scholarly journals Evaluation of Porosity and Water Sorption in Conventionally Cured Modified Polymethyl Methacrylate Resin - An In Vitro Study

2021 ◽  
Vol 10 (13) ◽  
pp. 930-934
Author(s):  
Merin Mathew ◽  
Kamalakanth Shenoy ◽  
Ravishankar K. S.
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Polymethyl Methacrylate ◽  
Polymer Composite ◽  
Glass Fibre ◽  
Water Sorption ◽  
Control Group ◽  
Fibre Reinforcement ◽  
Sorption Rate ◽  
Scanning Electron

BACKGROUND Dimensional change and porosity in the polymethylmethacrylate based prosthesis affects its clinical performance. Hence, the present study aimed to evaluate the porosity and water sorption present in the modified polymethyl methacrylate polymer composite. METHODS Control group without fibre reinforcement and test groups with fibre reinforcement were prepared for the study. Three different fibres such as boron free-E glass fibre, untreated and plasma-treated polypropylene fibres in varying weight percentage and aspect ratio were considered for reinforcement. The porosity of the fractured surface was observed through a scanning electron microscope (scanning electron microscope) and sorption measured based on international standards organization (ISO) 1567:1999. RESULTS Control group exhibited porous structures, whereas all fibre-reinforced groups did not exhibit porous structure at the fracture surface. There was a significant difference in the sorption rate between control and test group (p < 0.001). Among fibrereinforced test groups, boron free E glass fibre reinforced polymethylmethacrylate exhibited maximum sorption followed by polypropylene fibre reinforced polymer test groups (p < 0.001). However, all samples showed sorption rate within the ISO specification. CONCLUSIONS Fiber reinforcement is an effective method to reduce porosity and water sorption in polymethylmethacrylate based polymer composite regardless of the fibre type. KEY WORDS Polymer Composite, Porosity, Water Sorption, Fiber Reinforcement, Polymethylmethacrylate

scholarly journals REMINERALIZATION EFFECT OF POLYASPARTIC ACID IN THE POLYMER-INDUCED LIQUID PRECURSOR PROCESS ON THE INTRAFIBRILLAR DENTIN (SCANNING ELECTRON MICROSCOPE AND ENERGY DISPERSIVE X-RAY ANALYSIS)

2020 ◽  
pp. 45-48
Author(s):  
RIVANTI IRMADELA DEVINA ◽  
ADELINE CLARISSA ◽  
NILAKESUMA DJAUHARIE ◽  
KAMIZAR NAZAR ◽  
RATNA MEIDYAWATI
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Energy Dispersive ◽  
Control Group ◽  
Polyaspartic Acid ◽  
Liquid Precursor ◽  
X Ray ◽  
Demineralized Dentin ◽  
Scanning Electron

Objective: This study aims to analyze remineralization that occurred in demineralized dentin following polyaspartic acid (pAsp) in PILP immersion.Methods: Sixteen dentin block samples were immersed in demineralized solution. The samples were divided into controls (no pAsp immersion) orpAsp immersion for 3, 7, or 14 days (n’s=4). The samples were evaluated using a scanning electron microscope (SEM) to observe morphology andenergy-dispersive X-ray (EDX) to observe calcium and phosphate levels.Results: SEM revealed that pAsp immersion resulted in significantly higher dentin remineralization compared to the control group. However, therewere no significant differences among 3, 7, and 14 days of immersion. EDX revealed that remineralization occurred by the deposition of calcium andphosphate ions.Conclusion: Including pAsp in the PILP process produced rapid remineralization of demineralized dentin.

Synthesize and Characterization Zr-Al-Si Post through Eggshell Membrane Strengthening with PMMA Matrix

2016 ◽  
Vol 696 ◽  
pp. 85-88
Author(s):  
Niko Eka Putra ◽  
Yosa Fendra ◽  
Denny Nurdin ◽  
Bambang Sunendar Purwasasmita
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Polymethyl Methacrylate ◽  
Sol Gel ◽  
Eggshell Membrane ◽  
Gel Method ◽  
Sol Gel Method ◽  
Three Point Bending ◽  
Hardness Tester ◽  
Scanning Electron

Zr-Al-Si posts were successfully synthesized using biotemplate of eggshell membrane by sol-gel method and strengthening with matrix of polymethyl methacrylate (PMMA). The dental posts made were analyzed with the scanning electron microscope (SEM), three point bending and microvickers hardness tester. There are two methods used to synthesized Zr-Al-Si posts, with calcination and without calcination. The synthesized mechanism is discussed here.

