Segui questo link per vedere altri tipi di pubblicazioni sul tema: Micro-hybrid composite resins.
Articoli di riviste sul tema "Micro-hybrid composite resins"
Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili
Vedi i top-50 articoli di riviste per l'attività di ricerca sul tema "Micro-hybrid composite resins".
Accanto a ogni fonte nell'elenco di riferimenti c'è un pulsante "Aggiungi alla bibliografia". Premilo e genereremo automaticamente la citazione bibliografica dell'opera scelta nello stile citazionale di cui hai bisogno: APA, MLA, Harvard, Chicago, Vancouver ecc.
Puoi anche scaricare il testo completo della pubblicazione scientifica nel formato .pdf e leggere online l'abstract (il sommario) dell'opera se è presente nei metadati.
Vedi gli articoli di riviste di molte aree scientifiche e compila una bibliografia corretta.
1
Stoleriu, Simona, Sorin Andrian, Irina Nica, Andrei Victor Sandu, Galina Pancu, Alice Murariu e Gianina Iovan. "Evaluation of Adhesive Capacity of Universal Bonding Agents Used in Direct Composite Resins Repair". Materiale Plastice 54, n. 3 (30 settembre 2017): 574–77. http://dx.doi.org/10.37358/mp.17.3.4899.
Testo completoAbstract (sommario):
The aims of the study were to characterise the resin-resin interface when a universal bonding agent (UBA) was used in two different strategies in direct composite repair and to evaluate the bonding capacity of UBA by microleakage assessment. In study groups a micro-filled hybrid and a nano-filled hybrid composite resins were aged in order to simulate an old restorations. As a repair material was chosen the same micro-filled hybrid composite resin that was used as an old restoration. UBA was applied in etch-and-rinse and self-etch strategies and was used as an intermediate layer in repair procedure. After the repair the samples were aged again. In control groups were included non-aged, repaired composite resins samples. The resin-resin interface was characterised on SEM images and the microleakage at the interface was evaluated by dye penetration assessment. Universal bonding agent used in direct composite resins repair showed a very good adaptation to non-aged micro-filled hybrid and nano-filled hybrid composite resins. Aging by saliva storage of repaired composite resins leaded to an enlargement of resin-resin junction and a increased microleakage irrespective of the strategy (etch-and-rinse or self -etch) used for bonding agent application. Etch-and-rinse strategy for universal bonging agent application determined a better interface bonding when compared to self -etch strategy.
2
Andrian, Sorin, Galina Pancu, Claudiu Topoliceanu, Nicoleta Tofan, Simona Stoleriu e Gianina Iovan. "Evaluation of Compressive Strength of Repaired Direct Composite Resin Restorations". Revista de Chimie 68, n. 8 (15 settembre 2017): 1874–78. http://dx.doi.org/10.37358/rc.17.8.5783.
Testo completoAbstract (sommario):
The aim of the study was to evaluate and to compare the compressive parameters of repaired composite restoration when using different types of composite resins and a universal bonding agent as an intermediate layer. Aged micro-filled hybrid and nano-filled hybrid composite resins were chosen to simulate old restoration. The same micro-filled hybrid composite resin was used as a repair material. A universal bonding agent applied in etch-and-rinse and self etch strategies was used as an intermediate layer in restoration repair. Non-aged composite resins were considered as control. Compressive strength and compressive modulus were determined by evaluating the samples in a universal testing machine. Lower values of the tested parameters were recorded after aging both types of composite resin when compared to control. Higher values of compressive strength were recorded when nano-filled hybrid composite resin was repaired when compared to micro-filled hybrid composite resin. The strategy of universal bonding agent application as an intermediate layer did not influenced the compressive properties of repaired restoration.
3
Nogueira, Ruchele Dias, Rosa Maria Pereira Moisés Barbosa Andrade, Ailla Carla Rocha Acosta Lancellotti, Regina Guenka Palma-Dibb e Vinícius Rangel Geraldo-Martins. "Effect of Chemical Degradation on Surface Roughness and on Color Stability of Micro hybrid and Nanofilled Composites". Journal of Health Sciences 20, n. 3 (31 ottobre 2018): 167. http://dx.doi.org/10.17921/2447-8938.2018v20n3p167-172.
Testo completoAbstract (sommario):
ResumoA resina composta é o material restaurador mais utilizado atualmente. Apesar de seu sucesso clínico, o material está sujeito a alterações em suas propriedades físicas, quando exposto ao meio bucal. O objetivo foi avaliar a influência da degradação química na estabilidade de cor e na rugosidade superficial de resinas micro-híbrida e nanoparticulada. Foram confeccionados 40 discos (6,0mm x 2,0mm) da resina composta micro-híbrida (Z250XT) e 40 da resina nanoparticulada (Z350XT). Após a análise da cor inicial e da rugosidade inicial, 10 discos de cada resina foram imersos em saliva artificial (Controle, pH=6,4), suco de laranja (pH= 3,4), refrigerante de limão (pH=2,9) e vinho tinto (pH=3,1), por 4 horas por dia (37ºC) durante 30 dias. Após, foram realizadas as leituras finais de cor e rugosidade. Os dados obtidos para a estabilidade de cor foram analisados pelo Teste de Kruskal-Wallis, seguido pelo Teste de Dunn (α=5%). Para a análise da rugosidade foi utilizado o Teste t para amostras pareadas (α=5%). O manchamento provocado pela saliva artificial, suco de laranja e refrigerante foi similar, mas foi estatisticamente diferente do manchamento produzido pelo vinho, em ambas as resinas testadas. O vinho produziu o mesmo grau de manchamento nas resinas micro-híbrida e nanoparticulada. Foi observado que o suco de laranja, o refrigerante e o vinho promoveram aumento da rugosidade superficial dos discos de resina. Diante disso, concluiu-se que o vinho alterou a cor de resinas compostas micro-híbrida e nanoparticulada, e que a rugosidade superficial dos discos de resina foi alterada por todas as bebidas utilizadas.Palavras chave: Resinas Compostas. Corantes. Cor.Abstract Composite resin is the most used restorative material. Despite its clinical success, it is susceptible to changes in its physical properties when exposed to the oral environment. The aim was to evaluate the influence of acidic beverages on the color stability and on the surface roughness of the nanofilled and micro hybrid composite. Forty discs (6.0mm x 2.0mm) of the micro hybrid composite (Z250XT) and 40 of the nanofilled composite (Z350XT) were manufactured. After the measurement of the initial color and the initial roughness, 10 discs of each composite were individually immersed in artificial saliva (control, pH = 6.4), orange juice (pH=3.4), lime soda (pH = 2.9) and red wine (pH = 3.1) during 4 hours per day at 37°C for 30 days. At the end of the experiment, the final analysis of color and surface roughness were performed. The data obtained for the color stability were analyzed by Kruskal-Wallis and Dunn’s test (α= 5%). For the analysis of the surface roughness, the t test for related samples was used (α= 5%). The color changes promoted by artificial saliva, orange juice and soda were similar, but they were statistically different from staining produced by wine, in both tested composites. Wine produced the same degree of staining in both composites. Orange juice, soda and red wine increased the surface roughness of the composite discs. It was concluded that red wine significantly changes the color of micro hybrid and nanofilled composites. Furthermore, all beverages increased the surface roughness of the composites tested in the study herein.Keywords: Composite Resins. Coloring Agents. Color.
4
Cinelli, Francesca, Daniele Scaminaci Russo, Michele Nieri e Luca Giachetti. "Stain Susceptibility of Composite Resins: Pigment Penetration Analysis". Materials 15, n. 14 (13 luglio 2022): 4874. http://dx.doi.org/10.3390/ma15144874.
Testo completoAbstract (sommario):
Composite resins are considered the material of choice for esthetic direct restorations, considering both their satisfying esthetic and mechanical properties. The success of composite resin restorations depends highly on their color stability. Discoloration causes color mismatch, consequent patient dissatisfaction, and eventually additional costs for correction/replacement of the restoration. The purpose of this study was to evaluate the degree of pigment penetration within the composite resins, in order to understand how discoloration can be treated properly. Two different commercially available composite resins were compared in the study: a nano-filled composite resin and a non-homogeneous micro-hybrid composite resin. A coffee solution was used to induce staining of the materials. Subsequently, the penetration of the pigments was measured by analyzing the color from the outside to the inside of the specimen. 14 levels were analyzed starting from 0.1 mm to 3.0 mm in depth. The ANOVA test demonstrated a statistically significant difference (p < 0.0001) between test and control groups up to a depth of 1.0 mm for the nano-filled composite and up to a depth of 2.0 mm for the non-homogeneous micro-hybrid composite. The two composite resin materials, subjected to pigmenting treatment, underwent a color variation with different patterns.
5
Rajasekhar, Reshma, Baby James, Minimol K. Johny e Jose Jacob. "Evaluation of the effect of two commercially available non-alcoholic mouth rinses on the microhardness of composite material - An invitro study". Current Dental Research Journal 1, Issue 1 (30 maggio 2019): 14–21. http://dx.doi.org/10.12944/cdrj.01.o1.03.
Testo completoAbstract (sommario):
Composites have been widely used for anterior as well as posterior restorations due to increased aesthetic demands. Composite restorations placed in patients oral cavity is subjected to masticatory load, pH changes and chemical effect due to mouthwashes, beverages, food etc and the detrimental effects associated with these challenges on the microhardness of composite has to be determined. The study was conducted to evaluate the effect of two commercially available non-alcoholic mouth rinses on the microhardness of micro-hybrid and nanohybrid composite resins. Forty disc-shaped composite specimens were made from each type of composite materials and were divided into 5 groups with 8 samples each, Group 1= Microhybrid+Chlorhex, Group2=Microhybrid + Hexidine, Group3= Nanohybrid + Chlorhex, Group4= Nanohybrid+ Hexidine, Group 5= Nanohybrid and Micro hybrid + artificial saliva(Control).The samples were immersed in mouthrinses for 24 hrs and microhardness was subsequently measured using a Vicker’s microhardness tester. There was no significant difference in microhardness values of tested composite resins in either mouth rinses when compared to composites immersed in artificial saliva. Non-alcoholic mouth rinses do not affect the microhardness of micro-hybrid and nanohybrid composites.
