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Article
Studying the effect of addition a composite of silanized Nano-Al2O3 and plasma treated polypropylene fibers on some physical and mechanical properties of heat cured PMMA denture base material

Authors: Omar R. Muklif --- Intisar J. Ismail انتصار جميل اسماعيل
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2015 Volume: 27 Issue: 3 Pages: 22-27
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: Polymethyl methacrylate (PMMA) is the most commonly used material in denture fabrication. Thematerial is far from ideal in fulfilling the mechanical requirements, like low impact and transverse strength, poorthermal conductivity. The purpose of this study was to evaluate the effect of addition a composite of surface treatedNano Aluminum oxide (Al2O3) filler and plasma treated polypropylene fiber (PP) on some properties of denture basematerial.Materials and methods: One hundred fifty prepared specimens were divided into 5 groups according to the tests,each group consisted of 30 specimens and these were subdivided into 3 groups (unreinforced heat cured acrylicresin as control group),reinforced acrylic resin with( 0.5%wt Nano Al2O3 and2.5%wt plasma treated PP fibers) groupand reinforced acrylic with(1%wt Nano Al2O3 and 2.5%wt plasma treated PP fibers group).The tests were impactstrength, transverse strength, indentation hardness(shore D), surface roughness thermal conductivity. The results werestatistically analyzed using ANOVA test.Results: A highly significant increase in impact strength, surface hardness, thermal conductivity with the addition of0.5%wt. (Al2O3) and 2.5%wt PP fiber to(PMMA),also there is a significant increase in surface roughness and nonsignificant increase in transverse strength. At the concentration of 1%wt nano (Al2O3)and 2.5%wt PP fiber there is ahighly significant increase in impact strength surface hardness and thermal conductivity. Non-significant differenceswere shown in transverse strength and significant increase in surface roughness.Conclusion: The addition of a composite of Al2O3 nanoparticles and PP fiber to PMMA improves the impact strength,surface hardness and thermal properties, surface roughness while non-significant difference in transverse strength


Article
In vitro Performance of Polymethyl–methacrylate with Ultra High Density Poly Ethylene Fiber and Nano Zirconium Oxide Particles Composite

Authors: Ahmed A. Mohammed --- Intisar J. Ismail انتصار جميل اسماعيل
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2018 Volume: 30 Issue: 1 Pages: 5-11
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: Poly (methyl methacrylate) has been widely utilized for fabrication of dentures for many years as it has good advantages but not achieved all demands of the mechanical properties such as low transverse strength, low impact strength, low surface hardness, high water solubility and high water sorption.Material and method: To provide bonding between ZrO2 nanoparticles and PMMA matrix, the ZrO2 Nano-fillers were surface-treated with a saline coupling agent. Plasma surface treatment of polyethylene (PE) fiber was done to change surface fiber by using DC- glow discharge system. For characterization of interring any functional groups, the (FTIR) spectrum were done .then the mechanical properties studied to choose the appropriate percentages to complete study.Results: The results revealed that highly significant difference between groups in transverse strength, the highest mean value (96.1700 N/mm2) found in 2.0% polyethylene fibers and 1.5% salinized Zirconium oxide nanoparticles group, highly significant increase in impact strength (7.69 Kj/m2), surface hardness (92.35) and highly significant decrease in water sorption (0.0016 mg/cm2) and water solubility (0.0013 mg/cm2).Conclusion: the use of saline coupling agent with ZrO2 and oxygen plasma treatment PE fiber provided an effective procedure for getting good bonding with the PMMA matrix to give enhanced properties for the composite

Keywords

PMMA --- UHDPE --- ZrO2 --- FTIR --- PE --- oxygen plasma


Article
Retentive forces, tensile strength and deflection fatigue of Acetal thermoplastic clasp material in comparison with cobalt-chromium alloy

Authors: Samar S. Alwan سمر علوان --- Intisar J. Ismail انتصار جميل اسماعيل
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2014 Volume: 26 Issue: 1 Pages: 59-66
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: Nowadays there is an increasing of the emphasis on aesthetic, dentist have been concerned about providing aesthetics and functional removable partial dentures to their patients and this was make the mission more difficult because of the goal now is achieving optimal aesthetic of the denture - while maintaining retentive, stable, and conservative to the health of supporting tooth and supporting tissue. The traditional use of metal clasp like cobalt-chromium, gold, stainless-steel and titanium hampers esthetics because of its obvious display conflicts with patient’s prosthetic confidentiality. Acetal resin (poly oxy methylene) may be used as alternative denture clasp material. This material was promoted primarily on the basis of its superior esthetic.Material and method: In this study, Acetal resin of Flexite and co-cr alloy of Wirocast companies were used. Four metal models of two premolars and two molars were surveyed to have 0.25mm and 0.5mm undercut depth for each one of the materials. eighty clasps were prepared and tested by testing machine to measure the load required to dislodge Acetal and co-cr clasps of 2mm. thickness (for premolar and molar). Tensile test were utilized for both Acetal resin and co-cr. tensile values will be used in special formula to calculate the amount of deflection.Results: The results of this study revealed that Acetal resin clasp of molar with 0.5mm undercut depth have the higher retentive force, and premolar with 0.25 mm undercut depth have the lowest retentive force as compared to co-cr. Also Acetal had lower values of the tensile strength as compared to co-cr alloy but it had higher deflection value than co-cr and it can withstand higher deflections than those of co-cr before having permanent deformation or fractureConclusions: Acetal resin can be used with limitation as an alternative to co-cr alloy clasps in removable partial dentures.


