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Article
Filler reinforced acrylic denture base material. Part 2- Effect of water sorption on dimensional changes and transverse strength

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Abstract

Background: PMMA considered the most commonly used for complete dentures. It absorbs a small amount of water which exerts significant effect on its properties. Effect of water on dimensional changes and transverse strength of filler reinforced PMMA were investigated in this study.Materials and methods: Different types of fillers were used: Kevlar (6%), glass fibers (5%) by weight in mat and unidirectional forms, zirconium oxide particles (5%) were used, which was added to acrylic resin. The dimensional changes: after processing, drying, and immersion in water for one month were measured. Transverse strength was measured for three periods (after deflasking, after two days, and after one month in water).Results: least dimensional changes was observed in samples with Kevlar unidirectional, they cause about 75.18% reduction in shrinkage, while with glass unidirectional cause 48.33%. A significant reduction in shrinkage was observed with Kevlar and glass reinforced samples in mat form. The addition of Kevlar unidirectional into acrylic resin caused an increase in transverse strength of about (18.5%) after deflasking, and (14%) after one month in water, the decrease in strength in this group after one month in water was about 12.9% when compared to that after deflasking. The transverse strength of samples with zirconia results in slight decreased in strength but was non significant.Conclusion: The presence of fibers decreases the dimensional changes, and fiber form had an effect on it. The transverse strength of PMMA was increased by the presence of fibers. The strength decreased with water immersion, but fiber reinforced samples remain of higher strength.

Keywords

filler --- acrylic --- dimension --- strength


Article
Cranioplasty ( Monomeric Acrylic Designed in Dental Laboratory Versus Methylmethacrylate Codman's Type)

Authors: Yasir M H Hamandi --- Abdulameer Jasim Al-Khafaji --- Ihssan S.Nema
Journal: Iraqi Academic Scientific Journal المجلة العراقية للاختصاصات الطبية ISSN: 16088360 Year: 2011 Volume: 10 Issue: 2 Pages: 198-203
Publisher: The Iraqi Borad for Medical Specialization المجلس العراقي للاختصاصات الطبية

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Abstract

ABSTRACT:BACKGROUNDCranioplasty is a surgical procedure for closure of skull defect either duo to traumatic or non traumatic causes, using a synthetic or natural materials for repairMETHODS:14 patients collected from AL-Kadhimiya teaching hospital ,complaining of skull defect ,12 males,2 females. 8 patients had history of bullet injury.RESULTS:Surgery done for all using methylmethacrylate Codman's type for 8,the other 6, monomeric acrylic designed in the hospital.1 patient had history of loss of consciousness postoperatively, 1 patient had postoperative dizziness, mild improvement of headache in two patients.CONCLUSION:Monomeric acrylic designed preoperatively decreasing the time of surgical maneuvere


Article
Measuring the Shear Bound Strength on Acrylic Resin Veneer to Metal Surface of Nickel (A Comparative Study)

Author: Aklas Zeid Abood اخلاص زيد عبود
Journal: Tikrit Journal for Dental Sciences مجلة تكريت لعلوم طب الاسنان ISSN: 20731213 Year: 2016 Volume: 4 Issue: 2 Pages: 141-148
Publisher: Tikrit University جامعة تكريت

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Abstract

The bound strength of metal resin interface of prosthesis is a keyfactor in determining the service ability of that prosthesis. Themain objective of this study was to determine the effect ofdifferent surface treatment on the shear bond strength of Ni-Cralloy (CB-Blando 72 alloy) and heat cured acrylic veneer resin(Vertex).Thirty disc shaped samples from base plate wax were prepared,the diameter of disc was (8 mm x 4.5 mm). After casting themetal, the samples were cleaned, finished and polished by siliconcarbide abrasive paper with grit size (600 μm) and then theprofilometer was used to determine the surface roughness ofsamples. Then the samples were divided in to three groups, eachgroup contain (10) samples.The first group received no treatment and serve as control .TheSecond group received micro mechanical treatment using 250 μmAl2o3 .The third group recived micro mechanical treatment using400 μm Al2o3. The acrylic was prepared as a round shape (8 μm) indiameter and (2 μm) in thickness, which was placed on the metalsurface treatment, the acrylic was fabricated in the sameconventional way for construction veneer resin. Then all sampleswas tested the shear bond strength by using Instron universaltesting machine .The result from this study showed that, the firstgroup was give low shear bond strength while the second groupshowed that the air abrasion with 250 μm Al2o3 give the highestshear bond values when compared with the third group which airabrasive with 400 μm Al2o3.

