scholarly journals Studying the Impact Strength of Layered Denture Base Resin

2020 ◽  
Vol 18 (44) ◽  
pp. 25-32
Author(s):  
Samar Abbas Hannon ◽  
Wafaa A. Hussain ◽  
Selma M. Hussain
Keyword(s):  
Carbon Fiber ◽  
Impact Strength ◽  
Carbon Fibers ◽  
High Impact ◽  
Control Group ◽  
Denture Base ◽  
Base Resin ◽  
High Impact Strength ◽  
The Impact ◽  
Denture Base Resin

This paper displays the effect of uncoated and coated chopped carbon fibers with alumina Al2O3 or Tri calcium phosphate (TCP) on the impact strength of acrylic poly methyl methacrylate (PMMA) denture base resin. To improve bonding between carbon fibers and coating materials powders, the surface of carbon fibers has been treated with Para amino benzoic acid (C9H10N2O3) and poly vinyl alcohol (PVA) was also used. The morphology of the coating layers has been examined by field emission scanning electron microscope (FE-SEM). From the results, PMMA reinforced with uncoated chopped carbon fiber has high impact strength value but still have bad aesthetic.  Samples prepared by coated carbon fiber with Al2O3 or TCP have high impact strength values when compared to control group with good aesthetic. Impact strength was increased in samples when PVA increased and fibers amount decreased.

scholarly journals Effect of Incorporation of Different Concentrations of Silver Nanoparticles as an Antimicrobial Agent on the Flexural and Impact Strength of Heat-Cured Denture Base Resin

2021 ◽  
Author(s):  
Piyali Sarkar ◽  
Sandeep Garg ◽  
Nidhi Mangtani Kalra
Keyword(s):  
Silver Nanoparticles ◽  
Impact Strength ◽  
Flexural Strength ◽  
Antimicrobial Agent ◽  
Bending Test ◽  
Denture Base ◽  
Significant Difference ◽  
Base Resin ◽  
The Impact ◽  
Denture Base Resin

Abstract Aim This article evaluates the effect of incorporating different concentrations of silver nanoparticles as an antimicrobial agent on the flexural and impact strength of heat-cured denture base resin. Material and Methods A total of 80 specimens of polymethyl methacrylate resin were fabricated (40 for flexural strength and 40 for impact strength). Specimens were fabricated using stainless steel die of dimension 65 mm × 10 mm × 2.5 mm as per the American Dental Association specification no. 12, and 50 mm × 6 mm × 4 mm as per ISO 1567:1999 for flexural strength and impact strength, respectively, and were divided into four groups (A, B, C, and D) based on the concentrations of silver nanoparticles (0%, 2.5%, 5%, and 10%). The specimens were subjected to three-point bending test and Izod impact tester for testing flexural and impact strength, respectively. Data obtained was compiled and analyzed using one-way analysis of variance and post hoc tests. Results Results showed that for both the properties, maximum strength was observed in group A (control) followed by groups B and C, and minimum was observed in group D. A statistically significant difference in flexural strength was found among all the groups, whereas no statistically significant difference in impact strength was found among any of the groups. Conclusion Within the limitations of this in vitro study, it was concluded that though incorporation of silver nanoparticles exhibited no effect on the impact strength of heat cure denture base resin, it decreased the flexural strength, so it should be used cautiously.

scholarly journals The Effect of Coca Cola Drink on the Impact Strength and Surface Roughness of Acrylic Denture Base

2018 ◽  
Vol 2 (2) ◽  
pp. 120-131
Author(s):  
Fahd Ikram
Keyword(s):  
Surface Roughness ◽  
Impact Strength ◽  
Plastic Material ◽  
Base Material ◽  
Control Group ◽  
Denture Base ◽  
Heat Cure ◽  
Base Resin ◽  
Group A ◽  
The Impact

Despite the development of many denture base material like chrome-cobalt, fluid and plastic material but the heat cure polymethylmethacrylate considered as the most widely used denture base material. The aims of this study to evaluate and compare the impact strength and surface roughness of heat cured denture base resin after immersing incoca-cola drink for two and four weeks. Methods: A total number of 40 samples were prepared, 30 samples for impact strength test and 10 samples for surface roughness test. The samples were divided into three group; A (control), B (2 weeks immersed in coca cola drink), and C (4 weeks immersed in coca cola drink). Result: Data analyzed by using SPSS software with ANOVA test indicated a non significant differences between the different tested groups, however the samples that were immersed in coca cola drink for 4 weeks revealed non dramatic increase in surface roughness, while the samples that were immersed for 2 weeks showed a non dramatic decrease in the impact strength. Conclusions: The coca cola drink non significantly caused dropping in the tested properties in comparison to the control group.