6
Alnasser, Hamad A., Ahmed A. Elhejazi, Abdalrahman A. Al-Abdulaziz, Saad S. Alajlan e Syed Rashid Habib. "Effect of Conventional and Electronic Cigarettes Smoking on the Color Stability and Translucency of Tooth Colored Restorative Materials: An In Vitro Analysis". Coatings 11, n. 12 (20 dicembre 2021): 1568. http://dx.doi.org/10.3390/coatings11121568.
Testo completoAbstract (sommario):
This in vitro study compared the effects of conventional and electronic cigarettes on the aesthetics (color stability and translucency) of two types of composite resins: micro and nano-hybrid. Methods: A total of 120 specimens from two different composite materials Filtek Z250 XT (Nano-hybrid, 3M) and Filtek Z250 (Micro-hybrid, 3M) were divided into four groups (n = 30); shade A2 was used. The samples were exposed to conventional and electronic cigarette smoke via a custom made chamber device. The color values and measurements were recorded using a spectrophotometer before and after the exposure. The color and translucency were evaluated using the three-dimensional CIE Lab. Results: There was a significant change in the color (ΔE) and the translucency parameter (TP) in all of the specimens exposed to electronic cigarettes and conventional cigarettes. The results showed that the highest ΔE mean is for the nano-hybrid composite exposed to conventional cigarettes with 1.74 ΔE while the same material is 0.64 under the electronic cigarettes and the difference is significant with (p < 0.05). The micro-hybrid composite data showed less changes in color under both exposures with 0.85 ΔE mean under the conventional cigarette smoke and 0.48 under the electronic cigarette smoke with (p < 0.004). Conclusions: The conventional cigarette smoke has more effect on the color stability of the composite resins than electronic cigarettes. From a clinical point of view, the effect of smoke exposure on the tested specimens’ color, for the time duration to which the specimens were exposed, were moderate (ΔE < 2). The micro-hybrid composites showed better color stability as compared to the nano-hybrid composites.
7
Brunharo, Ione Helena Vieira Portella, Daniel Jogaib Fernandes, Mauro Sayão de Miranda e Flavia Artese. "Influence of surface treatment on shear bond strength of orthodontic brackets". Dental Press Journal of Orthodontics 18, n. 3 (giugno 2013): 54–62. http://dx.doi.org/10.1590/s2176-94512013000300010.
Testo completoAbstract (sommario):
INTRODUCTION: The shear bond strength of orthodontic brackets bonded to micro-hybrid and micro-particulate resins under different surface treatment methods was assessed. METHODS: Two hundred and eighty test samples were divided into 28 groups (n = 10), where 140 specimens were filled with Durafill micro-particulate resin and 140 with Charisma composite. In 140 samples, a coupling agent (silane) was applied. The surface treatment methods were: Phosphoric and hydrofluoric acid etching, sodium bicarbonate and aluminum oxide blasting, stone and burs. A Universal Instron Machine was used to apply an occlusal shear force directly to the resin composite bracket surface at a speed of 0.5 mm/min. The means were compared using analysis of variance and multivariate regression to assess the interaction between composites and surface treatment methods. RESULTS: Means and standard deviations for the groups were: Sodium bicarbonate jet 11.27±2.78; burs 9.26±3.01; stone 7.95±3.67; aluminum oxide blasting 7.04±3.21; phosphoric acid 5.82±1.90; hydrofluoric acid 4.54±2.87, and without treatment 2.75±1.49. An increase of 1.94 MPa in shear bond strength was seen in Charisma groups. Silane agent application reduced the Charisma shear bond strength by 0.68 Mpa, but increased Durafill means for bicarbonate blasting (0.83), burs (0.98) and stone drilling (0.46). CONCLUSION: The sodium bicarbonate blasting, burs and stone drilling methods produced adequate shear bond strength and may be suitable for clinical use. The Charisma micro hybrid resin composite showed higher shear bond means than Durafill micro particle composite.
8
Ávila, Gisseli Bertozzi, Sergio Candido Dias, Mariana Lima da Costa Valente, José Augusto Marcondes Agnelli e Andréa Candido dos Reis. "Color stability evaluation of micro hybrid composite resins submitted to accelerated artificial aging". Clinical and Laboratorial Research in Dentistry 21, n. 4 (31 dicembre 2015): 227. http://dx.doi.org/10.11606/issn.2357-8041.clrd.2015.128882.
Testo completoAbstract (sommario):
Objective: The aesthetics of dental materials is extremely important for the success of oral rehabilitation. Thus, in the present study we evaluated the color stability and the surface degradation of three micro hybrid composite resins after accelerated artificial aging process (AAA). Methods: Were prepared 24 specimens (n=8) for each material: Solidex, Artglass and Cesead, dimensions of Ø 15 mm by 2 mm in thickness. The samples were subjected to color analysis, before and after AAA, in a spectrophotometer according to the CIE L*a*b* parameters, and a sample of each material, was selected for morphological evaluation under scanning electron microscopy (SEM). The data were submitted to one-way ANOVA and Tukey test (α=0.05). Results: Artglass showed higher stability regarding the presence of red and yellow (p<0.05) when subjected to the AAA and fewer of these pigments (p<0.05) when compared to the Cesead and Solidex, which showed the highest luminance stability (p<0.05). ΔE Cesead was the most unstable (p<0.05). All resins analyzed by SEM showed superficial degradation when submitted to the AAA, mainly in resin Cesead. Conclusion: All materials analyzed demonstrate color change and surface degradation, Cesead resin showed the worse results.
9
Arigbede, Abiodun Olabisi, Bukola Folasade Adeyemi e Omowumi Femi-Akinlosotu. "Relative biocompatibility of micro-hybrid and nano-hybrid light-activated composite resins". Journal of Dental Research, Dental Clinics, Dental Prospects 11, n. 1 (15 marzo 2017): 1–6. http://dx.doi.org/10.15171/joddd.2017.001.
Testo completo
10
H. A, Omokhua, Sede M. A e Enabulele J. E. "Clinical evaluation of the functional performance of organically modified ceramics (ormocers), nanohybrid, and microhybrid composite in permanent posterior teeth restorations." Ghana Dental Journal 19 (21 giugno 2022): 52–59. http://dx.doi.org/10.4314/gdj.v19i1.8.
Testo completoAbstract (sommario):
Background : In recent times, resin-based direct composite restorations have become a routine and well-established dental practice, meeting the demands for aesthetics and minimally invasive restorative care. The use of resin-based composite resin for defects in posterior teeth is on the rise. A good knowledge of adhesives, composite resins, and polymerization kinetics is required to effectively use composite in patient care.Objective : To compare the functional clinical performance of an ormocer and a nanohybrid to that of a traditional microhybrid composite in posterior teeth restorations.Material and Method : Patients with at least three carious lesions which required replacement (Class Ι and/or Class ΙΙ), each with an opposing tooth, were enrolled in this study. A total of 105 restorations were placed, 35 for each. The materials used for this study included an ormocer-based composite, a nanohybrid resin composite, and a micro-hybrid resin composite. One operator placed all the restorations according to the manufacturers’ instructions. Each restoration is finished and polished immediately after placement. The patient returned for follow-up evaluation at one(1 )month, three (3 )months,six6 months, and 12 months. Two independent examiners calibrated with the web-based training called e-calib performed the evaluation using the FDI Criteria.Results : A total of 105 resin composite restorations, 35 restorations for each of the study materials, were placed in 35 subjects, with a female to male ratio of 4.8:1. The subject recall rate was 100%. All ormocer, nanohybrid, and micro-hybrid resin composites restorations recorded 100% clinically excellent scores from baseline to 3 months for all parameters. Most of the study materials showed a decrease from 100% clinically excellent scores, with a few recordings clinically good at 12 months. At least one restoration of each material experienced a deterioration of the parameters, fracture, retention of materials, and proximal anatomic form.The functional clinical performance of ormocer admira (voco), Tetric EvoCeram (Ivoclar Vivadent), a Nanohybrid, and tetric Ceram (Excite), a micro-hybrid were satisfactory in the restorations of carious posterior permanent teeth. The majority of the restorations maintained clinically excellent scores from 1 month to 12 months. There was, however, no record of scores 3, 4, or 5 by any of the test materials throughout the study.Conclusion : The functional clinical performance of ormocer admira (voco), Tetric EvoCeram (Ivoclar Vivadent), a Nanohybrid, and tetric Ceram (Excite) micro-hybrid were satisfactory in the restorations of posterior permanent teeth restorations.
11
Micali, Bianca, e Roberta Tarkany Basting. "Effectiveness of composite resin polymerization using light-emitting diodes (LEDs) or halogen-based light-curing units". Brazilian Oral Research 18, n. 3 (settembre 2004): 266–70. http://dx.doi.org/10.1590/s1806-83242004000300016.
Testo completoAbstract (sommario):
The clinical performance of composite resins is greatly influenced by the quality of the light-curing unit used. The aim of this study was to compare the efficiency of a commercial light-emitting diode (LED) with that of a halogen-based light-curing unit by means of dye penetration of a micro hybrid composite resin. The composite resin evaluated was Filtek Z250 (3M Dental). The composite was filled into acrylic moulds that were randomly polymerized for 40 seconds by each of the light-emitting systems: light-emitting diode Ultraled (Dabi Atlante) or halogen light Degulux (Degussa Hüls) curing units. Immediately after polymerization, each specimen was individually immersed in 1 ml of 2% methylene blue solution at 37°C ± 2°C. After 24 hours, the specimens were rinsed under running distilled water for 1 minute and stored at 37°C ± 2°C at relative humidity for 24 hours. The composite resins were removed from the moulds and individually triturated before being immersed in new test tubes containing 1 ml of absolute alcohol for 24 hours. The solutions were filtered and centrifuged for 3 minutes at 4,000 rpm and the supernatant was used to determine absorbance in a spectrophotometer at 590 nm. To verify the differences between groups polymerized by LED or halogen light t-test was applied. No significant differences were found between composite resins light-cured by LED or halogen light-curing unit (p > 0.05). The commercially LED-based light-curing unit is as effective to polymerize hybrid composite resins as the halogen-based unit.