Keywords

Acrylic --- bound strength --- nickel


Article
The Effects of Magnetic Resonance Imaging (MRI) On Tensile Strength and Indentation Hardness of Acrylic Resin Denture Base Materials

Authors: Ahmed I. Al-Khyeet --- Ammar Kh. Al-Noori --- Amer A. Taqa
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2015 Volume: 15 Issue: 2 Pages: 399-404
Publisher: Mosul University جامعة الموصل

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Abstract

Aims: This study aims to evaluate the effect of (MRI) on physical, and mechanical properties of acrylic resin denture base materials. Materials and Methods: one hundred and ten samples were the total no. of samples, samples were divided into two groups each group contain two fifty five, the 1st sample group pink and 2nd groups clear heat cured acrylic resin, then the two groups is divided into four sub-groups, follow that the samples were exposed to magnetic resonance image at three different peri-ods of time (5, 15, 30) minutes within control group respectively and samples tested for indentation hardness, tensile strength. Results: the results obtained to show that there was a change in the physical properties “heat cured” acrylic resin weather it is “Pink” or “Clear” after exposure to (MRI) and this change happened at different levels and variable degree, also it has shown that there was a slight tendency to change order of a arrangement of atoms within each molecules with no well and clear evidence of altering of the main material itself, at least at circumstances of experiment. Conclusion: Exposure to (MRI) at different periods of time lead to altering of physical properties and at different levels of significant.


Article
The effect of addition chlorhixidine gluconate (powder) on the properties of heat cured acrylic resin

Authors: Alia'a W. Alomari --- Nada Z. Mohammed --- Amer A Taqa
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2011 Volume: 11 Issue: 3 Pages: 25-34
Publisher: Mosul University جامعة الموصل

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Abstract

Aims of the Study: The current study aims to evaluate the effect of the addition of chlorohexidine gluconate (CHX) (powder) on some physical , mechanical properties and antimicrobial effect. Materials and Methods: In this study two hundred and forty samples of heat cured acrylic resin (Major base-2) were prepared and divided into: control group( without the addition of CHX) and experimental groups(with the addition of CHX(powder) at (1%, 2%, 3%)) to evaluate transverse strength, tensile strength, , surface hardness, dimensional accuracy, deflection , residual monomer in addition to antimicrobial effect for heat cured acrylic resin before and after the addition of CHX(powder). Results: Results showed a statistically significant difference at (p0.05) between control and experimental groups. The addition of CHX (powder) into heat cured acrylic resin increases its flexibility in addition to it's antimicrobial effect. Group of 1% CHX has the highest value of transverse strength, tensile strength ,surface hardness and dimensional accuracy after control group. Conclusions: In addition to its antimicrobial effect, CHX increases the flexibility of heat cured acrylic resin. As the concentration of added CHX increased, the flexibility of heat cured acrylic resin specimens will be increased

Keywords

CHX --- acrylic resin --- flexibility


Article
Effect of using two packing Technic on Hardness of two dental acrylic resin

Author: Najim O. Nasser
Journal: nursing national Iraqi specility المجلة العراقية الوطنية للعلوم التمريضية ISSN: 18122388 Year: 2012 Volume: 25 Issue: 1 Pages: 12-18
Publisher: Baghdad University جامعة بغداد

