The Experts below are selected from a list of 315 Experts worldwide ranked by ideXlab platform
Sang Wan Shin - One of the best experts on this subject based on the ideXlab platform.
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Effect of aging on Tear Strength and cytotoxicity of soft denture lining materials; in vitro.
The Journal of Advanced Prosthodontics, 2014Co-Authors: Jordi Izzard Andaya Landayan, Adrian Carlos Francisco Manaloto, Sang Wan ShinAbstract:PURPOSE: The aim of this in vitro study was to evaluate the effect of aging on the Tear Strength and cytotoxicity of four soft denture lining materials. MATERIALS AND METHODS: Four commonly used soft denture lining materials, (Coe-Comfort™ GC America Inc., Alsip, IL, USA; Coe-Soft™ GC America Inc., Alsip, IL, USA; Visco-gel Dentsply Caulk Milford, DE, USA; and Sofreliner Tough M Tokuyama Dental Corporation Tokyo, Japan) were selected. Sixty trouser-leg designed specimens per lining material were fabricated using a stainless steel mold for Tear Strength testing. The specimens were divided into non-thermocycling and 1000-, and 3000- thermocycling groups. For the cytotoxicity test, twenty-four disk shaped specimens per material were fabricated using a stainless steel mold. The specimens were soaked in normal saline solution for 24 h, 48 h and 72 h. Cytotoxicity was measured by XTT assay in L929 mouse fibroblasts. Data were analyzed by two way analysis of variance and Dunnett's test (P
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effect of aging on Tear Strength and cytotoxicity of soft denture lining materials in vitro
The Journal of Advanced Prosthodontics, 2014Co-Authors: Jordi Izzard Andaya Landayan, Adrian Carlos Francisco Manaloto, Sang Wan ShinAbstract:PURPOSE: The aim of this in vitro study was to evaluate the effect of aging on the Tear Strength and cytotoxicity of four soft denture lining materials. MATERIALS AND METHODS: Four commonly used soft denture lining materials, (Coe-Comfort™ GC America Inc., Alsip, IL, USA; Coe-Soft™ GC America Inc., Alsip, IL, USA; Visco-gel Dentsply Caulk Milford, DE, USA; and Sofreliner Tough M Tokuyama Dental Corporation Tokyo, Japan) were selected. Sixty trouser-leg designed specimens per lining material were fabricated using a stainless steel mold for Tear Strength testing. The specimens were divided into non-thermocycling and 1000-, and 3000- thermocycling groups. For the cytotoxicity test, twenty-four disk shaped specimens per material were fabricated using a stainless steel mold. The specimens were soaked in normal saline solution for 24 h, 48 h and 72 h. Cytotoxicity was measured by XTT assay in L929 mouse fibroblasts. Data were analyzed by two way analysis of variance and Dunnett's test (P<.05). RESULTS: Before thermocycling, Sofreliner Tough M (10.36 ± 1.00 N) had the highest Tear Strength value while Coe-Comfort™ (0.46 ± 0.10 N) had the lowest. After 3000 cycles, Sofreliner Tough M (9.65 ± 1.66 N) presented the highest value and Coe-Comfort™ (0.42 ± 0.08 N) the lowest. Sofreliner Tough M, in all incubation periods was the least toxic with significant differences compared to all other materials (P<.05). Coe-Comfort™, Coe-Soft™, and Sofreliner Tough M did not show any significant differences within their material group for all incubation periods. CONCLUSION: This in vitro study revealed that aging can affect both the Tear Strength and cytotoxicity of soft denture materials depending on the composition.
Hanafi Ismail - One of the best experts on this subject based on the ideXlab platform.
