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Article
Testing Different Properties of A Light-Cured Denture Base Material After Addition of Silicon Oxide Nanofiller (An in Vitro Study)

Author: Mohammed Moudhaffer M Ali
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2017 Volume: 29 Issue: 1 Pages: 47-54
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: Improving the properties of heat- cured and self-cured acrylic resin have been studied by many researchers. However, little studies concerned with visible light cured resin (VLCR) improved through addition of nanofiller are available. The purpose of this study was to evaluate some properties of (VLCR) after addition of SiO2 nanofiller.Materials and Methods: SiO2 nanofiller were added to (VLCR) tray material after being dissolved in tetrahydrofuran (THF) solvent. According to the pilot study 2% SiO2 nanofiller addition exhibited better properties than the other percentages (1%, 3%). The main study conducted involved (100) specimens divided into 5 groups according to the test included. (20) Specimens were selected for each test (10 samples for the control group and 10 samples for the experimental 2% SiO2 nanofiller group). The properties investigated were transverse strength, impact strength, surface hardness, surface roughness, water sorption and solubility. Scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS) were used to assess nanofiller distribution and identification of elements. The data were subjected to descriptive statistical analysis and independent sample t-test.Results: The mean value of transverse strength of experimental group increased significantly, while the impact strength of experimental group decreased significantly when compared to control group. A significant increase in surface hardness was noticed in the experimental group, while non-significant increase in surface roughness was observed. The water sorption values were decreased significantly, while a non-significant decrease in water solubility was observed in the experimental group.Conclusion: Addition of SiO2 nanofiller to (VLCR), slightly improve the transverse strength and surface hardness, while water sorption and solubility slightly decreased. The impact strength was significantly deteriorated, while the surface roughness shows non-significant increment


Article
KINETIC STUDY OF PHOTODEGRADATION OF Azo DYES WITH TiO2 UNDER VISIBLE LIGHT

Authors: Hassan A. Habeeb --- Abbas A. A. Kadhum
Journal: Al-Nahrain Journal of Science مجلة النهرين للعلوم ISSN: (print)26635453,(online)26635461 Year: 2010 Volume: 13 Issue: 3 Pages: 41-50
Publisher: Al-Nahrain University جامعة النهرين

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Abstract

In this work, two mono azo dyes : 4-(2- benzoic acid azo )-m-amino phenol (BAMAP), and4-(2-benzoic acid azo)-P-amino phenol (BAPAP)have been synthesized and identified by FT-IRspectroscopy. UV-Visible absorption spectra were recorded and some physical and chemicalproperties have been listed.The photodegradation of dyes was investigated by using the light of tungsten lamp in presenceand absence of titanium dioxide (anatase). It has been found that the increasing of TiO2 masscaused an increasing in photodegradation of two dyes until the optimum mass (2gm/l) was reached.Also, the results indicate, that the basic media give more photodegradation rate than acidic medium,moreover ,the effect of temperatures in the range (298 323K) on degraded dye was studied ,and theactivation energy of photodegradation processes was calculated from Arrhenius plot which equal35.82KJ.mol-1for BAMAP and 32.11KJ.mol-1for BAPAP.The results showed the photoreaction is1st order ,with decomposition constant equal 2.362x10-4min-1for BAMAP and 2.826x10-4 min-1forBAPAP at 298k and neutral medium.Generally, it has been found that the rate of photodegradation of BAPAP is more than BAMAP,and the decolonization rate of the two dyes was higher in presence of TiO2 suspension.