12
Fejjeri-Mezghanni, Meriem. "Silorane versus methacrylate composites: A comparative study of the micro-leakage". New Trends and Issues Proceedings on Advances in Pure and Applied Sciences, n. 9 (9 gennaio 2018): 58–65. http://dx.doi.org/10.18844/gjapas.v0i9.3017.
Testo completoAbstract (sommario):
This in vitro study aimed to evaluate the micro-leakage at the occlusal and cervical margins in class II cavities in permanent molars restored with a low shrink silorane resin composite (Filtek P90) applied with or without etching and two methacrylate-based composite resins (valux plus and Amelogen® plus). Two standardised class II box cavities were prepared in proximal surfaces of 60 sound non-fluorotic permanent molars which were divided into three groups of 20 each according to the type of composite. Group I: silorane-based composite (Filtek P90) in the mesial cavity and methacrylate-based microhybrid composite (Adper single bond 2/valux plus) in the distal cavity, Group II: silorane-based composite in the mesial cavity and silorane-based composite with previous etching in the distal cavity, and Group III: silorane-based composite in the mesial cavity and methacrylate-based micro-hybrid composite (PQ1 /Amelogen plus) in the distal cavity. The samples underwent an artificial aging with thermocycling. Root apices were sealed with transparent orthodontic resin and coated with transparent varnish except 1 mm around the restoration. The specimens were immersed in 1% methylene blue solution at room temperature for 48 hour. The samples were sectioned longitudinally in the mesiodistal direction and evaluated under a stereomicroscope at 20X. Scoring was done according to the depth of methylene blue penetration into the cavities. Statistical analysis of the data was performed using SPSS 17.0 software. Silorane-based composite resin showed less micro-leakage than the methacrylate-based composites. Etching improved the sealing ability of silorane restorations. Silorane-based composite preceded by etching had less micro-leakage among the other materials used in this in vitro study. Keywords: Silorane, methacrylate based composite, sealing, micro-leakage, class II cavity
13
Wulandari, Erawati, Faiqatin Cahya Ramadhani e Nadie Fatimatuzzahro. "Potential of 5% tamarind extract gel as an etching agent: tensile strength and scanning electron microscope (SEM) evaluation". Dental Journal (Majalah Kedokteran Gigi) 53, n. 1 (31 marzo 2020): 16. http://dx.doi.org/10.20473/j.djmkg.v53.i1.p16-19.
Testo completoAbstract (sommario):
Background: Acid etching is a stage in obtaining bonds between composites and enamel. The application of acid to the enamel surface, however, can cause dissolution of hydroxyapatite and demineralisation of the enamel surface. Phosphoric acid, a strong acid, is an etching material that can reduce enamel hardness. Excessively reducing hardness can interfere with attachment to the restorative material. One medicinal plant that can be used as an alternative material in acid etching is tamarind. Purpose: This study aims to determine the effect of 5% tamarind extract gel on the tensile strength of composite resins. Methods: This is an experimental research study with a post-test-only control-group design. The study used 14 mandibular incisors. The labial part of the incisor was prepared using a diamond fissure bur with a diameter of 4 mm and a depth of 2 mm. The control group was then etched with 37% phosphoric acid gel, while the experimental group was etched with 5% tamarind extract gel. Bonding resins and micro-hybrid composite resins were applied, based on the manufacturers’ instructions. Next, a tensile strength test and seeing formation resin tags by scanning electron microscope (SEM) were performed. Data were analysed using an independent t-test (p < 0.05). Results: The average tensile strength of composite resins in the group etched with 5% tamarind extract gel was the same as in the 37% phosphoric acid group (p > 0.05). SEM images also show that enamel etched with 5% tamarind extract gel produced a tag similar to that etched with 37% phosphoric acid gel. Conclusion: 5% tamarind extract as an etching material can generate tensile strength of composite resin and trigger formation of resin tags in the same way as 37% phosphoric acid.
14
Münchow, Eliseu A., Ana Cláudia A. Ferreira, Raissa M. M. Machado, Tatiana S. Ramos, Sinval A. Rodrigues-Junior e Cesar H. Zanchi. "Effect of Acidic Solutions on the Surface Degradation of a Micro-Hybrid Composite Resin". Brazilian Dental Journal 25, n. 4 (2014): 321–26. http://dx.doi.org/10.1590/0103-6440201300058.
Testo completoAbstract (sommario):
Composite resins may undergo wear by the action of chemical substances (e.g., saliva, alcohol, bacterial acids) of the oral environment, which may affect the material's structure and surface properties. This study evaluated the effect of acidic substances on the surface properties of a micro-hybrid composite resin (Filtek Z-250). Eighty specimens were prepared, and baseline hardness and surface roughness (KMN0 and Ra0, respectively) were measured. The specimens were subjected to sorption (SO) and solubility (SL) tests according to ISO 4049:2009, but using different storage solutions: deionized water; 75/25 vol% ethanol/water solution; lactic acid; propionic acid; and acetic acid. The acids were used in two concentrations: PA and 0.02 N. pH was measured for all solutions and final hardness (KMN1) and surface roughness (Ra1) were measured. Data were analyzed with paired t-tests and one-way ANOVA and Tukey's test (a=5%). All solutions decreased hardness and increased the Ra values, except for the specimens stored in water and 0.02 N lactic acid, which maintained the hardness. All solutions produced similar SO and SL phenomena, except for the 0.02 N lactic acid, which caused lower solubility than the other solutions. Ethanol showed the highest pH (6.6) and the 0.02 N lactic acid the lowest one (2.5). The solutions affected negatively the surface properties of the composite resin; in addition, an acidic pH did not seem to be a significant factor that intensifies the surface degradation phenomena.
15
Arruda, Marcela Monice, Marina Augusto Toppino, Gabriela Monteiro Barbosa, Hilton Túlio Costi, Cecy Martins Silva e Jesuína Lamartine Nogueira Araújo. "Effect of Fluoride Gels on the Surface Roughness of Different Composite Resins". Open Dentistry Journal 14, n. 1 (15 ottobre 2020): 474–81. http://dx.doi.org/10.2174/1874210602014010474.
Testo completoAbstract (sommario):
Background: The pH of fluoride gels influences the roughness of composite resins, which affects their clinical durability. Objective: To evaluate the effect of fluoride gels (1.23% acidified phosphate fluoride and neutral fluoride) on the morphology of different composite resins after finishing and polishing. Methods: We prepared sixty specimens with a diameter of 5 mm and a height of 2 mm. The specimens were then divided into six groups (n = 10), according to the type of composite resin (Z250 micro-hybrid (Z), Filtek Z350 XT nanoparticles (XT), and Tetric N-Ceram nano-hybrid (TC)) and fluoride gel treatment (1.23% acidified phosphate (APF) or neutral fluoride (NF)) to measure surface roughness (Ra). The material was light-cured using an LED-curing unit (Elipar Freelight Deep Cure-3M/ESPE) for 20 s with a light intensity of 1.200 mW/cm2. Ra measurements were performed before and after treatment with different fluoride gels using a rugosimeter (Mitutoyo SJ210). After Ra, we selected two samples from each group for evaluation using scanning electron microscopy. Data were analyzed using the Shapiro-Wilk, ANOVA, and Tukey tests, with a significance of 5%. Results: The average Ra before and after NF did not differ statistically. The average Ra values of the groups treated with APF showed statistically significant differences. The photomicrographs of the groups treated with NF were similar to those of the groups without fluoride treatment. The APF-treated groups showed significant morphological changes. Conclusion: NF did not promote changes in the morphology of the evaluated composite resins, in contrast to APF, which caused significant changes.
16
Gugelmin, Brenda Procopiak, Luiz Carlos Machado Miguel, Flares Baratto Filho, Leonardo Fernandes da Cunha, Gisele Maria Correr e Carla Castiglia Gonzaga. "Color Stability of Ceramic Veneers Luted With Resin Cements and Pre-Heated Composites: 12 Months Follow-Up". Brazilian Dental Journal 31, n. 1 (gennaio 2020): 69–77. http://dx.doi.org/10.1590/0103-6440202002842.
Testo completoAbstract (sommario):
Abstract The objective was to evaluate the color stability of ceramic veneers luted with resin cements and pre-heated composite resins (60oC) for 12 months, and determine the degree of conversion (DC) of the luting agents. Two resin cements (AllCem Veneer, light-cured (LRC) and AllCem, dual-cured (DRC)] and three composite resins [Z100 (MNCR-minifilled), Herculite Classic (MHCR-micro-hybrid) and Durafill (MCCR-microfilled)] were used for cementing 0.8-mm-thick lithium-silicate glass-ceramic laminates (Suprinity, shade B2-HT, Vita) on bovine enamel (n=10). The specimens were stored at 37oC in distilled water. CIELab parameters were determined at 24h after luting (baseline), 7, 30, 90, 180 days and 12 months. Three specimens were prepared for DC evaluation, performed by micro-Raman spectroscopy. Data were analyzed by ANOVA and Tukey’s test (a=5%). For ΔEab and ΔE00, there were significant differences for luting material (p<0.001), time (p<0.001), and double interaction (p<0.001). The groups cemented with MHCR (1 year), MCCR (90 days and 1 year) and MCCR-PH (1 year) were the ones with ΔE values greater than the acceptability threshold. All other groups maintained their ΔE lower than the acceptability threshold after 1 year in distilled water. Regarding DC, there were no significant differences (p=0.127) among the materials. Non-significant negative correlations were observed between the mean ΔEab and DC (R=-0.65) and ΔE00 and DC (R=-0.64). A significant positive correlation was observed mean ΔEab and ΔE00 (R=0.99). It was concluded that the different luting agents influenced the final color of the restorations. The heating of the composite resins did not affect their DC.
