatively affected the integrity of internal gap, whereas high-viscosity, incremental-fill, resin-based composite presented better performance in terms of internal adaptation than low-viscosity, bulk-fill materials in Class I cavities.

scholarly journals Evaluation of the Starch Quantification Methods of Musa paradisiaca, Manihot esculenta, and Dioscorea trífida Using Factorial Experiments

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
J. J. Lafont-Mendoza ◽  
C. A. Severiche-Sierra ◽  
J. Jaimes-Morales
Keyword(s):  
Manihot Esculenta ◽  
Extraction Method ◽  
Area Under The Curve ◽  
Raw Material ◽  
Factorial Experiments ◽  
Average Percentage ◽  
Musa Paradisiaca ◽  
Tukey Test ◽  
Vis Spectroscopy ◽  
Two Factors

Background. Starch and its products are used in a variety of ways for both the food and nonfood industries. A factorial experiment is carried out with two factors to explain the behavior of the percentage of starch, where the factors correspond to the extraction method and to the raw material. Method. Three methods were used in triplicate: the first followed the official technique of the Association of Official Analytical Chemists (AOAC), to perform acid hydrolysis and quantification of starch by Titulation; the second method involved the colorful reaction with iodine using the UV equipment to measure the absorbance and calculate the percentage of starch; as a third method the FTIR was used, through which the concentration of the starch was calculated by the area under the curve obtained from the spectrum. Results. there is an effect of both the method and the raw material on the percentage of starch, while there was no effect of the interaction; the Tukey test indicates that the highest average percentage of extraction occurs with the extraction method by Titulation and with the starch of Manihot esculenta. Conclusion. It is used as raw material. The method of quantification of starch by UV-VIS spectroscopy was the best for the study samples because it presented less deviation in relation to the FTIR and Titulation methods.

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