يتضمن البحث تحضير صبغتي ازو أحادية وهما(PAPAP) -2 حامض البنزويك ازو ) بارا امينو فينول )-42- حامض البنزويك ازو ) ميتا امينو فينول )- و 4تم تشخيص الأصباغ المحضرة بوساطة . (PAMAP)مطيافية الأشعة تحت الحمراء. و سجلت كذلك أطيافالأشعة المرئية وفوق البنفسجية وتم دراسة بعض الخواصالفيزيائية والكيميائية .وتضمن البحث كذلك دراسة التحطم الضوئي للأصباغالمحضرة بوساطة استخدام ضوء من مصباح مرئي بوجودوغياب عالق ثاني اوكسيد التيتانيوم (الانتيز) .وجد إنأدت إلى زيادة سرعة التحطم الضوئي TiO زيادة تركيز 2TiO لكلا الصبغتين لحين الوصول إلى التركيز الأمثل ل 2وهو 2غم/لتر . ودلت النتائج أيضا بان المحيط القاعدي قدحفز من سرعة التحطم الضوئي أكثر بالمقارنة مع المحيطألحامضي .درس تأثير درجة الحرارة ضمن المدى - 323298 كلفن حيث وجد آن درجات الحرارة العالية أدت إلىزيادة سرعة تحطم الصبغتين ووجد إن طاقة التنشيط كانتو PAMAP 35.82 كيلو جول/مول للصبغةللصبغة.دلت PAPAP 32.11 كيلو جول/مول للصبغةالنتائج بان التفاعل الضوئي المحفز تبع حر كيات منالمرتبة الأولى ووجد أن ثابت سرعة التفككو PAMAP 2.362 للصبغة x 10-4 min-1. PAPAP 2.826 للصبغة x 10-4 min-1و بصورة عامة وجد بان سرعة التحطم الضوئي، BAMAP كانت أعلى من الصبغة BAPAP للصبغةكذلك فان سرعة إزالة اللون لكلا الصبغتين كانت أعلى. TiO بوجود عالق 2


Article
Comparison the tensile strength of heat cure and visible light cure acrylic resin denture base

Authors: Zahraa N. Al- Wahab زهراء الوهب --- Bassam A. Hanna بسام حنا --- Shakwaan K. Kadir شاكوان قادر
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2012 Volume: 24 Issue: special issue 1 Pages: 44-47
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: Visible light cured acrylic resin denture materials are one of the developed polymeric acrylic denturebase and are manufactured in the form of sheets and rapes, and also in powder and liquid system, they can beadapted for various dental uses and provides rapid service at low cost. This study aimed to compare the tensilestrength of heat cured acrylic resin and visible light cured acrylic resin.Materials and Methods: Twenty samples of acrylic denture base materials were prepared, ten samples of heat curedacrylic denture base materials and ten samples of visible light cured acrylic denture base material. After curing ofboth groups, the materials were subjected to tensile strength test with the use of Instron universal testing machine.Results: The results of the present study showed a high significant difference comparing between the two groups;heat cured acrylic denture base material showed a high significant tensile strength than the visible light cured acrylicdenture base material.Conclusion: heat cured acrylic denture base resin showed superiority in the tensile strength values than the visiblelight cured acrylic denture base material


Article
Visible Light Photocatalytic Decolourization of Methyl Orange Using N-Doped TiO2 Nanoparticles

Authors: Hussein M. Hadi --- Hilal S. Wahab
Journal: Al-Nahrain Journal of Science مجلة النهرين للعلوم ISSN: (print)26635453,(online)26635461 Year: 2015 Volume: 18 Issue: 3 Pages: 1-9
Publisher: Al-Nahrain University جامعة النهرين

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Abstract

In the present study, nitrogen doped TiO2 (N-TiO2) has been synthesized by simple sol-gel technique. The light absorption property and morphology of the N-TiO2 were characterized by Diffused Reflectance UV-VIS spectrometer and scanning electron microscopy (SEM). The results showed a clear shift in the light absorption from UV region (380) to visible region (410 nm). SEM results showed the morphology was changed after doping process compared with the pure anatase TiO2. The photocatalytic activity was examined by the photo decolorization of the Methyl Orange which was used as a pollutant model in this study under visible light irradiation. The main operational parameters, namely, initial pollutant concentration, doped photocatalyst loading, pH of photocatalysis solution and visible light intensity on the rate of photocatalytic decolorization. The results show that N doping induced the enhancement of photocatalytic decolorization. Methyl orange removal efficiency results at optimum experimental conditions have revealed more than 98% degradation after 60 minutes of illumination.