17
Saleem, Muhammad Zaheer, e Mohammad Akbar. "Review of the Performance of High-Voltage Composite Insulators". Polymers 14, n. 3 (21 gennaio 2022): 431. http://dx.doi.org/10.3390/polym14030431.
Testo completoAbstract (sommario):
In the present literature survey, we focused on the performance of polymeric materials encompassing silicone rubber (SiR), ethylene propylene diene monomer (EPDM) and epoxy resins loaded with micro, nano, and micro/nano hybrid fillers. These insulators are termed as composite insulators. The scope of the added fillers/additives was limited to the synthetic inorganic family. Special attention was directed to understanding the effect of fillers on the improvement of the thermal conductivity, dielectric strength, mechanical strength, corona discharge resistance, and tracking and erosion resistance performance of polymeric materials for use as high-voltage transmission line insulators. The survey showed that synthetic inorganic fillers, which include silica (SiO2) and hexagonal boron nitride (h-BN), are potential fillers to improve insulation performance of high-voltage insulators. Furthermore, nano and micro/nano filled composites performed better due to the better interaction between the filler and polymer matrix as compared to their only micro- or nano filled counterparts. Finally, some aspects requiring future work to further exploit fillers are identified and discussed.
18
Ghiorghe, Cristina Angela, Andra Claudia Gamen, Tiberiu Tirca, Sorin Andrian, Anca Melian, Galina Pancu e Mihaela Salceanu. "Laser Therapy Evaluation in Complications of Restorations by Total-Etch Technique". Revista de Chimie 69, n. 4 (15 maggio 2018): 921–25. http://dx.doi.org/10.37358/rc.18.4.6228.
Testo completoAbstract (sommario):
The aim of this study was to evaluate the efficiency of laser therapy in post-operative sensitivity by Visual Analogue Scale (VAS) to the 57 patients after restoration with two different resins composite. In the first group (28 patients, 30 teeth) it was restored the cavity class I Black with micro-hybrid composite Filtek Z250 - Adper Single Bond (3M/ESPE). In the second group (29 patients, 30 teeth) it was restored the cavity class III Black with nano-hybrid composite Ceram X One Sphere Tec-Prime and Bond One (Etch&Rinse) (Dentsply). The restorative treatments were performed by the same practitioner on posterior and anterior teeth diagnosed with mid-sized chronic carious lesions. Total etch (etch and rinse) strategy of adhesion was used for both composite resins. The laser treatment was performed in 2 sessions at 48 hours and after 7 days, for both study groups using laser Whitening Lase II (DMC Dental). Mean scores for VAS indices decreased significantly at 48 hours and 7 days, following laser treatment for all the investigated parameters (materials, sex, age) (p [ 0.05).
19
Chaturvedi, S., D. Barve, P. Dave, M. Gulve, S. Saquib, G. Das e M. Sibghatullah. "Assessment of microhardness and color stability of micro-hybrid and nano-filled composite resins". Nigerian Journal of Clinical Practice 24, n. 10 (2021): 1499. http://dx.doi.org/10.4103/njcp.njcp_632_20.
Testo completo
20
Kanehira, Masafumi, Werner J. Finger, Naohiko Iwasaki, Natthavoot Koottathape e Hidekazu Takahashi. "Morphological Features of Composite Resin Surfaces after Two- and Three-Body Wear Simulation". World Journal of Dentistry 3, n. 3 (2012): 221–28. http://dx.doi.org/10.5005/jp-journals-10015-1160.
Testo completoAbstract (sommario):
ABSTRACT Purpose To investigate morphological surface features of different composite resins after 30,000 sliding wear cycles under two- and three-body wear action. Materials and methods The morphology of worn surfaces of four nanofiller containing composite resins, Filtek Supreme XT (FIL), MI Flow (MFL), Venus Diamond (VED) and Venus Pearl (VEP) were investigated and compared with three conventional composites as references, microfilled Durafill VS (DUR), microhybrid Filtek Z250 (Z250) and hybrid-type Clearfil AP-X (APX). Plane surfaces of the polymerized and water-saturated materials (n = 5) were tested in a custom-built pin-on-disk wear machine fitted with a zirconia ball, 4 mm in diameter, serving as the antagonist ‘cusp’ and loading the specimen at 15° angulation for 3.7 mm long sliding paths (50 N load, 1.2 Hz, 30,000 cycles) either in water, simulating two-body wear, or in slurries of PMMA beads or poppy seed, simulating three-body wear. Random samples of each material were selected and sputter-coated with gold for inspection of the wear patterns using scanning electron microscopy. Results Under two-body wear action all materials showed cracking as indicator of fatigue. MFL and VEP with prepolymer particles were least affected. Similarly, surfaces after three-body wearing with PMMA bead slurry revealed crack formation for five of the composites tested. The micro-hybrid Z250 and the nanofilled FIL displayed compressed and shallow delaminated areas. With poppy seed slurry as the third-body medium DUR was deeply destructed. Also the nanohybrid VED with a small fraction of up to 20 ƒÝm large ground glass fillers revealed deep cracks, whereas small delamination areas characterized the hybrid composite APX. Z250 as well as FIL, MFL and VEP were smoothly abraded without showing signs of cracking or delamination. Conclusion Composite resin surfaces, worn under two-body sliding showed mainly crack formation as an expression of fatigue. Similarly, three-body abrasion with a PMMA bead slurry revealed surface cracks to various extent and delamination, which is also an expression of fatigue related damage. With fine-ground poppy seed slurry only the microfilled composite with large prepolymer particles showed catastrophic failure. In all other cases the small poppy seed fragments in the slurry abraded the surfaces, removing polymer or fine particle loaded matrix uniformly. Supposedly, poppy seed slurry is a suitable third-body medium, simulating occlusal wear produced by food, rich in fibers or grain. How to cite this article Koottathape N, Takahashi H, Iwasaki N, Kanehira M, Finger WJ. Morphological Features of Composite Resin Surfaces after Two- and Three-Body Wear Simulation. World J Dent 2012;3(3):221-228.
21
Al-Taie, Dr Lamis A., Dr Anas FM Al-Aubaydi e Dr Abdulla MW Al-Shamma. "The Effect of Pepsi Cola Beverage on Surface Roughness of Two Composite Resins (In Vitro study)". Mustansiria Dental Journal 7, n. 1 (18 marzo 2018): 9–14. http://dx.doi.org/10.32828/mdj.v7i1.360.
Testo completoAbstract (sommario):
An acidic environment causes surface changes of resin composites. Filler particlesize and filler distribution also have a direct effect on these surface changes. This invitro study evaluated the influence of Pepsi Cola drink on the surface roughness ofComposan LCM and Composan Ceram over time. Sixteen disc shaped specimens(10mm diameter, 2mm thickness) of each resin composite were fabricated, therebyforming two groups (n= 8). Surface roughness (Ra) was analyzed after 24 hrs beforeexposure to beverage. The specimens were submitted to a five minutes immersion inPepsi Cola three times daily interrupted by immersion in deionized distilled water (37C˚). Surface roughness measurements were done at 10, 30, and 60 days intervals. Datawere submitted to paired t-test. There was a statistically highly significant (p <0.001)increase in surface roughness values of the tested composites after 30 days and 60days immersion in Cola drink. Composan LCM exhibited a significantly (p <0.05)higher surface roughness values than Composan Ceram.The surface roughness of the composite materials are significantly affected byexposure to acidic drink over time, highly filled micro hybrid composites with smallfiller particle size are significantly more resistant to acid erosion.
22
Wu, Yu‐Ren, Chin‐Wei Chang, Kai‐Chi Chang, Dan‐Jae Lin, Chia‐Ling Ko, Hui‐Yu Wu e Wen‐Cheng Chen. "Effect of micro‐/nano‐hybrid hydroxyapatite rod reinforcement in composite resins on strength through thermal cycling". Polymer Composites 40, n. 9 (15 febbraio 2019): 3703–10. http://dx.doi.org/10.1002/pc.25232.
Testo completo
23
Zemskova, L. A., D. H. Shlyk e N. N. Barinov. "Hybrid Sorbents for Removal of Arsenic". Kompleksnoe ispolʹzovanie mineralʹnogo syrʹâ/Complex Use of Mineral Resources/Mineraldik shikisattardy Keshendi Paidalanu 320, n. 1 (5 gennaio 2022): 32–41. http://dx.doi.org/10.31643/2022/6445.04.
Testo completoAbstract (sommario):
The paper analyzes data on the removal of arsenic by sorption methods using materials that have prospects for large-scale application in water treatment. These materials include transition metal oxides in the micro- and nano-dimensional form, including those in the composition of composite materials with inorganic matrices, or hybrid sorbents in the composition with polymer resins or natural biopolymers. Examples of the use of composite (hybrid) sorbents for the removal of arsenic from solutions with low concentrations (at the level of MPC) are given. The objective of this article was to sum the up-to-date information about the most important features of chitosan-containing and chitosan-carbon materials we developed in view their use in arsenic removal processes at low concentrations to concentrations that meet WHO requirements. The paper presents data on the sorption properties of Mo-containing activated carbon fibers and chitosan-carbon composite materials towards arsenic (V) when it is extracted from bidistilled and tap water under static and dynamic conditions. The factors of the different behavior of the sorbents depending on the form of a biopolymer deposited on the fiber and the stability of the sorbents during the sorption of arsenic are discussed.