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Effect of filler loading on tensile and Tear properties of SMR L/ENR 25 and SMR L/SBR blends cured via a semi-efficient vulcanization system
Polymer Testing, 2020Co-Authors: Hanafi IsmailAbstract:Abstract The effects of filler loading on the tensile and Tear properties of SMR L/ENR 25 and SMR L/SBR blends using a semi-efficient vulcanization system was studied. Carbon black (N330), silica (Vulcasil C) and calcium carbonate were used as the fillers and the loading range was from 0 to 40 phr. Tensile Strength, M300 (tensile stress at 300% elongation) and Tear Strength were determined using a Monsanto Tensometer (Model T10) operating at 50 cm/min. Results show that for the carbon black and silica-filled blends, elongation at break decreases, but tensile Strength, M300 and Tear Strength increase with filler loading. The reverse behavior is obtained for the calcium carbonate-filled blends. This observation is attributed to the better rubber–filler interphase interaction of carbon black and silica compared to the non-reinforcing nature of calcium carbonate, the dilution effect of which becomes more significant as the filler loading is increased. For a fixed filler loading, SMR L/ENR 25 blend consistently exhibits higher tensile Strength, M300 and Tear Strength but lower elongation at break compared to SMR L/SBR blend. This finding is associated with the mutual rubber reinforcement between the two strain-induced crystallizable rubbers (i.e. SMR L and ENR 25), coupled with good rubber–filler interaction, particularly between silica and ENR 25 in the former blend.
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oil palm wood flour reinforced epoxidized natural rubber composites the effect of filler content and size
European Polymer Journal, 1997Co-Authors: Hanafi Ismail, R. M. Jaffri, H. D. Rozman, Z Mohd A IshakAbstract:Abstract The effect of filler content and size on curing characteristics and mechanical properties of oil palm wood flour (OPWF) reinforced epoxidized natural rubber (ENR) composites has been studied. The cure (t90) and scorch times of all filler size decrease with increasing OPWF content. At any filler content, larger OPWF particle size show shorter t90 and scorch time. The torque values increase with an increase in fibre content and OPWF with smallest particle size shows the highest torque. Increasing OPWF content in ENR compound resulted in reduction of tensile Strength and elongation at break but increased tensile modulus, Tear Strength and hardness. Again, the composites filled with smaller OPWF size showed higher tensile Strength, tensile modulus and Tear Strength.
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A Comparative Study of the Effect of Thermo-Oxidative Aging on the Physical Properties of Rice Husk Ash and Commercial Fillers in Epoxidized Natural Rubber Compounds
Journal of Elastomers and Plastics, 1997Co-Authors: Hanafi Ismail, A. A. Azhar, Umaru Semo Ishiaku, Z. A. Mohd IshakAbstract:The effect of thermo-oxidative aging on physical properties viz. modulus, tensile Strength, elongation at break, Tear Strength and hardness of rice husk ash (RHA) and commercial fillers in ENR compounds have been studied. While the modulus and hardness increased with aging, other properties, i.e., tensile Strength, elongation at break and Tear Strength decreased. The poor retention in properties indicates that thermo-oxidative aging process has resulted in permanent damage to the vulcanizates. The hardening and brittleness of the aged vulcanizates provides clear evidence for the aging process. The comparable retention values of both white rice husk ash (WRHA), black rice husk ash (BRHA), carbon black and silica filled vulcanizates indicates that the thermo-oxidative aging behaviour is determined predominantly by the ENR matrix. Scanning electron microscopy on fracture surfaces after aging shows the filler particles were poorly wetted by the rubber matrix. This explains the dramatic reduction in tensile Strength, elongation at break and Tear Strength after aging.
Marcelo Coelho Goiato - One of the best experts on this subject based on the ideXlab platform.
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Influence of Different Pigmentations and Accelerated Aging on the Hardness and Tear Strength of the A-2186 and MDX4-4210 Silicones.