حُضر مسحوق ثنائي اوكسيد التيتانيوم النانوي المشوب بذرات النتروجين مختبريا باستخدام طريقة سول-جل واُختبرت كفائته بإزالة لون صبغة المثيل البرتقالي تحت الضوء المرئي. لقد اُستخدمت تقنية المجهر الإلكتروني الماسح لدراسة طوبوغرافية السطح والتحليل الطيفي الانعكاسي في مجال الاشعة المرئية وفوق البنفسجية لحساب طاقة الفجوة والمساوية إلى 3.02 إلكترون فولت (410 نانوميتر) مقارنة بطاقة الفجوة لثنائي أوكسيد التيتانيوم القياسي (الانتيز) المساوية إلى 3.26 إلكترون فولت (380 نانوميتر). تم دراسة المؤثرات التشغيلية الرئيسة على عملية القصر مثل التركيز الابتدائي للصبغة ، كمية المسحوق النانوي، الدالة الحامضية للوسط وشدة الضوء المرئي. بينت النتائج الدور الايجابي للتشويب في عملية قصر الصبغة وصولا إلى تحطيم أكثر من 98% منها خلال فترة 60 دقيقة من التعرض للضوء المرئي. كما وجد إن هذه النتائج تتفق بشكل كبير مع نتائج البحوث الأخرى.


Article
Evaluation of Dimensional Stability for Denture Bases in different Curing Techniques

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Abstract

Stable record base is critical for recording an accurate maxillo-mandibular relationship and evaluation of the esthetics and phonetics of the wax trial prosthesis. To ensure intra-oral stability and retention of the record base, the base should maintain close adaptation to the cast and be dimensionally stable, this study compare the dimensional stability of visible light cure acrylic both conventionally and by using new technique of short curing cycle. Thirty maxillary cast edentulous models poured with a type IV dental di-stone, the specimen divided into three subgroups each group consist of ten cast. In the first group denture base constructed from heat cure acrylic resin using short curing cycle, while in the second group it constructed by using visible light cure acrylic resin and for the third group from visible light cure acrylic resin using new technique, the gap space occurs between the denture base and the cast measured by using traveling microscope measuring device. In this study the reading for the gap space occur between the denture base and the cast show that significantly both the short cycle and VLC new technique more dimensionally stable than that of VLC conventional technique when compared by ANOVA Table and LSD multiple comparison. The dimensional accuracy or fit for the denture base improved by using either a heat cured acrylic resin (using short curing cycle or by using light activated poly methylmethacrylate with the aid of new technique so that better stability and retention of the record bases obtained.


Article
Visible Light Cure Fiber Frame Work Reinforcement of Acrylic Resin Denture Base Material. A Comparative Study.

Author: Aliaa W AL-Omari
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2014 Volume: 14 Issue: 2 Pages: 173-181
Publisher: Mosul University جامعة الموصل

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Abstract

Aims: Heat cured acrylic resin is the material of choice for construction of complete dentures due to its desirable properties, although it has some disadvantages as its susceptibility to fracture. Several methods and materials are used to reinforce acrylic resin denture base. One of these methods is reinforcement by using fibers. In this study, visible light cure fiber frame work is used as reinforcement material and compared with reinforcement with glass fiber. Materials and methods: in this study, 128 samples were prepared for evaluation of transverse strength, impact strength, surface hardness, and residual monomer tests. The samples were divided into four groups 8 sample for each group; control group without reinforcement, reinforcement by using visible light cure fiber frame work, random glass fiber reinforcement, and mesh glass fiber reinforcement. Results: the results of this study showed that visible light cure fiber frame work system significantly increase the transverse strength and impact strength of the heat cured acrylic resin, and it didn’t affect the surface hardness and amount of residual monomer of heat cured acrylic resin. Conclusions: visible light cure fiber frame work system increase acrylic resin denture base resistance to fracture.

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