24
Nadig, RoopaR, Arpita Deb, Veena Pai e Aesha Akhtar. "Evaluation of microleakage of micro hybrid composite resins versus chitosan-incorporated composite resins when restored in class v cavities using total etch and self-etch adhesives: An in vitro study". Contemporary Clinical Dentistry 12, n. 4 (2021): 346. http://dx.doi.org/10.4103/ccd.ccd_414_20.
Testo completo
25
Camilotti, Veridiana, Anna Caroliny Detogni, Gláucia Maria Bovi Ambrosano, Márcio José Mendonça, Julio Katuhide Ueda e Mário Fernando De Goes. "Effect of acidic solutions present in the diet on the surface roughness of microhybrid composite resins". Research, Society and Development 11, n. 4 (24 marzo 2022): e46111426588. http://dx.doi.org/10.33448/rsd-v11i4.26588.
Testo completoAbstract (sommario):
The objective of this study was to evaluate in vitro the roughness and surface morphology of composite resins (CRs) stored for 180 days in acidic solutions present in the diet. Three micro-hybrid composite resins were used in this study (Charisma, Opallis, and Esthet-X). Fifty-one specimens were made of each material with 4 mm in diameter and 2 mm thick with the aid of an elastomer matrix. After photoactivation for 40 seconds (Elipar Free-Light / 3M ESPE), the specimens were stored in distilled water for 24 hours at 37ºC for subsequent surface polishing with Soft Lex / 3M ESPE discs in fine and extra-fine granulation. Then, the specimens were dried with absorbent paper and the surface roughness was measured using a rugosimeter. The specimens were then randomly divided into five groups (n=10) according to the tested solutions: DW - Distilled water (pH 5.30); RW - Red Wine / Trapiche Syha Ind. Argentina red wine (pH 3.68); CK – Coke / Coca Cola Co. (pH 2.73), OJ - Orange juice / Purity Cocamar (pH 3.58) and LBS - lactate buffer solution (pH 2.74). The tested solutions were changed daily. The surface roughness test was repeated after 15, 90 and 180 days of immersion. The average values of surface roughness were submitted to LSmeans analysis and Tukey-Kramer test, at a significance level of 5%. The results of surface roughness revealed that all CRs showed a significant increase in the roughness values over time for all tested solutions.
26
Khan, Abdul Samad. "Effect of Ultrasonic Vibration on Structural and Physical Properties of Resin-Based Dental Composites". Polymers 13, n. 13 (23 giugno 2021): 2054. http://dx.doi.org/10.3390/polym13132054.
Testo completoAbstract (sommario):
This study aimed to investigate the influence of ultrasonic heat before photo-polymerization on the structural and physical properties of dental composites. Commercially available bulk-fill, nano-hybrid, micro-hybrid, and flowable composites were used. The samples were divided into three groups i.e., (i) without ultrasonic activation, (ii) ultrasonic activation at 15 Hz for 30 s, and (iii) ultrasonic activation at 15 Hz for 60 s. The degree of conversion percentage (DC%) and structural changes were evaluated with Fourier transform infrared spectroscopy. The presence of voids in restored tooth cavities were investigated with micro-computed tomography. The statistical analysis was performed using a one-way analysis of variance (ANOVA) post hoc Tukey’s test. The DC% was significantly increased with ultrasonic application in all groups except for flowable composites, whereby flowable composite showed a significant increase with 30 s ultrasonic activation only. The highest DC% was observed in 60 s ultrasonically activated nano-hybrid and micro-hybrid composites. The voids were reduced linearly with ultrasonic application in flowable and bulk-fill composites; however, non-linear behavior was observed with micro-hybrid and nano-hybrid composites, whereby the difference was significant within the groups. The frequency and time of the ultrasonic application is an important factor to consider and can be used to preheat composites before clinical application.
27
D., Sarukasan*, Thirumavalavan K., Prahadeeswaran M e Muruganandhan R. "Fabrication and Mechanical Characterization of Jute-Coir Reinforced Unsaturated Polyester Resin Hybrid Composites with Various Fiber Size using Compression Moulding Technique". International Journal of Recent Technology and Engineering 10, n. 1 (30 maggio 2021): 233–41. http://dx.doi.org/10.35940/ijrte.a5934.0510121.
Testo completoAbstract (sommario):
Fiber reinforced composites plays major role in improving the strength of various applications in current trends. Based on these trends the combination of natural jute/coir fiber hybrid composite of different size of fiber length was examined in this study. The hybrid fiber composite was fabricated by compression moulding technique by impregnating jute fiber and coir fiber with unsaturated polyester resin, Cobalt octoate and methyl-ethyl-ketone peroxide as accelerator and catalyst. Then the prepared mould placed into the oven to dry for 4 hrs. at 50°C beneath closely to vacuum condition then convert the cured mould to the hot press initially for 1 hr at 105°C under 84 bar pressure until while squeeze out the excess resin, then it was cooled in cold press under constant pressure of 275 bar pressure for 15 min to prevent the warpage of hybrid composites. The micro hardness, tensile, flexural, impact strength of hybrid composite was carried out and the morphology of the composites was evaluated and compared. The test results of the hybrid composite were analyzed by one way ANOVA analysis technique and it shows significant difference among the groups.
28
Abdelaziz, Khalid M., Shugufta Mir, Shafait Ullah Khateeb, Suheel M. Baba, Saud S. Alshahrani, Eman A. Alshahrani e Zahra A. Alsafi. "Influences of Successive Exposure to Bleaching and Fluoride Preparations on the Surface Hardness and Roughness of the Aged Resin Composite Restoratives". Medicina 56, n. 9 (16 settembre 2020): 476. http://dx.doi.org/10.3390/medicina56090476.
Testo completoAbstract (sommario):
Background and Objectives: Surfaces of composite restorations are adversely affected upon bleaching and topical fluoride application. Such a procedure is normally carried out in the presence of restorations already serving in a different oral environment, although previous in vitro studies only considered the freshly-prepared composite specimens for assessment. The current study accordingly aimed to evaluate both the surface hardness and roughness of aged composite restoratives following their successive exposure to bleaching and topical fluoride preparations. Materials and Methods: Disc specimens were prepared from micro-hybrid, nano-filled, flowable and bulk-fill resin composites (groups 1–4, n = 60 each). All specimens were subjected to artificial aging before their intermittent exposure to surface treatment with: none (control), bleach or topical fluoride (subgroups 1–3, n = 20). All surface treatments were interrupted with two periods of 5000 thermal cycles. Specimens’ surfaces were then tested for both surface hardness (Vickers hardness number (VHN), n = 10) and roughness (Ra, n = 10). The collected VHNs and Ras were statistically analyzed using two-way ANOVA and Tukey’s comparisons at α = 0.05 to confirm the significance of differences between subgroups. Results: None of the tested composites showed differences in surface hardness and roughness between the bleached and the non-treated specimens (p > 0.05), but the bleached flowable composite specimens only were rougher than their control (p < 0.000126). In comparison to the control, fluoride treatment not only reduced the surface hardness of both micro-hybrid (p = 0.000129) and flowable (p = 0.0029) composites, but also increased the surface roughness of all tested composites (p < 0.05). Conclusion: Aged composite restoratives provide minimal surface alterations on successive bleaching and fluoride applications. Flowable resin composite is the most affected by such procedures. Although bleaching seems safe for other types of composites, the successive fluoride application could deteriorate the aged surfaces of the tested resin composites.
29
Inam, Fawad, Doris W. Y. Wong, Manabu Kuwata e Ton Peijs. "Multiscale Hybrid Micro-Nanocomposites Based on Carbon Nanotubes and Carbon Fibers". Journal of Nanomaterials 2010 (2010): 1–12. http://dx.doi.org/10.1155/2010/453420.
Testo completoAbstract (sommario):
Amino-modified double wall carbon nanotube (DWCNT-NH2)/carbon fiber (CF)/epoxy hybrid micro-nanocomposite laminates were prepared by a resin infusion technique. DWCNT-NH2/epoxy nanocomposites and carbon fiber/epoxy microcomposites were made for comparison. Morphological analysis of the hybrid composites was performed using field emission scanning electron microscope. A good dispersion at low loadings of carbon nanotubes (CNTs) in epoxy matrix was achieved by a bath ultrasonication method. Mechanical characterization of the hybrid micro-nanocomposites manufactured by a resin infusion process included three-point bending, mode I interlaminar toughness, dynamic mechanical analysis, and drop-weight impact testing. The addition of small amounts of CNTs (0.025, 0.05, and 0.1 wt%) to epoxy resins for the fabrication of multiscale carbon fiber composites resulted in a maximum enhancement in flexural modulus by 35%, a 5% improvement in flexural strength, a 6% improvement in absorbed impact energy, and 23% decrease in the mode I interlaminar toughness. Hybridization of carbon fiber-reinforced epoxy using CNTs resulted in a reduction in and dampening characteristics, presumably as a result of the presence of micron-sized agglomerates.
30
Motoc Luca, Dana. "Hybrid Particle/Fiber Polymer Based Composites Analysis Based on DMA Data vs. Material Property Predictions". Applied Mechanics and Materials 659 (ottobre 2014): 101–6. http://dx.doi.org/10.4028/www.scientific.net/amm.659.101.
Testo completoAbstract (sommario):
The paper aims a comparison with respect to the dynamic mechanical properties of few hybrid polymer based composite architectures based on experimental data against micro-mechanical models based numerical predictions. The hybrid polymer based composites considered were particle-fiber combinations reinforced within an unsaturated polyester resin to provide different architectures. Variations in storage modulus (E’), loss modulus (E’’) and damping factor (tan δ) with temperature increase and different particle volume fraction were investigated. Data comparison reveals the herein composite architectures’ performances over the benchmark and enables further insight into the material development and characterization issues.