Molecular Interdiffusion of Hauling Theory between Dissimilar Polymers Based on Novel USW

2011 ◽  
Vol 221 ◽  
pp. 289-294 ◽  
Author(s):  
Guo Hong Zhang ◽  
Jian Hui Qiu ◽  
Liang Shao ◽  
Xie Fu
Keyword(s):  
Tensile Strength ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Polymethyl Methacrylate ◽  
Polymer Chains ◽  
The Novel ◽  
Welding Strength ◽  
Reptation Theory ◽  
Scanning Electron

Based on the novel USW method, the welds of Polylactide (PLA) - Polyformaldehyde (POM) and PLA - polymethyl methacrylate (PMMA) have been carried out. The interdiffusion processes of polymer chains have also been investigated according to the reptation theory and the hauling theory. The welding strengths are carried out by the universal tester and the rupture interfaces are observed using the scanning electron microscope. The best welding strength is 52MPa (90% compared with PLA of the PLA-POM system), which can reach the tensile strength of IPS. The molecules of POM are much easier to inter-diffuse than those of PLA and PMMA.

scholarly journals Evaluation of two different root-end cavity preparation techniques: A scanning electron microscope study

2013 ◽  
Vol 07 (02) ◽  
pp. 186-190 ◽  
Author(s):  
Seda Aydemir ◽  
Hale Cimilli ◽  
Afife Binnaz Hazar Yoruç ◽  
Nevin Kartal
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Control Group ◽  
Laser Materials ◽  
Cavity Preparation ◽  
Scanning Electron Microscope Study ◽  
Yag Laser ◽  
Significant Difference ◽  
Laser Group ◽  
Scanning Electron

ABSTRACT Objective: In this study, we aimed to evaluate and compare the dentinal walls of root-end cavities for the presence of cracks after cavity preparation using US retrotips and Er: YAG laser. Materials and Methods: Fifty single-rooted teeth were prepared by Protaper NiTi rotary system and obturated by lateral condensation. Three milimeters of root-end was resected. Twenty teeth were prepared with US retrotip (Group 1), 20 teeth with Er: YAG laser (Group 2), and 10 teeth without retropreparation (control group). The root-end surfaces were examined under a scanning electron microscope (SEM). Then the cracks of the resected root surfaces were evaluated on microphotographs. Results: No statistically significant difference was detected between US Group and Laser Group for complete, incomplete, intradentinal, and total number of cracks (P = 0.47, P = 0.80, P = 0.69, P = 0.869, respectively). Conclusion: Statistical analysis revealed no significant effect of retropreparation technique on the development of apical cracks (P > 0.05).

scholarly journals Attempt to assess the infiltration of enamel made with experimental preparation using a scanning electron microscope

Open Medicine ◽  
2015 ◽  
Vol 10 (1) ◽  
Author(s):  
Małgorzata Skucha-Nowak
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Test Group ◽  
Control Group ◽  
Depth Of Penetration ◽  
Human Teeth ◽  
X Ray ◽  
Demineralized Enamel ◽  
Experimental Preparation ◽  
Scanning Electron

AbstractIntroduction: The resin infiltration technique, a minimally invasive method, involves the saturation, strengthening, and stabilization of demineralized enamel by a mixture of polymer resins without the need to use rotary tools or the risk of losing healthy tooth structures.Aim of the study:1. To design and synthesize an experimental infiltrant with potential bacteriostatic properties.2. To compare the depth of infiltration of the designed experimental preparation with the infiltrant available in the market using a scanning electron microscope.Material and Methods: Composition of the experimental infiltrant was established after analysis of 1H NMR spectra of the commercially available compounds that can penetrate pores of demineralized enamel. As the infiltrant should have bacteriostatic features by definition, an addition of 1% of monomer containing metronidazole was made. Thirty extracted human teeth were soaked in an acidic solution, which was to provide appropriate conditions for demineralization of enamel. Afterward, each tooth was divided along the coronal-root axis into two zones. One zone had experimental preparation applied to it (the test group), while the other had commercially available Icon (the control group). The teeth were dissected along the long axis and described above underwent initial observation with use of a Hitachi S-4200 scanning electron microscope.Results: It was found that all samples contained only oxygen and carbon, regardless of the concentration of additions introduced into them. The occurrence of carbon is partially because it is a component of the preparation in question and partially because of sputtering of the sample with it. Hydrogen is also a component of the preparation, as a result of its phase composition; however, it cannot be detected by the EDS method.Conclusions:1. SEM, in combination with X-ray microanalysis, does not allow one to explicitly assess the depth of penetration of infiltration preparations into enamel.2. In order to assess the depth of penetration of infiltration preparations with use of X-ray microanalysis, it is recommended to introduce a contrast agent that is approved for use in dental materials, such as ytterbium III fluoride.