International journal of dentistry, 2020Co-Authors: Estefânia Marrega Malavazi, Daniela Micheline Dos Santos, Clóvis Lamartine De Moraes Melo Neto, Fernanda Pereira De Caxias, Emily Vivianne Freitas Da Silva, Lisiane Cristina Bannwart, Aldiéris Alves Pesqueira, André Luiz De Melo Moreno, André Pinheiro De Magalhães Bertoz, Marcelo Coelho GoiatoAbstract:To evaluate the influence of different pigmentations and accelerated aging on the hardness and Tear Strength of the A-2186 and MDX4-4210 silicones. The samples A-2186 and MDX4-4210 were manufactured without and with pigmentations (black, bronze, and pink). For the Shore A hardness test, 80 samples of each silicone were fabricated, and for the Tear Strength test, 320 samples of each silicone were fabricated. Eight groups were created for each test (n = 10). These tests were performed before and after 252, 504, and 1008 hours of aging. Three-way repeated-measures analysis of variance and the Tukey test were performed (α = 0.05). The A-2186 silicone showed higher hardness and Tear Strength when compared with the MDX4-4210 silicone (p < 0.05), except in the hardness of the A-2186 and MDX4-4210 groups without pigmentation after 1008 hours (p > 0.05). All hardness values were between 25 and 35 units, regardless of the silicone type, period, and pigmentation (or no pigmentation). In most situations, the hardness of silicones used increased after 252 hours (p < 0.05). The nonpigmented MDX4-4210 group and all A-2186 groups showed an increase in Tear Strength after 252 hours (p < 0.05). For the nonpigmented MDX4-4210 group, from 252 to 1008 hours, there was no change in Tear Strength (p > 0.05). All pigmented MDX4-4210 groups showed no change in Tear Strength from 0 (initial) to 1008 hours of aging (p > 0.05). In all A-2186 groups, from 252 to 504 hours, there was a reduction in Tear Strength (p < 0.05), and from 504 to 1008 hours, there was an increase in Tear Strength (p < 0.05), except in the bronze A-2186 group (p > 0.05). In most situations, the A-2186 silicone showed significantly higher values of hardness and Tear Strength than the MDX4-4210 silicone. All hardness values were considered clinically acceptable. Accelerated aging could increase, decrease, or not significantly change the hardness and Tear Strength of the silicones used. The results of hardness and Tear Strength suggest that MDX4-4210 was more influenced by the presence of pigmentation after aging. Copyright © 2020 Estefânia Marrega Malavazi et al.
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influence of different pigmentations and accelerated aging on the hardness and Tear Strength of the a 2186 and mdx4 4210 silicones
International Journal of Dentistry, 2020Co-Authors: Estefânia Marrega Malavazi, Clóvis Lamartine De Moraes Melo Neto, Lisiane Cristina Bannwart, Aldiéris Alves Pesqueira, André Pinheiro De Magalhães Bertoz, Daniela Micheline Dos Santos, Fernanda Pereira De Caxias, Emily Vivianne Freitas Da Silva, A Moreno, Marcelo Coelho GoiatoAbstract:Objective To evaluate the influence of different pigmentations and accelerated aging on the hardness and Tear Strength of the A-2186 and MDX4-4210 silicones. Materials and methods The samples A-2186 and MDX4-4210 were manufactured without and with pigmentations (black, bronze, and pink). For the Shore A hardness test, 80 samples of each silicone were fabricated, and for the Tear Strength test, 320 samples of each silicone were fabricated. Eight groups were created for each test (n = 10). These tests were performed before and after 252, 504, and 1008 hours of aging. Three-way repeated-measures analysis of variance and the Tukey test were performed (α = 0.05). Results The A-2186 silicone showed higher hardness and Tear Strength when compared with the MDX4-4210 silicone (p 0.05). All hardness values were between 25 and 35 units, regardless of the silicone type, period, and pigmentation (or no pigmentation). In most situations, the hardness of silicones used increased after 252 hours (p 0.05). All pigmented MDX4-4210 groups showed no change in Tear Strength from 0 (initial) to 1008 hours of aging (p > 0.05). In all A-2186 groups, from 252 to 504 hours, there was a reduction in Tear Strength (p 0.05). Conclusion In most situations, the A-2186 silicone showed significantly higher values of hardness and Tear Strength than the MDX4-4210 silicone. All hardness values were considered clinically acceptable. Accelerated aging could increase, decrease, or not significantly change the hardness and Tear Strength of the silicones used. The results of hardness and Tear Strength suggest that MDX4-4210 was more influenced by the presence of pigmentation after aging.