31
Binhasan, Mashael, Abdulilah H. Solimanie, Khalid S. Almuammar, Ahmed R. Alnajres, Mai M. Alhamdan, Khold Al Ahdal, Yasser F. Alfaawaz, Khalid Ali, Fahim Vohra e Tariq Abduljabbar. "The Effect of Dentifrice on Micro-Hardness, Surface Gloss, and Micro-Roughness of Nano Filled Conventional and Bulk-Fill Polymer Composite—A Micro Indentation and Profilometric Study". Materials 15, n. 12 (20 giugno 2022): 4347. http://dx.doi.org/10.3390/ma15124347.
Testo completoAbstract (sommario):
The aim of the present study was to evaluate the effect of brushing with two whitening dentifrices (Colgate Optic White (COW) and Colgate Optic White Charcoal (COC)) on surface gloss, micro-roughness, and micro-hardness of nanostructured hybrid conventional (Z350) and bulk-fill (Tetric N Ceram bulk-fill) polymer composite. In total, 96 disk samples using two nano-hybrid composite polymers (Z350 and Tetric N Ceram Bulk-fill) were prepared. All specimens were exposed to two different dentifrices (COW and COC), resulting in four main subgroups in the study. Specimens were assessed for surface gloss, micro-roughness (Ra), and micro-hardness using standardized methodology. Means and standard deviations of properties compared using paired t-test, one-way and two-way ANOVA, and post hoc test. The presence of dentifrices did not show any significant difference in micro-hardness values of Z350 (p > 0.05), whereas micro-hardness of bulk-fill composite significantly reduced on dentifrices exposure (p ≤ 0.05). Bulk-fill polymer composite showed significant reduction in gloss after dentifrice exposure (p < 0.05), however, Z350 showed no significant loss of gloss due to dentifrices (p > 0.05). A significant increase in Ra was observed for both resin materials after exposure to dentifrices (COC and COW). Conventional resin composite (Z350) showed comparable surface hardness and gloss before and after dentifrice exposure, however, micro-roughness increased significantly due to dentifrice exposure. Bulk-fill resin (Tetric N Ceram) showed significant loss of micro-hardness and gloss and increase in micro-roughness on dentifrice exposure. Conventional nano-hybrid composite polymer showed better durability in resisting loss of surface properties compared to bulk-fill resin polymer in the present experiment.
32
Wu, Liwei, Xiaojun Sun, Chunjie Xiang, Wei Wang, Fa Zhang, Qian Jiang, Youhong Tang e Jia-Horng Lin. "Short Beam Shear Behavior and Failure Characterization of Hybrid 3D Braided Composites Structure with X-ray Micro-Computed Tomography". Polymers 12, n. 9 (26 agosto 2020): 1931. http://dx.doi.org/10.3390/polym12091931.
Testo completoAbstract (sommario):
Three-dimensional braided composite has a unique spatial network structure that exhibits the characteristics of high delamination resistance, damage tolerance, and shear strength. Considering the characteristics of braided structures, two types of high-performance materials, namely, aramid and carbon fibers, were used as reinforcements to prepare braided composites with different hybrid structures. In this study, the longitudinal and transverse shear properties of 3D braided hybrid composites were tested to investigate the influences of hybrid and structural effects. The damage characteristics of 3D braided hybrid composites under short beam shear loading underwent comprehensive morphological analysis via optical microscopy, water-logging ultrasonic scanning, and X-ray micro-computed tomography methods. It is shown that the shear toughness of hybrid braided composite has been improved at certain degrees compared with the pure carbon fiber composite under both transverse and longitudinal directions. The hybrid braided composites with aramid fiber as axial yarn and carbon fiber as braiding yarn exhibited the best shear toughness under transverse shear loading. Meanwhile, the composites with carbon fiber as axial yarn and aramid fiber as braiding yarn demonstrated the best shear toughness in the longitudinal direction. Due to the different distribution of axial and braiding yarns, the transverse shear property of hybrid braided structure excels over the longitudinal shear property. The failure modes of the hybrid braided composite under the two loading directions are considerably different. Under transverse loading, the primary failure mode of the composites is yarn fracture. Under longitudinal loading, the primary failure modes are resin fracture and fiber slip. The extensive interfacial effects and the good deformation capability of the hybrid braided composites can effectively prevent the longitudinal development of internal cracks in the pattern, improving the shear properties of braided composites.
33
Wang, Genwei, Han Zhao, Jinbo Bai e Ya-Pu Zhao. "Fabrication and Mechanical Properties of a Micro/Nanoscale Hybrid Composite". International Journal of Nonlinear Sciences and Numerical Simulation 13, n. 2 (1 aprile 2012): 153–57. http://dx.doi.org/10.1515/ijnsns.2011.109.
Testo completoAbstract (sommario):
Abstract Microscale SiC particles with multiwalled carbon nanotubes grow on were filled in epoxy resin to construct multiscale hybrid composite. Static and dynamic compressive responses of composites were investigated. A dynamic experimental technique, split Hopkinson press bar (SHPB), was introduced to study the constitutive laws of materials at high strain rates. SEM observations show good dispersion of carbon nanotubes and SiC particles, but bad link between SiC particles and carbon nanotubes exists. Experimental results of static and dynamic tests verify that increase of strength happens with SiC/CNT as reinforcement Increment of strength under dynamic loading is bigger than under static loading.
34
Tolosa, Maria Cecília Caldas Giorgi, Luís Alexandre Maffei Sartini Paulillo, Marcelo Giannini, Alex José Souza dos Santos e Carlos Tadeu dos Santos Dias. "Influence of composite restorative materials and light-curing units on diametrical tensile strength". Brazilian Oral Research 19, n. 2 (giugno 2005): 123–26. http://dx.doi.org/10.1590/s1806-83242005000200009.
Testo completoAbstract (sommario):
The aim of this study was to evaluate the diametrical tensile strength (DTS) of three light-curing photo-activated composites with two different light curing units (LCU). Three types of dental restorative composites were used in this study: micro filled A110 (3M Espe); P60 (3M Espe) for posterior restorations, and micro-hybrid Charisma (Heraeus-Kulzer). The two LCUs were: halogen light (HAL) (Degulux, Degussa) and blue light emitting diode (LED) (Ultrablue, DMC). Resin composite specimens were inserted incrementally into a Teflon split mold meas-uring 3 mm in depth and 6 mm in internal diameter, and cured using either LCU (n = 10). Specimens were placed into a dark bottle containing distilled water at 37°C for 7 days. DTS tests were performed in a Universal Testing Machine (0.5 mm/min). Data were submitted to two-way ANOVA and Tukey's test. Results were (MPa): A110/HAL: 276.50 ± 62.94ª; A110/LED: 306.01 ± 65.16ª; P60/HAL: 568.29 ± 60.77b and P60/LED: 543.01 ± 83.65b; Charisma/HAL: 430.94 ± 67.28c; Charisma/LED: 435.52 ± 105.12c. Results suggested that no significant difference in DTS was obtained with LCUs for the same composite. However, resin composite restorative materials presented different DTS.
35
Odermatt, Reto, Matej Par, Dirk Mohn, Daniel B. Wiedemeier, Thomas Attin e Tobias T. Tauböck. "Bioactivity and Physico-Chemical Properties of Dental Composites Functionalized with Nano- vs. Micro-Sized Bioactive Glass". Journal of Clinical Medicine 9, n. 3 (12 marzo 2020): 772. http://dx.doi.org/10.3390/jcm9030772.
Testo completoAbstract (sommario):
Bioactive resin composites can contribute to the prevention of secondary caries, which is one of the main reasons for failure of contemporary dental restorations. This study investigated the effect of particle size of bioactive glass 45S5 on chemical and physical composite properties. Four experimental composites were prepared by admixing the following fillers into a commercial flowable composite: (1) 15 wt% of micro-sized bioactive glass, (2) 15 wt% of nano-sized bioactive glass, (3) a combination of micro- (7.5 wt%) and nano-sized (7.5 wt%) bioactive glass, and (4) 15 wt% of micro-sized inert barium glass. Hydroxyapatite precipitation and pH rise in phosphate-buffered saline were evaluated during 28 days. Degree of conversion and Knoop microhardness were measured 24 h after specimen preparation and after 28 days of phosphate-buffered saline immersion. Data were analyzed using non-parametric statistics (Kruskal–Wallis and Wilcoxon tests) at an overall level of significance of 5%. Downsizing the bioactive glass particles from micro- to nano-size considerably improved their capability to increase pH. The effect of nano-sized bioactive glass on degree of conversion and Knoop microhardness was similar to that of micro-sized bioactive glass. Composites containing nano-sized bioactive glass formed a more uniform hydroxyapatite layer after phosphate-buffered saline immersion than composites containing exclusively micro-sized particles. Partial replacement of nano- by micro-sized bioactive glass in the hybrid composite did not impair its reactivity, degree of conversion (p > 0.05), and Knoop microhardness (p > 0.05). It is concluded that downsizing bioactive glass particles to nano-size improves the alkalizing potential of experimental composites with no negative effects on their fundamental properties.
36
Bhudolia, Somen K., Goram Gohel, Durga Vasudevan, Kah Fai Leong e Pierre Gerard. "On the Mode I and Mode II Delamination Characteristics and Surface Morphological Aspects of Composites with Carbon-Thermoplastic Hybrid Fabrics and Innovative Liquid Thermoplastic Resin". Polymers 14, n. 19 (4 ottobre 2022): 4155. http://dx.doi.org/10.3390/polym14194155.