Hybrid effects of carbon fiber and nanoclay as fillers on the performances of recycled wood-plastic composites

BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 7671-7686
Author(s):  
Young-Rok Seo ◽  
Sang-U Bae ◽  
Birm-June Kim ◽  
Min Lee ◽  
Qinglin Wu
Keyword(s):  
Carbon Fiber ◽  
Impact Strength ◽  
Carbon Fibers ◽  
Synergistic Effects ◽  
Flexural Modulus ◽  
Tensile Modulus ◽  
Raw Material ◽  
Scanning Electron Micrographs ◽  
Plastic Composite ◽  
The Impact

Waste wood-plastic composite (WPC) was used in this work as a raw material to produce recycled WPCs reinforced with carbon fiber and nanoclay. To evaluate the synergistic effects of carbon fiber and nanoclay, various performances (i.e., microstrucural, mechanical, thermal, water absorption, and electrical properties) were investigated. Scanning electron micrographs and X-ray diffraction analysis of the fillers (carbon fiber and nanoclay) present in the recycled WPCs showed that the nanoclays were properly intercalated when filled with carbon fibers. According to mechanical property analysis, hybrid incorporation of carbon fibers and nanoclays improved impact strength, tensile strength, and flexural strength. However, further incorporation of nanoclays reduced the impact strength and did not improve the tensile modulus or the flexural modulus. The carbon fibers present in the recycled WPCs improved the electrical conductivity of the composites, despite the various fillers that interfered with their electrical conduction. In addition, carbon fibers and nanoclays were mixed into the recycled WPCs to improve the thermal stability of the composites. Finally, the presence of nanoclays in recycled WPCs led to increased water uptake of the composites.

scholarly journals Effect of Food Simulating Agents on the Hardness and Bond Strength of a Silicone Soft Liner to a Denture Base Acrylic Resin

2015 ◽  
Vol 9 (1) ◽  
pp. 402-408 ◽  
Author(s):  
A.A.R. Khaledi ◽  
M. Bahrani ◽  
S. Shirzadi
Keyword(s):  
Citric Acid ◽  
Bond Strength ◽  
Acrylic Resin ◽  
Tensile Bond Strength ◽  
Control Group ◽  
Denture Base ◽  
Bonding Failure ◽  
Base Resin ◽  
Soft Liner ◽  
Denture Base Resin

Statement of the Problem: Bonding failure between acrylic resin and soft liner material and also gradual loss of soft liner resiliency over time are two impending challenges frequently recognized with a denture base embraced with a resilient liner. Since patients drink various beverages, it is crucial to assess the influences of these beverages on physical characteristics of soft liners. Purpose: This in vitro study envisioned to assess the influence of food simulating agents (FSA) on the hardness of a silicone soft liner by employing a Shore A durometer test and also evaluate its bond strength to a denture base resin by using tensile bond strength test. Materials and Methods: To test the hardness of samples, 50 rectangular samples (40 mm × 10 mm × 3 mm) were prepared from a heat-polymerized polymethyl methacrylate (Meliodent). Mollosil, a commercially available silicone resilient liner, was provided and applied on the specimens following the manufacturer’s directions. In order to test tensile bond strength, 100 cylindrical specimens (30 mm × 10 mm) were fabricated. The liners were added between specimens with the thicknesses of 3 mm. The specimens were divided into 5 groups (n=10) and immersed in distilled water, heptane, citric acid, and 50% ethanol. For each test, we used 10 specimens as a baseline measurement; control group. All specimens were kept in dispersed containers at 37ºC for 12 days and all solutions were changed every day. The hardness was verified using a Shore A durometer and the tensile bond strength was examined by an Instron testing machine at a cross-head speed of 5 mm/min. The records were analyzed employing one-way ANOVA, Tukey’s HSD, and LSD tests. Results: The mean tensile bond strength ± standard deviation (SD) for Mollosil was as follows for each group: 3.1 ± 0.4 (water), 1.8 ± 0.4 (citric acid), 3.0 ± 0.4 (heptane), 1.2 ± 0.3 (50% ethanol), and 3.8 ± 0.4 (control). The hardness values for each group were: 28.7 ± 2.11 (water), 33.2 ± 2.82 (citric acid), 39.2 ± 4.8 (heptane), 32.3 ± 3.56 (50% ethanol) and 22.2 ± 2.08 (control). Mean values for hardness indicated that all of the food simulating agents significantly increased hardness of the Mollosil soft liner compared to the control group (p<0.05). The results of tensile bond strength depicted that water and FSA decreased the bond strength of the soft liner -denture base resin compared to the control group and it was statistically significant (p<0.05). Conclusion: The food simulating agents could influence the mechanical properties of silicone soft liners; hence, clinicians should inform their patients concerning their possible adverse effects and complications.

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