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Article
Influence of Magnetic Nitrogen Plasma Functionalization of High Density Polycarbonate

Authors: A.S. Jasim --- K.I. Khaleel --- M.A.K. Ahmed --- Y.K. Vijay --- et al.
Journal: Iraqi Journal of Applied Physics المجلة العراقية للفيزياء التطبيقية ISSN: 18132065 23091673 Year: 2012 Volume: 8 Issue: 4 Pages: 17-22
Publisher: iraqi society for alternative and renewable energy sources and techniques الجمعية العراقية لمصادر وتقنيات الطاقة البديلة والمستجدة

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Abstract

Low pressure nitrogen plasma has been used to modify surface properties of polycarbonate membrane. Evaluation of surface morphology changes has been carried out using atomic force microscopy (AFM). To study surface topography changes related to etching effect, the scanning electron microscopy (SEM) has been carried out. The results show a considerable improvement in surface roughness, SEM and AFM analyses show remarkable changes in surface topography as a consequence of the plasma-etching mechanism. The increasing of optical transparency of the plasma treated membranes was observed from UV-visible spectroscopy. The refractive index value for treated films has been decreased as observed from laser ellipsometry measurement. Furthermore, the changes in chemical bonds for polymer films were studied. It is found that plasma treatment can change chemical structure of polymer surfaces partially.


Article
The effect of plasma treatment on the bonding of soft denture liners to heat cured acrylic resin denture base material and on some surface properties of acrylic resin polymer

Authors: Shaymaa H. Masood شيماء مسعود --- Salah A. Mohamed صلاح محمد
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2012 Volume: 24 Issue: 3 Pages: 29-35
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: Acrylic resin polymers used in dentistry, are usually with problems in bonding, especially failure of thebond with soft denture lining materials. The aim of this study is to investigate the effect of plasma treatment on tensilebond strength, wettability and on physical surface changes for acrylic resin polymer.Materials and methods: Heat cured acrylic resin specimens with dimensions 8×10×30 mm were prepared for tensilebond strength test, in which each two acrylic specimens were joined by a 3-mm thick soft liner (Vertex Soft,Molloplast-B). Another heat curd acrylic resin specimens were prepared with dimensions 2×8×30 mm for wettabilitytest and physical surface analysis. For each test done in this study, the specimens were grouped as control, oxygenplasma treated and argon plasma treated acrylic specimens.Results: Plasma treatment increased the tensile bond strength for both Vertex and Molloplast-B soft lining materials,also induced a decrease in water contact angle values (i.e., increase in wettability) for oxygen and argon plasmatreated groups compared with control group, with highly significant difference (P <0.01) among groups. AFM imagesshowed a collection of new distinct nanograins and numerous grooves (pitlike-structures) after oxygen and argonplasma treatment with argon plasma treatment showed more new nanograins, deepest grooves and highestprotuberances which increased the surface-roughness (i.e. nano-roughness) when compared with control andoxygen plasma treated groups.Conclusion: Plasma treatment was an effective method for increasing tensile bond strength, wettebility, and inducedphysical topographical surface changes that increased the surface roughness(mainly after argon plasmatreatment) for plasma treated heat cured acrylic resin specimens


Article
Effect of plasma treatment of acrylic denture teeth and thermocycling on the bonding strength to heat cured acrylic denture base material

Author: Hikmat J. Aljudy حكمت جميل الجودي
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2013 Volume: 25 Issue: special issue 1 Pages: 6-11
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: Acrylic resin polymer s used in prosthodontic treatment as a denture base material for several decades.Separation and debonding of artificial teeth from denture bases present a laboratory and clinical problem affectpatient and dentist. The aim of this study is to evaluate the effect of oxygen plasma and argon plasma treatment ofacrylic teeth and thermocycling on bonding strength to hot cured acrylic resin denture base material.Materials and Methods: Sixty denture teeth (right maxillary central incisor) are selected. The denture teeth are waxedonto the beveled surface of rectangular wax block according to Japanese standard for artificial teeth. The controlgroup consisted of 20 denture teeth specimen without any treatment. The oxygen plasma group consisted of 20denture teeth specimen treated with oxygen plasma for two minutes exposure time at plasma apparatus. The argonplasma group consisted of 20 denture teeth treated with argon plasma for two minuets exposure time. All thespecimens are undergone flasking and wax elimination procedure in the conventional way. All specimens stored indistilled water for 7 days at 37°C, then half of the specimens of all groups undergoes thermocycling between 5°C -55°C in 60 seconds cycles for three days and tested for shear bond strength using universal testing machine the datawas collected and analyzed statistically using analysis of variance and independent sample t-test.Results: The plasma treated groups showed the higher mean force required to fracture the acrylic teeth from theirheat cured acrylic resin denture bases, as compared to control group, and the oxygen plasma treatment groupshowed higher shear bond value than the argon plasma treatment. The thermocycling had a deleterious effect onbonding strength for control group while the plasma treated group showed an increase in bond strength followingthermocycling.Conclusion: Plasma treatment method was an effective approach for increasing the shear bond strength as a resultof surface oxidation and chemical etching effect of oxygen plasma and micromechanical interlocking effect ofargon plasma