Article
The effect of silanized alumina nano -fillers addition on some physical and mechanical properties of heat cured polymethyl methacrylate denture base material

Authors: Ban Saad Jasim بان سعد جاسم --- Intisar J. Ismail انتصار جميل اسماعيل
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2014 Volume: 26 Issue: 2 Pages: 18-23
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: Polymethyl methacrylate (PMMA) is the most commonly used material in denture fabrication. Thematerial is far from ideal in fulfilling the mechanical requirements. Midline fracture; poor thermal conductivity andwater sorption, are common problem in this material. The purpose of this study was to evaluate the effect of additionof surface treated Aluminum oxide nano fillers on some properties of heat cured (PMMA).Materials and methods: In addition to controlled group of heat cured PMMA the silanized (Al2O3) nanoparticles wasadded to PMMA powder by weight in three different percentages 1wt%, 2wt% and 3wt%, mixed by probe ultrasonicationmachine. 200 specimens were constructed and divided into 5 groups according to the test (each groupconsist of 40 specimens) and each group was subdivided into 4 sub-groups. The tests conducted were thermalconductivity, thermal diffusivity, transverse strength, indentation hardness (shore D), surface roughness, water sorptionand solubility. The results were statistically analyzed using ANOVA and Dunntt t-test.Results: A highly significant increase in transverse strength was observed with the addition of (Al2O3) nanoparticles to(PMMA) at the percentage of 1wt%, the value was 117.72 Mpa and significant increase at 2wt%; while a significantreduction occurred in transverse strength at the percentage of 3% the value was 90.110 Mpa. A significant increasein surface hardness and non significant differences in surface roughness were observed for all percentages.Conclusion: The addition of Al2O3 nanoparticles to acrylic resin improves the thermal properties and transversestrength of acrylic resin at the same time this addition decreases water sorption and solubility


Article
Evaluation the Effect of Addition of Plasma Treated Polypropylene Fiber and Silanized Silicon Dioxide Nanoparticles Composite on Some Properties of Heat-Polymerized Polymethylmethacrylate

Authors: Ahmed G. Ahmed احمد غيث احمد --- Intisar J. Ismail انتصار جميل اسماعيل
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2016 Volume: 28 Issue: 4 Pages: 1-8
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: Polymethylmethacrylate (PMMA) is the most commonly used material in denture construction. This material is far from ideal in fulfilling the mechanical requirements, like low impact and transverse strength and poor thermal conductivity are present in this material.The purpose of this study was to study the effect of addition a composite which include 1%wt silanized silicone dioxide nano fillers (SiO2) and 1wt% oxygen plasma treated polypropylene fiber (PP) on some properties of heat cured acrylic resin denture base material (PMMA).Materials and methods: One hundred (100) prepared specimens were divided into five groups according to the tests, each group consisted of 20 specimens and these were subdivided into two groups (unreinforced heat cured acrylic resin as control group)and reinforced acrylic resin with ( 1%wt Nano SiO2 and 1% wt oxygen plasma treated polypropylene fibers) group. The transverse strength¸ impact strength, indentation hardness (shoreD), surface roughness and water sorption and solubility were investigated. The results were statistically analyzed using descriptive and t-test.Results: The results of this study show that a highly significant increase in impact strength (10.4939 Kj/m2),surface hardness (89.9375) surface roughness (0.9498) and water sorption (0.0171mg/cm2) was observed with the addition of 1%wt silanized (SiO2) nanoparticles and 1%wt oxygen plasma treated polypropylene fibers to (PMMA) , also significant decrease in transverse strength (103.4753 N/mm2), nonsignificant decrease occurred in water solubility which was (0.0005mg/cm2).Conclusion: The incorporation of 1%wt silanized SiO2 nanoparticles and 1%wt oxygen plasma treated polypropylene fiber to heat cure PMMA form a composite improves the impact strength, surface hardness and surface roughness of acrylic resin, at the same time this addition increase the water sorption and decrease water solubility; while significant decrease in transverse strength


Article
A Study the Effect of Addition of Silanized Zirconium Oxide Nanoparticles on Some Properties of High-Impact Heat-Cured Acrylic Resin

Authors: Soodad A. Al-Hiloh سوداد الحلو --- Intisar J. Ismail انتصار جميل اسماعيل
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2016 Volume: 28 Issue: 2 Pages: 19-25
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: The incorporation of rubber has not been entirely successful because it can have detrimental effectson the transverse Strength and hence the rigidity of the denture base.Materials and methods: Zirconium oxide nanoparticales were coated with a layer oftrimethoxysilylpropylmethacrylate (TMSPM) before sonication in monomer (MMA) with the percentages 3% byweight then mixed with powder using conventional procedure.(100) samples were prepared and divided into fivegroups according to the test performed ,Each group consisted of 20 specimens and these were subdivided into 2groupsGroup (A): control group (10 specimens of high impact acrylic resin without zirconium oxide) and Group(B):zirconium oxide group(10 specimens of high impact acrylic resin with 3% wt zirconium oxide).The testsconducted were impact strength, transverse strength, indentation hardness(shore D), surface roughness, watersorption and solubility. The results were statistically analyzed using Dunntt t-test.Results: Highly significant increase in impact strength and transverse strength occurred with the incorporation of 3%wt Zirconium oxide nanofiller. A highly significant increase in surface hardness, but the water sorption and solubilitywere significantly decreased with the addition of silanized (ZrO2) Nano particles compared with the control group.nosignificant statistical difference in surface roughness.Conclusions: The addition of silanized ZrO2 Nano particles to high impact heat cure acrylic resin material improves theimpact strength, transverse strength and surface hardness of high-impact heat-cure acrylic resin at the same timethis addition decreases water sorption and solubility. On the other hand there was no change in surface roughnesswith the addition of 3% wt of silanized ZrO2Nano particles

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