scholarly journals The Effect of Incorporation of Cellulose Kenaf Fibers in Composite Resin on Mechanical Properties and Surface Topography Analysis Using Scanning Electron Microscopy

Author(s):  
Nur Aliya Ibrahim ◽  
Rabihah Alawi ◽  
Yanti Johari ◽  
Nor Aidaniza Abdul Muttlib ◽  
Mohd Nazrulhuzaimi Md Yusoff

Abstract Objective This study aimed to evaluate the flexural and compressive strength of kenaf-reinforced composite resin as well as analyze the length and diameter of kenaf fibers and their surface topography. Materials and Methods Kenaf fibers were alkaline treated and wetted with coupling agent. Kenaf-reinforced composite resin was fabricated manually. Specimens for kenaf-reinforced composite resin (Tetric N Flow [Ivoclar Vivadent, Liechtenstein] + 2% kenaf) and control group (Tetric N Flow [Ivoclar Vivadent, Liechtenstein]) were prepared using stainless steel molds with dimension of 25 mm × 2 mm × 2 mm and 6 mm × 4 mm for flexural and compressive strength tests, respectively, and tested using Instron Universal Testing Machine (Shimadzu, Japan). Raw kenaf fibers, treated kenaf fibers, and fractured sample from flexural strength test were analyzed using scanning electron microscopy (SEM) (FEI Quanta FEG 450, United States). Data were analyzed using independent sample t-test. Significant level was set at p < 0.05. Results Kenaf-reinforced composite resin has a lower flexural and compressive strength than the control group (p < 0.05). SEM analysis revealed the average fibers’ length to be 1.24 mm and diameter ranging from 6.56 to 12.9 μm. The fibers dispersed in composite as single strand or a bundle with a minimal gap between fibers and composite. Conclusion Flexural and compressive strengths of kenaf-reinforced composite resin were lower than the control group, despite some adaptation between kenaf fibers and composite noted. The fibers’ length and diameter were reasonable for the dispersion in the resin matrix; however, additional treatments of kenaf are required for a favorable result.

2012 ◽  
Vol 18 (2) ◽  
pp. 289-294 ◽  
Author(s):  
Luís Eduardo Silva Soares ◽  
Louise Ribeiro Cortez ◽  
Raquel de Oliveira Zarur ◽  
Airton Abrahão Martin

AbstractOur aim was to test the hypothesis that the use of mouthwashes, consumption of soft drinks, as well as the type of light curing unit (LCU), would change the surface roughness (Ra) and morphology of a nanofilled composite resin (Z350® 3M ESPE). Samples (80) were divided into eight groups: Halogen LCU, group 1, saliva (control); group 2, Pepsi Twist®; group 3, Listerine®; group 4, Colgate Plax®; LED LCU, group 5, saliva; group 6, Pepsi Twist®; group 7, Listerine®; group 8, Colgate Plax®. Ra values were measured at baseline, and after 7 and 14 days. One specimen of each group was prepared for scanning electron microscopy analysis after 14 days. The data were subjected to multifactor analysis of variance at a 95% confidence followed by Tukey's honestly significant difference post-hoc test. All the treatments resulted in morphological changes in composite resin surface, and the most significant change was in Pepsi Twist® groups. The samples of G6 had the greatest increase in Ra. The immersion of nanofilled resin in mouthwashes with alcohol and soft drink increases the surface roughness. Polymerization by halogen LCU (reduced light intensity) associated with alcohol contained mouthwash resulted in significant roughness on the composite.


2017 ◽  
Vol 12 (1) ◽  
pp. 63-77 ◽  
Author(s):  
Siriporn Sirikingkaew ◽  
Nuta Supakata

This study presents the development of geopolymer bricks synthetized from industrial waste, including fly ash mixed with concrete residue containing aluminosilicate compound. The above two ingredients are mixed according to five ratios: 100:0, 95:5, 90:10, 85:15, and 80:20. The mixture's physico-mechanical properties, in terms of water absorption and the compressive strength of the geopolymer bricks, are investigated according to the TIS 168-2546 standard. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses are used to investigate the microstructure and the elemental and phase composition of the brick specimens. The results indicate that the combination of fly ash and concrete residue represents a suitable approach to brick production, as required by the TIS 168–2546 standard.


2020 ◽  
Vol 10 (18) ◽  
pp. 6513
Author(s):  
Emilia Bologa ◽  
Simona Stoleriu ◽  
Gianina Iovan ◽  
Cristina Angela Ghiorghe ◽  
Irina Nica ◽  
...  