Article
The effect of addition of untreated and oxygen plasma treated polypropylene fibers on some properties of heat cured acrylic resin

Authors: Waffaa I. Mohammed --- Intisar J. Ismail
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2013 Volume: 25 Issue: 4 Pages: 33-38
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: The polymethyl methacrylate is the most reliable material for the construction of complete and partialdentures, despite satisfying esthetic demand itsuffered from having unsatisfactory properties like impact strength andtransverse strength.This study was designed to improve the impact strength and transverse strength of heat cure acrylic resin by addinguntreated and oxygen plasma treated polypropylene fibers and investigate the effect of this additive on someproperties of acrylic resin materials.Materials and methods: Untreated and oxygen plasma treated polypropylene fibers was added to PMMA powderby weight 2.5 %. Specimens were constructed and divided into 5 groups according to the using tests; each groupwas subdivided in to 3 subgroups. The tests conducted were impact strength, transverse strength, surface hardness,surface roughness, water sorption and solubility. Data were analyzed by one way analysis of variance (ANOVA) andleast significant differences (LSD).Results: After incorporation of untreated and oxygen plasma treated polypropylene fibers there was a highlysignificant increase in impact strength and surface hardness; while there was a non significant difference intransverse strength. Also the value of water sorption increase significantly but with the limit of ADA specification.Conclusion:Within the limit of this study it can be concluded that the reinforcement with polypropylene fiberseffective method to increase fracture resistance of denture base; while reinforcement with oxygen plasma treatedpolypropylene fibers further increase fracture resistance


Article
Surface Roughening of Poly (methyl-methacrylate) Membranes by SF6-Glow-Discharge Plasma Etching
زيادة خشونة سطح غشاء البولي-ميثاكريلايت باستخدام بلازما التفريغ الكهربائي التوهجي لغاز سادس فلوريد الكبريت

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Abstract

The (100 μm) thick of high density Polymethylmethacrylate PMMA membranes were prepared by solution cast method and treated by (42 W), low pressure, DC-discharge, SF6-Plasma for different exposure time: 10,30,60 and 80 min. The observed changes in membranes surface properties have been characterized by Scanning Electron Microscopy(SEM).The optical properties for plasma treated membranes has been characterized by UV-Visible Spectroscopy. The chemical structure changes have been characterized by Fourier Transformation Infrared Spectroscopy (FTIR).The (SEM) results indicates to significant changes in surface morphology of the polymer membranes after plasma treatment. The UV-Visible spectroscopy results shows clearly reduction of light transmission due to plasma treatment, also the (FTIR) results shows the changes in molecular bonds for polymer chains in surface structure of polymer membranes.

في هذا العمل تم تحضير أغشية بوليمر البولي - ميثاكريلايت عالي الكثافة بسمك (100µm) باستخدام طريقة ترسيب المذيب ، وتم معاملة هذه الأغشية ببلازما التفريغ الكهربائي لغاز سادس فلوريد الكبريت (SF6) بضغط منخفض وبقدرة تفريغ كهربائي تبلغ (42W).وتم اختيار زمن معاملة يبلغ (10,30,60,80) دقيقة. وتم تسجيل التغييرات الحاصلة في خصائص سطح اغشية البوليمر باستخدام المجهر الإلكتروني الماسح. وتم تسجيل التغييرات الحاصلة في خصائص السطح البصرية نتيجة التعامل بالبلازما باستخدام المطياف الضوئي. وكذلك تم تسجيل التغييرات الجزيئية الكيمياوية في خصائص سطح غشاء البوليمر باستخدام مطياف فوريير للأشعة تحت الحمراء.ولقد اشارت نتائج المجهر الإلكتروني الماسح الى حدوث تغييرات ملحوظة في خشونة سطح غشاء البوليمر بعد معاملته ببلازما التفريغ الكهربائي ذات الضغط المنخفض. وكذلك أظهرت نتائج المطياف الضوئي تناقص في نفاذية الضوء للغشاء المعامل بالبلازما. وكذلك أشارت نتائج مطياف فوريير للأشعة تحت الحمراء الى تغييرات في الاواصر الجزيئية لسلاسل البوليمر في سطح الغشاء نتيجة عملية كسر الاواصر وعملية الربط البيني في بنية سلاسل البوليمر.