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Abstract

Objective: the aim of this study is to invest age and determine the effect of using (2) packing technique (conventional and new tension technique) on hardness of (2) types of heat cure acrylic resin which are (Ivoclar and Qual dental type). Methodology : this study was intended the using of two types of heat cure acrylic (IVoclar and Qual dental type) which are used in construction of complete denture which packed in two different packing technique (conventional and new tension technique) and accomplished by using a total of (40) specimens in diameter of ( 2mm thickness, 2 cm length and 1 cm width) . This specimens were sectioned and subdivide into (4) group each (10) specimens for one group , then signed as (A, Al B , B 1) according to the method of technique and type of acrylic that used . The hardness of the specimens were measured by shore hardness test in technology university, Baghdad. Results: this study revealed that the type of acrylic which packed by new tension technic had less effect by hardness in compared with conventional packing technic, the result also showed that the type of acrylic resin have a little effect on hardness of the two types, and also it show highly mean value of hardness was indicate in Qual dental type in conventional technique, while the least mean value of hardness showed in Ivoclar type in new tension technique. Recommendations : this study has been conducted as a preliminary for future studies to give a sit of about the effect of hardness on other types of commercial heat acrylic resin that used in construction of prosthodontics restoration and dented prosthesis, it necessary to evaluate the hardness of any material used in construction of denture bases , it is suggested to under take a farther studies about using advance technique and better apparatus and device in packing the acrylic material and measured the value of hardness and its effect on this material.

الهدف : تهدف الدراسة الى بيان مدى تأثير طريقتي تعليب ( الطريقة العادية للتعليب ثم طريقة الضغط الجديد ) على نوعين من مادةة الاكريلك الحار المستخدم في صناعة طقوم الأسنان وهما ( الإيفوكلار والكويل دينتل) على صلادة هذين النوعين من المادة . المنهجية : أجريت الدراسة باستخدام نوعين من مادة الاكريلك الحار المستخدم في تصنيع الطقوم نوع (الإيفوكلار) ثم نوع ( الكوايل دينتل) ثم تعليب هذين النوعين بطريقتين مختلفتين ، بالطريقة العادية لتعليب المادة أولاً ثم باستخدام جهاز الضغط الجديد ثانياً . تمت الدراسة باستخدام (40) عينة ونموذج بابعاد (2 ملم سمك ، 2 سم طول ، 1 سم عرض ) للعينة ، وزعت إلى اربع مجاميع بواقع (10) عينات لكل مجموعة ، وزعت المجاميع الاربعة وفق التأشيرات حسب طريقة التعليب المستخدمة ونوع الأركيلك المستخدم والطريقة المستخدمة .تم قياس الصلادة بمقياس شور للصلادة الجامعة التكنولوجية – بغداد . النتائج : اظهرت نتائج الدراسة التي خضعت للتحليل الإحصائي ان مادة الاكريلك المعلبة بنظام الضغط الجديد قليل التأثير على صلادة المادة في الطريقة العادية وأن لا تأثير على نوع الاكريلك المستخدم في الطريقتين كذلك بينت الدراسة ان اعلى قيمة لمتوسط الصلادة ظهرت في الطريقة العادية بينما اقل معدل للصلادة في الطريقة الاخرى كذلك تبين من الدراسة ان اعلى قيمة لمتوسط الصلادة ظهر في نوع ( الكوايل دينتل) في الطريقة العادية في حين معدل الصلادة لنوع (الإيفوكلار) كان بنسبة أقل . التوصيات : هذه الدراسة اعدت لتكون تمهيداً لسلسلة من الدراسات المستقبلية لبيان مدى تأثير الصلادة على أنواع اخرى من مادة الاكريلك التجاري المستخدم في صناعة الاسنان وإيجاد طرق أخرى مستحدثة لتعليب المادة باستخدام تقنيات حديثة. ونقترح تجهيز مختبرات صناعة الاسنان بأجهزة حديثة واستخدام التقنيات العالية في جميع مراحل وخطوات اعمال مادة الاكريلك المستخدمة في صناعة طقوم الاسنان وطرق قياس وتأثير خاصية الصلادة على هذه المادة .


