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Article
The effect of smear layer on push-out bond strength to dentin of Bioceramic sealer (In vitro study)

Authors: Hamid Abbas Hamid --- Abdul-kareem Jassim Al-Azzawi
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2013 Volume: 25 Issue: 4 Pages: 5-11
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: Sealers should demonstrate adhesive properties to dentin, decreasing the chance of endodontictreatment failure. Increased adhesive properties to dentin may lead to greater strength of the restored tooth, whichmay provide greater resistance to tooth fracture and clinical longevity of an endodontically treated tooth. The aimof this study was to evaluate the shear bond strength of Bioceramic iRoot SP sealer, AH plus sealer and Apexit plussealer in absence or presence of smear layer using push out bond strength test.Materials and Methods: Sixty straight single roots of the mandibular premolars were selected for this study. All canalswere instrumented using ProTaper rotary instruments to achieve tapered canal walls, instrumentation was done withcopious irrigation of 5.25% sodium hypochlorite. Roots were randomly divided into three groups according to thetype of sealer used (twenty teeth for each group): Group A: Apexit plus + gutta percha, Group B: AH plus sealer +gutta percha, Group C: iRoot SP sealer + gutta percha .Then groups were subdivided according to types of finalirrigation into two subgroups. Groups (A1, B1, and C1) were irrigated with 5 ml of 5.25% NaOCl for 1 minute whileGroups (A2, B2, and C2), the smear layer was removed with 5 ml of 17% EDTA for 1 minute. All groups were rinsed withdistilled water and then obturated with cold lateral condensation technique, the roots then stored in moistenvironment at 37°C for one week. The roots were embedded in clear acrylic resin and three horizontal sectionswere prepared at a thickness of 1 mm ±0.1 in the apical, middle and coronal parts of each root. The test specimenswere subjected to the push-out test method using a Universal Test Machine that carried 1-mm, 0.5- mm and 0.3-mmplungers for coronal, middle and apical specimens, respectively. The loading speed was 0.5 mm/ min. The computershowed the higher bond force before dislodgment of the filling material. These forces were divided by the surfacearea to obtain the bond strength in MPa.Results: The results showed that the bond strengths of iRoot SP and AH Plus were significantly higher than those ofApexit plus, but there was no significant difference between the bond strength of iRoot SP and AH Plus.In terms ofroot segments, the bond strengths in the middle specimens and the apical specimens were higher compared withthe bond strengths in the coronal specimens.Conclusion: The presence or absence of smear layer did not significantly affect the bond strength of Bioceramicfilling materials


Article
The effect of waterlase laser and herbal alternative, green tea and Salvadora Persica (Siwak) extract on push-out bond strength

Author: Abdul-kareem Jassim Al-Azzawi عبد الكريم جاسم العزاوي
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2014 Volume: 26 Issue: 2 Pages: 1-6
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: The bond strength of root canal sealers to dentin was important for maintaining the integrity of the sealin root canal filling in both static and dynamic situations. In a static situation, it should eliminate any space thatallowed the percolation of fluids between the filling and the wall while in a dynamic situation; it was needed to resistdislodgement of the filling during subsequent manipulation.Materials and Methods: Forty mandibular premolars were selected for this study. All canals were instrumented usingProTaper rotary instruments. Instrumentation was done with copious irrigation of 5.25% sodium hypochlorite. Rootswere randomly divided into four groups according to the type of cleaning and method of root canal irrigation (tenteeth for each group): Group A. The root canals were irrigated with 5 ml of 17% of EDTA for 1 minute and 5 ml of5.25% NaOCl. Group B. Cleaning with waterlase laser. Group C. The root canals were irrigated with 5 ml of 5mg/ml ofsiwak (Salvadora persica) extract for one minute. Group D. The root canals were irrigated with 5 ml of 5% of greentea (camellia sinensis) extract for one minute. All groups were rinsed with distilled water and then obturated with coldlateral condensation technique and i Root sp sealer (Bioceramic sealer, the roots then stored in moist environment at37°C for one week. Three horizontal sections were prepared at a thickness of 1 mm ±0.1 in the apical, middle andcoronal parts of each root. The test specimens were subjected to the push-out test method using a Universal TestMachine that carried 1-mm, 0.5- mm and 0.3-mm plungers for coronal, middle and apical specimens, respectively.The loading speed was 0.5 mm/ min. The computer showed the higher bond force before dislodgment of the fillingmaterial. These forces were divided by the surface area to obtain the bond strength in MPa.Results: In all groups the mean value of push-out strength was greatest in apical area and least in coronal area andthe middle area was in between, except in Waterlase the middle area showed the least mean push-out strength.Conclusion: Herbal extracts used in this study (Siwak and green tea) can be used safely as an intra-canal irrigant forsmear layer removal with efficiency that is comparable with conventional synthetic materials (EDTA) and morecomplicated methods (Waterlase).