Article
Influence of non-thermal argon plasma needle on blood coagulation
تأثير بلازما الأركون غير الحرارية على تخثر الدم

Authors: Kadhim A. Aadim كاظم عبد الواحد عادم --- Heba R. Najem هبه رياض نجم
Journal: Iraqi Journal of Physics المجلة العراقية للفيزياء ISSN: 20704003 Year: 2016 Volume: 14 Issue: 29 Pages: 101-106
Publisher: Baghdad University جامعة بغداد

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Abstract

Non-thermal argon plasma needle at atmospheric pressure was constructed. The experimental setup was based on a simple and low cost electric component that generates a sufficiently high electric field at the electrodes to ionize the argon gas which flow at atmospheric pressure. A high AC power supply was used with 1.1 kV and 19.57 kHz. Non-thermal Argon plasma used on blood samples to show the ability of non-thermal plasma to promote blood coagulation. Three tests have been done to show the ability of plasma to coagulate both normal and anti-coagulant blood.Each blood sample has been treated for varying time from 20sec. to 180sec. at different distances. The results of the current study showed that the cold plasma produced from argon significantly increase the in vitro speed of blood coagulation, the plasma increases activation and aggregation of platelets, causes proliferation of fibroblasts and fibrin production accelerates blood coagulation.

تم تكوين أبره أركون بلازما غير الحرارية عند الضغط الجوي. واستندت الإعدادات التجريبية على مكونات كهربائية ذات تكلفة بسيطة ومنخفضة تعمل على توليد حقل كهربائي عالي عند الأقطاب لتأين غاز الاركون المستخدم الذي يتدفق عند الضغط الجوي. تم استخدام مجهز قدرة عالي ذو تيار متردد AC عند القيمة 1.1كيلوفولت وبالتردد19.57كيلوهيرتز.كما تم استخدام بلازما الاركون غير الحراريه في اظهار قدرتها على تخثر الدم.حيث اجريت ثلاث تجارب لاظهار قدرة البلازما على تخثير الدم الاعتيادي والدم المضاف له مانعات تخثر كل عينة دم تم معالجتها بزمن يتراوح مابين 20ثانية الى 180ثانية وعند مسافات مختلفة. النتائج اظهرت ان البلازما الباردة لها القدرة على تخثير الدم خارج الجسم خلال فترة قصيرة وكذلك تعمل على تفعيل تجمع الصفائح الدموية وتسريع انتشار الخلايا الليفية وبالتالي انتاج الفايبرين الذي يسرع تخثر الدم.


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
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
The effect of plasma treatment on shear bond strength of soft denture liner with two different types of denture base material (heat cure and light cure)

Authors: Zainab S. Abdullah زينب عبد الله --- Wasmaa S. Mahmood وسماء محمود --- Rafah A. Ibrahem
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2014 Volume: 26 Issue: 2 Pages: 44-49
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: In this study we evaluate the effect of plasma treatment (oxygen and argon) gas in two differentexposure times on the surface of heat cure and light cure acrylic resin.Materials and method: 100 specimens of heat cure and light cure acrylic resin were fabricated. The measurements ofthe samples were (75mm, 25mm and 4.5mm) length, width and depth respectively with stopper of 3mm depth. Twotypes of gas used oxygen and argon in (5,10) min by using (DC-glow discharge plasma device) then we apply coldcure soft lining material, with the help of Instron machine we test the shear stress value.Results: A highly significant effect after argon and oxygen gases treatment in both 5 and 10 min exposure times onshear bond strength to soft liner in heat cure denture base material.Conclusion: In this study we found that the exposure of heat cure acrylic resin to plasma gases (argon and oxygen)increase the shear bond strength (SBS) values significantly


Article
The Effect of Plasma Treatment on Shear Bond Strength of High Impact Acrylic Resin Denture Base Lined with Two Types of Soft Lining Materials after Immersion in Distilled Water and Denture Cleanser

Authors: Shahad Basim Mustafa شهد باسم مصطفى --- Thekra Ismael Hamad ذكرى اسماعيل
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2015 Volume: 27 Issue: 4 Pages: 44-51
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: In dentistry, dentist takes the advantages of soft lining materials due to the viscoelastic properties. Themajor problem is the adhesion of the soft liner with the denture base material.Materials and Methods: Heat cured of high impact acrylic resin specimens prepared with dimensions 75x13x13mm forshear bond strength test, soft lining material (Refit and Mollosil) with a 3-mm thickness and used to join each twoacrylic blocks. Also four specimens with the same previous dimensions utilized for chemical and physical surfaceanalysis. The specimens grouped as control (without plasma) and experiment (with oxygen plasma) treated highimpact acrylic specimens.Results: Plasma treatment increased the shear bond strength for both Refit and Mollosil soft lining material afterimmersion in distilled water for 30 days as compared with the control group, also there was decrease in shear bondstrength for both Refit and Mollosil soft lining material of the experimental group after immersion in denture cleanserfor 30 days as compared with the control (without plasma treated) group. AFM analysis revealed that oxygenplasma treatment led to formation of (pits and protuberances) that increase the surface area and increase theshear bond between soft liners and high impact acrylic denture base.Conclusions: Oxygen plasma surface treatment was an effective method for increasing adhesion by physicaltopographic surface (due to the plasma etching process which in turn led to removal of some material from thesurface and this led to increase the bond strength).

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