Sperm abnormalities in matrinxã Brycon amazonicus after hormonal treatment with carp pituitary extract and Ovaprim™

Zygote ◽  
2018 ◽  
Vol 26 (4) ◽  
pp. 279-285
Author(s):  
Rosilane Gomes de Souza de Oliveira ◽  
Arley Faria José de Oliveira ◽  
Marle Angélica Villacorta Correa
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Hormonal Treatment ◽  
Control Group ◽  
Pituitary Extract ◽  
Nacl Solution ◽  
Sperm Analysis ◽  
Treatment Groups ◽  
Sperm Abnormalities ◽  
Scanning Electron

SummaryThe aim of this study was to evaluate if hormonal treatment causes changes in the morphology of matrinxã Brycon amazonicus spermatozoa. Twelve males were randomized into three treatment groups: 1, Ovaprim™ (0.5 ml/kg); 2, carp pituitary extract (CPE; 2.0 mg/kg); and 3, NaCl solution 0.9% – control group (0.5 ml/kg); with four replicates. Morphological sperm analysis was performed using an optical and scanning electron microscope. The percentage of normal spermatozoa (49.6±4.6% to 60.8±2.8%), with primary (26.1±6.4% to 45.3±4.5%) and secondary abnormalities (4.4±2.9% to 13.9±3.5%) did not differ significantly between treatment groups. There were no significant differences between treatments in relation to the primary abnormalities found in the head (10.5±3.8% to 25.5±6.3%), the midpiece (0.1±0.1% to 0.2±0.2%) and in the flagellum (18.9±3.8% to 15.5±3.1%), as well as in the secondary abnormalities, located in the head (0.8±0.4% to 7.8±4.6%) and in the flagellum (2.2±1.1% to 6.1±1.5%). When each abnormality was evaluated individually, only the percentage of degenerated head was higher in the CPE-induced group (24.9±5.9%) than the control group (7.2±3.1%). We concluded that the use of pituitary extract of carp or Ovaprim™ under the conditions of this experiment does not influence the percentage of sperm abnormalities in B. amazonicus.

Experimental study of polymethyl methacrylate: damage under corona discharge

2018 ◽  
Vol 82 (3) ◽  
pp. 31301
Author(s):  
Nora Kireche ◽  
Sébastien Rondot ◽  
Ferroudja Bitam-Megherbi ◽  
Omar Jbara ◽  
Mickael Gilliot ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Corona Discharge ◽  
Polymethyl Methacrylate ◽  
Electron Irradiation ◽  
Degradation Mechanism ◽  
Dielectric Behavior ◽  
Chemical Degradation ◽  
Surface Damages ◽  
Scanning Electron

In high-voltage applications, insulators may be exposed to corona discharges during long periods. In this experimental work, corona discharge tests of different durations are carried out in air at atmospheric pressure on polymethyl methacrylate (PMMA) samples. The resulting surface degradation is studied with several techniques. The surface damages are observed with environmental scanning electron microscope and atomic force microscopy. The results show that electrical trees occur on the surface of material and their distribution depends on the corona discharge duration. The chemical changes on PMMA surface are analyzed by Fourier transform infrared spectroscopy and a chemical degradation mechanism is proposed. Evolution of surface resistivity with corona aging is also implemented by using a classical I(V) method. In addition, to study the dielectric behavior of PMMA, the monitoring of kinetics of the trapped charge under electron irradiation in a scanning electron microscope is performed. The charging ability of PMMA under electron irradiation and its time constant of charging decrease with electrical aging.

Scanning electron microscope and energy dispersive X-ray spectrometry studies on the material surface of extruded Polycel® ossicular prostheses

2004 ◽  
Vol 118 (11) ◽  
pp. 840-844 ◽  
Author(s):  
Chul Ho Jang ◽  
Pa-Chun Wang
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Energy Dispersive ◽  
Fibrous Capsule ◽  
Rank Test ◽  
Material Surface ◽  
Control Group ◽  
X Ray ◽  
Ossicular Replacement ◽  
Scanning Electron

Background: The cause of ossicular prosthesis extrusion remains an issue of interest to many otologists. This study evaluated the change in material surfaces and chemical elements of extruded total ossicular replacement prostheses (TORPs) and partial ossicular replacement prostheses (PORPs).Methods: A total of nine extruded Polycel® ossicular prostheses (four TORPs, five PORPs) from nine patients was investigated using scanning electron microscope and energy dispersive X-ray spectrometry (EDX). Three prostheses (TORPs) obtained during revision surgery for hearing restoration were used as control subjects for EDX study.Results: All subjects from the study group showed loss of fibrous capsule at both platform and shaft in the extruded prostheses. In comparison with the control group, the extruded prostheses had a lower level of carbon element (Wilcoxon signed-rank test, p < 0.05).Conclusion: Loss of fibrous capsule and micro-degradation are probably two of the many factors that contribute to the extrusion of ossicular prostheses.

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