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Tear Strength analysis of mdx4 4210 and a 2186 silicones with different intrinsic pigments incorporated by mechanical and industrial methods
International Journal of Dentistry, 2019Co-Authors: Marcelo Coelho Goiato, André Pinheiro De Magalhães Bertoz, Daniela Micheline Dos Santos, Emily Vivianne Freitas Da Silva, Adhara Smith Nobrega, Mariana Vilela Sonego, Clóvis Lamartine De Moraes Melo NetoAbstract:Objective. The aim of this study was to evaluate the Tear Strength of MDX4-4210 and A-2186 silicones with different intrinsic pigments incorporated by mechanical and industrial methods, comparing nonaged and aged groups. Materials and Methods. Twenty-four groups were created according to the American Society for Testing and Materials D-624/type C, half nonaged and half aged (n = 10): bronze mechanical MDX4-4210, bronze industrial MDX4-4210, black mechanical MDX4-4210, black industrial MDX4-4210, pink mechanical MDX4-4210, pink industrial MDX4-4210, bronze mechanical A-2186, bronze industrial A-2186, black mechanical A-2186, black industrial A-2186, pink mechanical A-2186, and pink industrial A-2186. All specimens were submitted to Tear Strength analysis. Data were submitted to the ANOVA and Tukey test ( ). Results. An increase in the Tear Strength values was observed only for the bronze and black MDX4-4210, comparing nonaged and aged silicones ( ), regardless of the manufacturing method. There was a difference in all comparisons between MDX4-4210 and A-2186 silicones with the same pigment type ( ), regardless of the manufacturing method. In all cases, there was no difference in the manufacturing method comparing the MDX4-4210 or A-2186 groups with the same pigment. Conclusion. Accelerated aging did not influence the Tear Strength in all aged A-2186 silicones and in aged pink industrial and mechanical MDX4-4210 silicones. The other MDX4-4210 groups had an increase in the results after aging. In all cases compared, the A-2186 groups had higher Tear Strength values than the MDX4-4210 groups. Mechanical and industrial methods can be used for silicone preparation, without changing the Tear Strength.
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influence of adding nanoparticles on the hardness Tear Strength and permanent deformation of facial silicone subjected to accelerated aging
Journal of Prosthetic Dentistry, 2016Co-Authors: Adhara Smith Nobrega, Daniela Micheline Dos Santos, Agda Marobo Andreotti, Amalia Moreno, Mario Alexandre Coelho Sinhoreti, Marcelo Coelho GoiatoAbstract:Abstract Statement of problem The efficiency of adding nanoparticles to silicone protection has proven to prevent color degradation. However, reports of other physical property changes in facial silicone are scarce. Purpose The purpose of this in vitro study was to evaluate the influence of adding nanoparticles on the hardness, Tear Strength, and permanent deformation of a facial silicone. Material and methods Specimens were made for each test, with 140 for the hardness test, 140 for the permanent deformation test, but 280 for the rupture test. This higher number was due to the fact that the first 140 specimens were ruptured and unusable after the initial reading. ZnO, BaSO 4 , and TiO 2 nanoparticles at concentrations of 1% and 2% of silicone were used, as well as specimens without nanoparticles that consisted of only oil paint and of only silicone. Outcomes were measured before and after 1008 hours of accelerated aging. Data were analyzed by nested analysis of variance (ANOVA) and Tukey honest significant differences test (α=.05). Results Results showed that the presence of nanoparticles influenced the properties of the assessed groups. The nanoparticles decreased hardness values. The highest values of Tear Strength were observed for the groups with addition of BaSO 4 . The 1% ZnO group without oil paint showed the lowest values of permanent deformation. Conclusions Based on the findings of this in vitro study, the use of ZnO nanoparticles is recommended, since they did not negatively affect the properties of the materials evaluated.
Jordi Izzard Andaya Landayan - One of the best experts on this subject based on the ideXlab platform.
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Effect of aging on Tear Strength and cytotoxicity of soft denture lining materials; in vitro.