Testo completoAbstract (sommario):
In the current research, the delamination behavior under Mode I and Mode II loading for the hybrid carbon-thermoplastic fabrics in conjunction with novel liquid thermoplastic acrylic Elium® resin processable at ambient conditions was studied. The experimentation by incorporating doublers methodology, studying the performance under Mode I and Mode II loading, and understanding failure mechanisms using surface morphological fractography is deliberated. Hybrid Carbon-Ultra-high molecular weight polyethylene (UHMWPP)/Elium® composite has shown a 22.81% higher GIC and a 22.2% higher GIIC than Carbon-UHMWPP/Epoxy composite. On the contrary, the Carbon_Ultra-high molecular weight polypropylene (UHMWPE)/Elium® has shown an 11.11% higher Mode I critical energy release rate (GIC) and a 7.58% higher Mode II critical energy release rate (GIIC) than Carbon_UHMWPE/Epoxy composite. Hybrid fiber reinforced thermoplastic composites have shown severe plastic deformation of the matrix, rough fracture surface, and micro-cracks on the de-bonding surface, extensive fiber bridging, and crack branching which contributed to the improvement in the delamination behavior. Hybrid fiber architecture is also found to be detrimental by inducing crack arresting mechanisms including the tortuous crack path and the resin-rich pockets path due to the mismatch of the size of the fiber yarns.
37
Carvelli, Valter, Toru Fujii e Kazuya Okubo. "The effect of microfibrils cellulose modified epoxy on the quasi-static and fatigue behaviour of open hole carbon textile composites". Journal of Composite Materials 52, n. 24 (19 marzo 2018): 3365–80. http://dx.doi.org/10.1177/0021998318765623.
Testo completoAbstract (sommario):
The extensive experimental investigation aimed to assess the effects of hybrid epoxy resin with micro-fibrillated cellulose on tensile quasi-static and fatigue behaviour of open hole carbon plain weave composites. The hybridization of the matrix allowed an improved damage tolerance of the composite leading to increase of the quasi-static tensile strength and extension of the fatigue life. The enhanced mechanical performance of the notched composites was connected to the bridging effect of cellulose microfibrils preventing or delaying the cracks propagation in the matrix and along the fibres interface. The better distribution of the stress state was assessed by digital image correlation strain maps around the hole and the imparted fatigue damage was analysed by scanning electron microscope and X-ray micro-computed tomography visualizations.
38
Aleksandrova, Valeriya, Neshka Manchorova e Svetlin Aleksandrov. "TRIBOLOGICAL TESTS OF RESIN-BASED COMPOSITE MATERIALS: A DESIGN STUDY". Journal of IMAB - Annual Proceeding (Scientific Papers) 27, n. 2 (21 aprile 2021): 3700–3706. http://dx.doi.org/10.5272/jimab.2021272.3700.
Testo completoAbstract (sommario):
Objective: The objective of our research is to study the tribological behaviour of two types of commercially available resin-based composite materials. Material and method: An original experimental model for tribological studies of dental materials in standard test conditions was applied. Two types of resin-based composite materials indicated for the treatment of dental caries in the distal area were used: a micro-hybrid resin-based composite material (Gradia Direct posterior); packable resin-based composite material (Filtek P60). Metal alloy (Duceralloy C) was used for positive control. Total 18 test samples (n=9 for each material) were subject to: micro scratch resistance test in 1N, 5N, 9N mode; friction resistance "Ball-on-Flat" test at 120,000/240,000 cycles loaded on 50N. Results: When the maximum load was applied, Gradia Direct posterior had higher values of scratch depths (40, 23 µm) than Filtek P60 (25,13 µm). The micro-hybrid composite exhibited less wear resistance that decreased with increasing time and friction cycles (13 µm after 30 min/120,000 cycles; 18 µm ether 60 min/240,000 cycles). The examined surfaces of the test specimens were visualized by optical microscopy after micro scratch and friction test and by 3D profilometry of all tested samples after 240,000 wear cycles. Conclusion: Results in this field might clarify the mechanisms of wear and provide additional information on the expected changes in the studied materials in clinical practice.
39
Tamás, P., e T. Czigány. "Investigation of Mechanical Properties and Crack Propagation Behaviour of Hybrid Composites with Epoxy Resin Matrix". Materials Science Forum 729 (novembre 2012): 284–89. http://dx.doi.org/10.4028/www.scientific.net/msf.729.284.
Testo completoAbstract (sommario):
Mechanical properties, micro structure and crack propagation behaviour of different fabric reinforced mono and hybrid composites for materials of wind turbines have been investigated. Mechanical properties of different fabrics (glass, basalt and carbon) reinforced mono and hybrid composites with epoxy resin matrix have been compared. For characterization of materials tensile, three-point bending and single-edge notched tensile (SEN-T) tests with acoustic emission study were used and scanning electron microscope (SEM) pictures have been taken of the fracture surfaces of composite specimens. Similar behaviour of glass and basalt fibre reinforced composites was revealed by tensile and three-point bending tests. The satisfactory adhesion between fibre and matrix was shown by scanning electron microscope. The fibre-break was proven by the taken pictures to be the main failure mechanism. Results of mechanical tests were also confirmed by acoustic emission study. The crack propagation method of glass and basalt fabric reinforced composites is similar.
40
Salih, Dr Shatha Abdullah. "The effect of Light Emitting Diode and Sandwich technique on Pulp Temperature during Polymerization of Composite resin". Mustansiria Dental Journal 6, n. 1 (20 marzo 2018): 8–13. http://dx.doi.org/10.32828/mdj.v6i1.416.
Testo completoAbstract (sommario):
This in vitro study evaluated the effect of glass ionomer liner in limiting temperature rise during composite curing with Light Emitting Diode (LED cure unit) compare it with Conventional visible light-cure lamp.Twenty sound upper premolar teeth were used & on the buccal and palatal surfaces of them, a standardized class V cavity was prepared, 1mm occlusal to the cemento-enamel junction. Cavity dimensions of occluso-gingival height 1.5mm, mesio-distal width of 3mm. The depth of the cavity was 2mm and was calibrated by measuring with a pre marked periodontal probe. The teeth were randomly divided into four groups according to the cure mode and filling teqnique. Each group consist of 5 teeth (10 cavities); Group I; each cavity filled with 2mm (micro-hybrid resin composite) and cured with Quartz Tungsten Halogen light unit (QTH), Group II; the same as Group I but cured with Light Emitting Diod (LED cure unit), Group III; each cavity filled with glass ionomer lining of 0.5mm and 1.5mm (micro-hybrid resin composite), and cured with Quartz Tungsten Halogen light unit (QTH), & Group IV; each cavity filled with glass ionomer lining of 0.5mm and 1.5mm (micro-hybrid resin composite) but cured with Light Emitting Diod (LED cure unit). Temperature was measured before light curing of the composite resin & immediately after it. Then the Temperature was measured by a type K thermocouple.The results revealed that there were significant differences between the groups at p<0.01 with in favor of the group filled with composite resin & cured with LED with glass ionomer lining.The use of sandwich restorations with LED curing unit produced lesser temperature degrees toward the pulp space.
41
Basha, U. Mahaboob, D. Mohana Krishnudu, P. Hussain, K. Manohar Reddy, N. Karthikeyan e M. Ashok Kumar. "Synthesis and Characterization and Properties Comparison of Epoxy Filled Filler Millet (Ragi) Filler and Treated Sacharun offinarum (Sugar Cane) Fiber Reinforced Composites". International Letters of Chemistry, Physics and Astronomy 51 (maggio 2015): 41–46. http://dx.doi.org/10.18052/www.scipress.com/ilcpa.51.41.
Testo completoAbstract (sommario):
In the current work epoxy resin is chosen as matrix, treated Sacharum offinarum ( SugarCane) fiber, filler millet(Ragi) filler is chosen as reinforcement. Room temperature cured Epoxy System filled with Sacharum offinarum fiber and filler millet (Ragi) filler is synthesised by mechanical shear mixer, then kept in a Ultra sonic Solicitor for better dispersion of filler millet (Ragi) filler in the matrix. Different weights of modified filler millet(Ragi) filler (1,2,3,4,5 gm wt) has been incorporated into the Epoxy matrix in order to study the variation of Mechanical and Thermal properties.Mechanical properties like Flexural strength, Tensile strength and impact strength of the micro hybrid composite are studied by UTM (Universal Testing Machine). Thermal properties of micro hybrid composites are studied using Thermo Gravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC).
42
Basha, U. Mahaboob, D. Mohana Krishnudu, P. Hussain, K. Manohar Reddy, N. Karthikeyan e M. Ashok Kumar. "Synthesis and Characterization and Properties Comparison of Epoxy Filled Filler Millet (Ragi) Filler and Treated <i>Sacharun offinarum</i> (Sugar Cane) Fiber Reinforced Composites". International Letters of Chemistry, Physics and Astronomy 51 (15 maggio 2015): 41–46. http://dx.doi.org/10.56431/p-t46nj3.
Testo completoAbstract (sommario):
In the current work epoxy resin is chosen as matrix, treated Sacharum offinarum ( SugarCane) fiber, filler millet(Ragi) filler is chosen as reinforcement. Room temperature cured Epoxy System filled with Sacharum offinarum fiber and filler millet (Ragi) filler is synthesised by mechanical shear mixer, then kept in a Ultra sonic Solicitor for better dispersion of filler millet (Ragi) filler in the matrix. Different weights of modified filler millet(Ragi) filler (1,2,3,4,5 gm wt) has been incorporated into the Epoxy matrix in order to study the variation of Mechanical and Thermal properties.Mechanical properties like Flexural strength, Tensile strength and impact strength of the micro hybrid composite are studied by UTM (Universal Testing Machine). Thermal properties of micro hybrid composites are studied using Thermo Gravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC).
43
Paturel, Angeline, e Hom Nath Dhakal. "Influence of Water Absorption on the Low Velocity Falling Weight Impact Damage Behaviour of Flax/Glass Reinforced Vinyl Ester Hybrid Composites". Molecules 25, n. 2 (9 gennaio 2020): 278. http://dx.doi.org/10.3390/molecules25020278.