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
Effect of Conventional Polishing Procedure in Water Sorption of Cold and Heat Cured Acrylic Denture Base Material

Author: Azad Mohammed Ridha Al-Muthaffer
Journal: Medical Journal of Babylon مجلة بابل الطبية ISSN: 1812156X 23126760 Year: 2016 Volume: 13 Issue: 2 Pages: 481 -488
Publisher: Babylon University جامعة بابل

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Abstract

Acrylic resin is almost universally for partial or complete denture base construction due to its favorable properties. Unfortunately some disadvantages such as water sorption have been reported which causes dimensional changes that may subject the acrylic denture base to internal stresses, so the water sorption is a physical property of importance. Forty square shaped specimens (twenty specimens for heat and cold cured acrylic material) were prepared. Ten specimens from heat cured acrylic (HP) and cold cured acrylic (CP) material were polished, and ten specimens from heat cured acrylic (Hx) and cold cured acrylic (Cx) were not polished as control group. At room temperature, all specimens were weighed; this weight value was considered the initial weight of the specimen (W0). All specimens were kept in distilled water bath for 24 hours, and then specimens were weighed(W1)then the specimens were kept out of water bath for 24 hours to dry to (W0), and all samples return back to water bath for 24 hours to weigh again (W2). This manner was repeated till (W4).There is a significant difference (p=0.018) between (CP) and (Cx) and a significant difference (p=0.047) between (HP) and (Hx) and no significant difference between cold and heat cured acrylic before (p=0.699) and after polishing (p=0.52) at (p ≤0.05).


Article
Modified Processing Technique for Acrylic Resin Denture Base

Author: Ibrahim H. Alfahdawi ابراهيم حمد مخلف
Journal: Tikrit Journal for Dental Sciences مجلة تكريت لعلوم طب الاسنان ISSN: 20731213 Year: 2018 Volume: 6 Issue: 1 Pages: 28-32
Publisher: Tikrit University جامعة تكريت

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Abstract

Modified flasking technique for acrylic resin denture base at sandy stage. The uniform denture base plate wax pattern was made on the stone casts with a thickness of 3 mm. For the flow of acrylic on ridge, the necks of teeth were slight grinded from palatal or lingual surfaces toward buccal surface to allow more space. The volume of the definitive casts must be reduced as much as possiblebefore flasked in the lower part of the traditional flasks and fill with dental plaster (class II) covering the buccal, labial, incisal and occlusal surfaces of the teeth to give more support and prevent teeth migration. After curing cycle, the denture bases are carefully deflasked, the excess trimmed and polished the surfaces of the denture. Dentures processed with this procedure provides good retention and esthetic, more hygienic and comfortable for the patient than those processed with the conventional method. Giving more support and prevent teeth migration, comfortable for patient, good esthetic, give fine details of the mold and decreasing of time required for processing and finishing the cured prostheses.


Article
Porosity of different thickness of acrylic polymerized by different methods.

Author: Luay N Abood
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2007 Volume: 7 Issue: 2 Pages: 173-179
Publisher: Mosul University جامعة الموصل

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Abstract

Aims: To evaluate the porosity that occur in the acrylic resin denture base polymerized by themicrowave cycle and conventional water bath with two different thickness, relation between thethickness of specimen and its percentage of porosity. Material and methods: Forty rectangular resinspecimens with the following dimensions (65×40×6mm), (65×40×3mm) were subdivided according topolymerization method into microwave cycle and conventional heat polymerization method to obtain10 specimens with different polymerization method and thickness, for each one of 4 groups. Porositywas calculated by measure the specimen volume before and after its immersion in water, data wereanalyzed by student t–test analysis at ( p< 0.05). Results: Showed that specimens of (6mm) that curedby microwave polymerization method showed significantly higher percentage of porosity whencompared to the same thickness of conventional water bath polymerized acrylic resin at (p<0.05), whileno significant difference between the percentage porosity of the conventional and microwave heatcured acrylic resin of (3mm) thickness specimens. Also there is no significant difference between thethickness of specimen and the conventional water bath method of heat cured acrylic resin. While formicrowave curing method of heat cured acrylic resin there is significant difference for increase ofpercentage of porosity with increase of thickness of specimens. Conclusions: The conventional acrylicresin of (≥3mm) specimens thickness can be polymerized with microwave curing method safely withless porosity , while for (≥ 6mm) specimens thickness is preferred to be polymerized by conventionalwater bath curing method

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