The Journal of Advanced Prosthodontics, 2014Co-Authors: Jordi Izzard Andaya Landayan, Adrian Carlos Francisco Manaloto, Sang Wan ShinAbstract:PURPOSE: The aim of this in vitro study was to evaluate the effect of aging on the Tear Strength and cytotoxicity of four soft denture lining materials. MATERIALS AND METHODS: Four commonly used soft denture lining materials, (Coe-Comfort™ GC America Inc., Alsip, IL, USA; Coe-Soft™ GC America Inc., Alsip, IL, USA; Visco-gel Dentsply Caulk Milford, DE, USA; and Sofreliner Tough M Tokuyama Dental Corporation Tokyo, Japan) were selected. Sixty trouser-leg designed specimens per lining material were fabricated using a stainless steel mold for Tear Strength testing. The specimens were divided into non-thermocycling and 1000-, and 3000- thermocycling groups. For the cytotoxicity test, twenty-four disk shaped specimens per material were fabricated using a stainless steel mold. The specimens were soaked in normal saline solution for 24 h, 48 h and 72 h. Cytotoxicity was measured by XTT assay in L929 mouse fibroblasts. Data were analyzed by two way analysis of variance and Dunnett's test (P
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effect of aging on Tear Strength and cytotoxicity of soft denture lining materials in vitro
The Journal of Advanced Prosthodontics, 2014Co-Authors: Jordi Izzard Andaya Landayan, Adrian Carlos Francisco Manaloto, Sang Wan ShinAbstract:PURPOSE: The aim of this in vitro study was to evaluate the effect of aging on the Tear Strength and cytotoxicity of four soft denture lining materials. MATERIALS AND METHODS: Four commonly used soft denture lining materials, (Coe-Comfort™ GC America Inc., Alsip, IL, USA; Coe-Soft™ GC America Inc., Alsip, IL, USA; Visco-gel Dentsply Caulk Milford, DE, USA; and Sofreliner Tough M Tokuyama Dental Corporation Tokyo, Japan) were selected. Sixty trouser-leg designed specimens per lining material were fabricated using a stainless steel mold for Tear Strength testing. The specimens were divided into non-thermocycling and 1000-, and 3000- thermocycling groups. For the cytotoxicity test, twenty-four disk shaped specimens per material were fabricated using a stainless steel mold. The specimens were soaked in normal saline solution for 24 h, 48 h and 72 h. Cytotoxicity was measured by XTT assay in L929 mouse fibroblasts. Data were analyzed by two way analysis of variance and Dunnett's test (P<.05). RESULTS: Before thermocycling, Sofreliner Tough M (10.36 ± 1.00 N) had the highest Tear Strength value while Coe-Comfort™ (0.46 ± 0.10 N) had the lowest. After 3000 cycles, Sofreliner Tough M (9.65 ± 1.66 N) presented the highest value and Coe-Comfort™ (0.42 ± 0.08 N) the lowest. Sofreliner Tough M, in all incubation periods was the least toxic with significant differences compared to all other materials (P<.05). Coe-Comfort™, Coe-Soft™, and Sofreliner Tough M did not show any significant differences within their material group for all incubation periods. CONCLUSION: This in vitro study revealed that aging can affect both the Tear Strength and cytotoxicity of soft denture materials depending on the composition.
Nancy R Sottos - One of the best experts on this subject based on the ideXlab platform.
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A self-healing poly(dimethyl siloxane) elastomer
Advanced Functional Materials, 2007Co-Authors: Michael W. Keller, Scott R White, Nancy R SottosAbstract:Self-healing functionality is imparted to a poly(dimethyl siloxane) (PDMS) elastomer. This new material is produced by the incorporation of a microencapsulated PDMS resin and a microencapsulated crosslinker into the PDMS matrix. A protocol based on the recovery of Tear Strength is introduced to assess the healing efficiency for these compliant polymers. While most PDMS elastomers possess some ability to re-mend through surface cohesion, the mechanism is generally insufficient to produce significant recovery of initial material Strength under ambient conditions. Self-healing PDMS specimens, however, routinely recover between 70-100% of the original Tear Strength. Moreover, the addition of microcapsules increases the Tear Strength of the PDMS. The effect of microcapsule concentration on healing efficiency is also investigated.
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Fatigue of self-healing elastomers
Proceedings of the First International Conference on Self Healing Materials, 2007Co-Authors: Michael W. Keller, Brett A. Beiermann, Scott R White, Nancy R SottosAbstract:Self-healing functionality has been imparted to a poly(dimethyl siloxane) (PDMS) elastomer. This material contains two microcapsule families, one containing a vinyl terminated PDMS resin and platinum catalyst compounds, the other containing a methylhydrosiloxane crosslinker. A new trouser Tear test protocol is developed to evaluate the healing performance of this material. This testing demonstrates that the self-healing elastomer is capable of routinely recovering over 70% of the initial Tear Strength. A full recovery of original Tear Strength is possible under certain conditions. Torsional fatigue testing is also performed to assess the capability of this self-healing material to retard and repair fatigue crack growth. The elastomer is able to recover a significant portion of its original torsional stiffness during cyclic loading