This in vitro study evaluated the effects of dentifrices containing nano-hydroxyapatite (n-HAp) on dentinal tubule occlusion and on mineral deposition. Dentin specimens of ten human teeth were submersed for 30 s in 40% citric acid and then randomly divided into four groups (three study groups and one control group). In the study groups, the dentin samples were exposed to three different n-HAp toothpastes: Karex (Dr. Kurt Wolff GmbH & Co. KG, Bielefeld, Germany), Biorepair Plus Sensitive (Coswell SpA, Bologna, Italy), and Dr. Wolff’s Biorepair (Dr. Kurt Wolff GmbH & Co. KG, Bielefeld, Germany); in the control group no toothpaste was applied. All of the samples were evaluated using scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) analysis. In the control group all of the samples showed a frank and wide opening of the dentinal tubules, whereas in the study groups different degrees of tubule closure by mineral depositions were observed. Toothpastes containing n-HAp determined a significant occlusion of dentinal tubules and a significant increase of mineral deposition on the dentin surface. All three tested toothpastes showed similar results regarding the degree of dentinal tubule closure. Varying degrees of differences in calcium, phosphate, carbon, and oxygen ion concentrations among the three tested toothpastes were obtained.


2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Lucas Pereira Borges ◽  
Julio Cesar Campos Ferreira-Filho ◽  
Julia Medeiros Martins ◽  
Caroline Vieira Alves ◽  
Bianca Marques Santiago ◽  
...  

The purpose of this work was to verifyin vitroadherence ofE. corrodensandS. oralisto the surface of tongue piercings made of surgical steel, titanium, Bioplast, and Teflon. For this, 160 piercings were used for the count of Colony Forming Units (CFU) and 32 piercings for analysis under scanning electron microscopy. Of these, 96 (24 of each type) were individually incubated in 5 mL of BHI broth and 50 μL of inoculum at 37°C/24 h. The other 96 piercings formed the control group and were individually incubated in 5 mL of BHI broth at 37°C/24 h. Plates were incubated at 37°C/48 h for counting of CFU/mL and data were submitted to statistical analysis (pvalue<0.05). ForE. corrodens, difference among types of material was observed (p<0.001) and titanium and surgical steel showed lower bacterial adherence. The adherence ofS. oralisdiffered among piercings, showing lower colonization (p<0.007) in titanium and surgical steel piercings. The four types of piercings were susceptible to colonization byE. corrodensandS. oralis, and bacterial adhesion was more significant in those made of Bioplast and Teflon. The piercings presented bacterial colonies on their surface, being higher in plastic piercings probably due to their uneven and rough surface.


1997 ◽  
Vol 4 (1) ◽  
pp. 29-33 ◽  
Author(s):  
T. Hauge ◽  
J. Persson ◽  
Å. Nilsson

Twenty-four chronic alcoholics admitted to hospital for detoxification after a drinking spree were examined by upper gastrointestinal endoscopy. Biopsy specimens were taken from corpus/fundus, antrum and duodenum for tissue histology (eosin stain). From the duodenum villus index and ultrastructure (scanning electron microscopy, SEM) were also performed. As a control group 12 subjectively healthy non-alcoholics referred to upper gastrointestinal endoscopy mainly for dyspepsia were chosen.Gastrointestinal symptoms were common in alcoholics (88%). Endoscopic and histological gastroduodenitis were not more common in the alcohol group. There was no correlation between gastrointestinal symptoms and endoscopic or histological gastroduodenitis in both groups. In the duodenum, 50% of the alcoholics and 82% in the control group had alterations by scanning electron microscopy. Ten of the 11 alcoholics with an abnormal ultrastructure had diarrhoea. In the control group dyspepsia (ulcus suspect) was correlated to a pathological SEM.


2014 ◽  
Vol 541-542 ◽  
pp. 388-391
Author(s):  
Long Ma ◽  
Guo Zhong Li

Red mud lightweight baking-free brick was prepared by red mud, fly ash and cement, mixed with a certain amount of activator agent and foaming agent. The influence of foaming agent on properties of red mud lightweight baking-free brick was studied. The micro-structure of red mud lightweight baking-free brick was characterized by scanning electron microscopy (SEM). The results show that when the foaming agent content is 10ml, the sample with better performance obtained and the density is 423kg/m3, flexural strength is 0.49MPa and compressive strength is 1.87MPa.


1976 ◽  
Vol 55 (1) ◽  
pp. 107-110 ◽  
Author(s):  
Abraham Abramovich ◽  
Ricardo L. Macchi ◽  
Lucía M. Ribas

The surface of tooth enamel that had been left in contact with a phosphoric acid solution or a zinc phosphate cement mix was studied by scanning electron microscopy. Both treatments modified enamel surface topography. The modifications were represented by cavities of varying extension and depth.


1973 ◽  
Vol 59 (4) ◽  
pp. 667 ◽  
Author(s):  
John E. Ubelaker ◽  
V. F. Allison ◽  
Robert D. Specian

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