Testo completoAbstract (sommario):
Due to rigorous new environmental legislations, automotive, marine, aerospace, and construction sectors have redirected their focus into using more recyclable, sustainable, and environmentally friendly lightweight materials driven by strengthening resource efficiency drive. In this study, the influence of moisture absorption on flax and flax/glass hybrid laminates is presented with the aim to investigating their low velocity impact behaviour. Three different types of composite laminates namely, flax fibre reinforced vinyl ester, flax fibre hybridised glass fibre and glass fibre reinforced vinyl ester composites were fabricated using resin infusion technique. The moisture immersion tests were undertaken by immersing the different specimens in sea water bath at room temperature and 70 °C at different time durations. The low velocity falling weight impact testing was performed at 25 Joules of incident energy level and impact damage behaviour was evaluated at both ageing conditions using scanning electron microscopy (SEM) and X-ray microcomputed tomography (micro CT). The percentage of moisture uptake was decreased for flax vinyl ester specimens with glass fibre hybridisation. The maximum percentage of weight gain for flax fibre, flax/glass hybrid and glass fibre reinforced composites immersed at room temperature for 696 h is recorded at 3.97%, 1.93%, and 0.431%, respectively. The hybrid composite exhibited higher load and energy when compared flax/vinyl ester composite without hybridisation, indicating the hybrid system as a valid strategy towards achieving improved structural performance of natural fibre composites. The moisture absorption behaviour of these composites at room was observed to follow Fickian behaviour.
44
Ahmed, Muhammad Adeel, Rizwan Jouhar e Fahim Vohra. "Effect of Different pH Beverages on the Color Stability of Smart Monochromatic Composite". Applied Sciences 12, n. 9 (20 aprile 2022): 4163. http://dx.doi.org/10.3390/app12094163.
Testo completoAbstract (sommario):
Omnichroma is a smart monochromatic material and is believed to attain the shade of the surrounding tooth structure in which it is placed. However, the color stability of this material is unknown. Therefore, this study was conducted to evaluate the effect of different pH beverages on the color stability of the Omnichroma composite and its comparison with micro-hybrid composite resin. Sixty extracted human maxillary premolars of different shades, viz. A2, A3, B2 and B3, were selected in equal numbers. A Class V cavity was prepared on the buccal and palatal sides of each tooth. After the cavity preparation, etching of the cavity was performed with 35% phosphoric acid followed by bonding. The prepared cavities were then filled with Omnichroma composite resin on the buccal side and Filtek Z250 composite on the palatal side. The baseline color measurements of all tooth samples were performed by a spectrophotometer. The teeth were then divided into three groups, the Pepsi group, coffee group and milk tea group. Five teeth from each shade, viz. A2, A3, B2 and B3, were immersed in 10-mL of Pepsi, coffee, and milk tea for 14 days. After the completion of the 14 days, the teeth were rinsed and kept in distilled water for 24 h. Finally, a spectrophotometer was used to calculate the color alteration value ΔE. Mean difference in ΔE values of the samples before and after immersion in different beverages was calculated and analysed by SPSS 25. One-way ANOVA test was applied to compare groups. Further stratification was performed using the Post-Hoc Tukeys test. Samples immersed in milk tea showed a statistically significant difference (p < 0.05) in A2, A3, and B2 shades of the OM-milk tea group in comparison with the FT-milk tea group. In summary, the immersion of teeth in beverages with a different pH and colorants showed an apparent alteration in the color of both the smart monochromatic and micro-hybrid composites. Hence, the type of resin composite material should be selected wisely depending on the patient’s drinking and social habits.
45
Salih, Sihama Issa. "Characterization of thermo-physical and hardness properties of unsaturated polyester resin hybrid nano composites Sihama Issa Salih1, Waleed Bdaiwi Salih2, Husam Sakin Hamad2". Iraqi Journal of Physics (IJP) 16, n. 37 (11 settembre 2018): 136–48. http://dx.doi.org/10.30723/ijp.v16i37.85.
Testo completoAbstract (sommario):
In this work, two groups of nanocomposite material, was prepared from unsaturated polyester resin (UPE), they were prepared by hand lay-up method. The first group was consisting of (UPE) reinforced with individually (ZrO2) nanoparticles with particle size (47.23nm). The second group consists of (UPE) reinforced with hybrid nanoparticles consisting of zirconium oxide and yttrium oxide (70% ZrO2 + 30% Y2O3) with particles size (83.98nm). This study includes the effect of selected volume fraction (0.5%, 1%, 1.5%, 2%, 2.5%, 3%) for both reinforcement nano materials. Experimental investigation was carried out by analyzing the thermo-physical properties like thermal conductivity, thermal diffusivity and specific heat for the polymeric composites samples, as well as the hardness test. The results showed that the values of (hardness, specific heat) increased as the nanoparticle content in composite samples increased for both groups’ nanocomposites, whereas the values of thermal conductivity and thermal diffusion decrease for both groups composites. And it was found that the properties of composite materials reinforced by hybrid nanoparticles have higher properties as compared with their counterparts of other nanocomposite reinforced by zirconia nanoparticle. The morphology of the fracture surface was showed homogeneous micro structure formation for both groups composites, indicating a good compatibility between the matrix material and the reinforcement nanoparticles.
46
Terkla, L. G., A. C. Brown, A. P. Hainisch e J. C. Mitchem. "Testing Sealing Properties of Restorative Materials Against Moist Dentin". Journal of Dental Research 66, n. 12 (dicembre 1987): 1758–64. http://dx.doi.org/10.1177/00220345870660121201.
Testo completoAbstract (sommario):
The objectives of this investigation were (1) to develop a sensitive laboratory system that simulates the physiological and clinical conditions of a prepared human tooth in order to facilitate the determination of the bonding and sealing efficacies of restorative dental materials and (2) to conduct experiments with two dentin bonding agents, two posterior composite resin restorative materials (hybrid and micro filled), and a glass-ionomer type II filling material. The system functioned well and provided data to indicate that, after margination, the two posterior composite resin restorative materials performed equally and both performed better than the glass-ionomer filling material; none of the materials provided a perfect seal immediately after insertion, although some restorations demonstrated perfect seals from 16 hours to 28 days after placement; the seal of the glass-ionomer material improved after 28 days of storage in buffer solution; each successive step in the respective composite resin procedures improved the seal except in one case for the micro filled resin.
47
Xu, Xinwu, Feiyu Tian e Xiaoke Li. "Regenerated waste tire powders as fillers for wood fiber composites". BioResources 15, n. 2 (16 marzo 2020): 3029–40. http://dx.doi.org/10.15376/biores.15.2.3029-3040.
Testo completoAbstract (sommario):
Waste rubber retains good elasticity and can be regenerated for use in special applications. In this research, wood fiber composites were made with waste tire powders (WTPs) as functional fillers. The physical-mechanical properties of the wood-rubber composite (WRC) panels, i.e., inner bond (IB) strength, static bending modulus (MOE), strength (MOR), and thickness swelling (TS) were assessed. The surface micro-morphology of the WRC panels was quantitatively analyzed and was graphically simulated with Matlab software. The results showed that WTPs decreased the mechanical strength and modulus of the hybrid composites, which was caused by the weak fiber/WTP interfacial adhesion. The addition of WTPs roughened the surface of composite panels. However, WRC panels showed improved hygroscopic stability and flexibility compared to pure wood fiber composites. Sanding can flatten the rougher WRC panel surface; however, it brings tiny pits to the surface that are caused by loss of rubber powders. Surface overlaying with resin impregnated paper was found to be effective to cover the tiny pits. This study showed that it is feasible to make value added rubber filled wood fiber composites with satisfactory performance.
48
Karthick, L., R. Rathinam, Sd Abdul Kalam, Ganesh Babu Loganathan, R. S. Sabeenian, S. K. Joshi, L. Ramesh, H. Mohammed Ali e Wubishet Degife Mammo. "Influence of Nano-/Microfiller Addition on Mechanical and Morphological Performance of Kenaf/Glass Fibre-Reinforced Hybrid Composites". Journal of Nanomaterials 2022 (5 settembre 2022): 1–10. http://dx.doi.org/10.1155/2022/9778224.
Testo completoAbstract (sommario):
Natural-based composite’s progress as carriers has revealed many benefits in biomedicine, notably in the construction field, synthetic biology, and genetic engineering. Compared to analogous composites without nanoparticles, incorporating nanoparticles into polymeric materials improved architectural performance, physiological connections, and ecological features. The major goal of the current investigation is to determine the impact of nano-/micro-TiO2 on the mechanical characteristics of kenaf/glass/epoxy hybrids. The samples have been created using a hand layup method and a variety of filler loading and stacking sequences. The addition of nano-/microfiller significantly improved the mechanical performance of the epoxy/hybrid composite material. It was discovered that nanofiller-added composite materials fared better when composites were compared to and without microfilter-added composites. SEM was used to investigate the microstructure of the interfaces to ensure a good understanding of interfacial adherence between the reinforcement and their matrix. Compared to pure epoxy resin, the 15 wt% of microfiller additions of glass-kenaf-kenaf-glass type composites exhibit a 39.48% improvement in tensile and a 42.88% improvement in flexural. Similarly, 5 wt% nanofiller addition reveals a 44.214% improvement in tensile and a 50.50% improvement in flexural.
49
Adel Harfosh, Ahmed, Mohamed M. abdelkahlek e Tarek Mohamed El Sherifa. "Nano-hybrid versus micro-hybrid composite as reinforced resin for ribbon bar attachment." Mansoura Journal of Dentistry 7, n. 27 (1 luglio 2020): 44–49. http://dx.doi.org/10.21608/mjd.2020.198733.
Testo completo
50
SAKODA, Kentaro, Amane KITAYAMA, Akio OHTANI e Asami NAKAI. "Mechanical Behavior of Resin Hybrid Braided Composites Considering Micro Fractures". Journal of the Society of Materials Science, Japan 61, n. 7 (2012): 654–61. http://dx.doi.org/10.2472/jsms.61.654.
Testo completo