Keywords

Waterlase --- Siwak --- Green tea --- push out test


Article
Push-out bond strength of different root canal obturation materials

Authors: Sundus H. Naser سندس ناصر --- Iman M. Al-Zaka
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2013 Volume: 25 Issue: 1 Pages: 14-20
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: The aim of this study was to evaluate the push-out bond strength of four different obturation materialsto intraradicular dentin and to determine the failure mode.Materials and method: forty straight palatal roots of the maxillary first molars teeth were used in this study, the rootswere instrumented using crown down technique and rotary EndoSequence system, the roots were randomly dividedinto four groups according to the materials used for obturation (n=10).Group (1): AH Plus sealer and gutta-percha.Group (2): Activ GP glass ionomer sealer and Activ GP gutta-percha (Activ GP system). Group (3): Bioceramic sealerand Bioceramic gutta-percha. Group (4): GuttaFlow2 sealer and gutta-percha. For all groups single cone obturationtechnique was used. After incubation period of one week, the roots were embedded in clear acrylic resin and eachroot sectioned into three levels apical, middle and cervical. The bond strength was measured using computerizeduniversal testing machine, each section fixed in the machine so that the load applied from apical to coronaldirection at 0.5mm/min speed and the computer drew curve to show the higher bond force before dislodgment ofthe filling material. After de-bonding each sample was examined under Stereomicroscopic and the type of failuremode was recorded.Results: showed a non significant difference between AH plus group and Bioceramic group. AH Plus group showed avery highly significant difference with Activ GP group and a highly significant difference with GuttaFlow2 group.There were significant differences between coronal level and both apical and middle levels with no significantdifferences between apical and middle levels within each group.Conclusion: AH plus group showed the highest mean of bond strength in comparing to other tested groups


Article
In Vitro Comparative Assessment Of The Effect Of Gutta-Fusion Obturation On The Push Out Bond Strenght Of Three Types Of Sealers

Authors: Ahmed A. Al-Qazwini احمد القزويني --- Raghad Al-Hashimi رغد الهاشمي
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2017 Volume: 29 Issue: 4 Pages: 13-19
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: The bond strength of the root canal sealers to dentin is very important property for maintaining the integrity and the seal of root canal filling. The aim of this study was to evaluate and compare the push-out bond strength of root filled with total fill Bioceramic, AH Plus and Gutta-flow®2 sealers using GuttaFusion®obturation system versus single cone obturation technique.Materials and method: sixty of mandibular premolars teeth with straight roots were used in this study, these roots were instrumented using Reciproc system, instrumentation were done with copious irrigation of 3 mL 5.25% sodium hypochlorite solution (NaOCl) during all the steps of preparation, and smear layer will be removed with 1 ml of 17% EDTA kept in the canal for 1 min, roots were randomly divided into two groups according to the obturation technique (thirty teeth for each group):Group I: Single Reciproc Gutta percha cone obturation technique, Group II: Gutta fusion obturation technique, then each group divided into three subgroup according to the type of sealer, AH subgroup: AH Plus sealer, BC subgroup: bioceramic sealer and GF subgroup: Gutta flow 2 sealer. The roots then stored in moist environment at 37°C for one week, the roots were embedded in clear acrylic resin and each root sectioned into three levels apical, middle and cervical. The bond strength was measured using computerized universal testing machine each section fixed in the machine so that the load applied from apical to cervical direction at 0.5mm/min. speed and the computer show the higher bond force before dislodgment of the filling material. These forces were divided by the surface area to obtain the bond strength in MPa.Results: Statistical analysis was performed and the result showed a highly significant differences between the three types of sealers when the same obturation technique were used, also there is highly significant differences between two groups with two different obturation technique.Conclusion: This study showed that the push out bond strength of AH plus sealer was higher than bioceramic sealer and Gutta flow 2 sealer respectively when the same obturation technique was used. The push out bond strength was affected by the obturation technique and Gutta fusion obturation technique showed higher bond strength than single cone obturation technique when the same type of sealer was used


Article
Comparison of regional bond strength of post space of fiber-reinforced post luted with two types of cements at different testing times

Authors: Haitham J. Al-Azzawi --- M.N.H.
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2013 Volume: 25 Issue: 3 Pages: 19-23
Publisher: Baghdad University جامعة بغداد

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Abstract

Back ground: This in vitro study was carried out to investigate the effect of post space regions (coronal, middle andapical), Time and the mode of polymerization (dual, self-cured) of the cements used on the bond strength betweentranslucent fiber post and root dentin by using push-out test.Materials and Methods: Forty eight extracted mandibular first premolars (single root) were instrumented with ProTaperUniversal system files (for hand use) and obturated with gutta percha for ProTaper and AH26® root canal sealerfollowing the manufacturer instructions, after 24 hours post space was prepared using FRC postec® plus drills no.3creating 8 mm depth post space. The prepared samples were randomly divided into two main groups (24 sampleseach) according to the used cement (Group M, self-cure, Multilink N) and (Group R, dual cure, Relyx U100). Theneach group was subdivided into three groups (each group contains 8 samples) according to the testing time aftercementation. (g M1: push out test after 24 hour of cementation with Multilink N), (g M2: push out test after one weekof cementation with Multilink N),(g M3: push out test after two weeks of cementation with Multilink N), (g R1: push outtest after 24 hours of cementation with RelyxU100), (g R2: push-out test after one week of cementation withRelyxU100), (g R3: push out test after two weeks of cementation with RelyxU100). After cementation and incubationeach root was sectioned horizontally into 3 slices (2 mm in thickness) represent the coronal, middle and apicalregions of the post space. Push out bond strength test was performed and measured using a universal testingmachine (Tinius-Olsen) at across head speed of 0.5 mm/min.Results: showed that regarding the root region, the bond strength values increased significantly apical to coronalregion in both tested cements. For the effect of time, the bond strength values also significantly increased with timefor both tested cements. For mode of polymerization, the self-cured resin cement Multilink N showed higher bondstrength values.Conclusion: the retention of fiber post was affected by root region, mode of polymerization of the cements usedand time elapsed after cementation of the post


Article
Monotonic and Fatigue Performance of Double-skin Push-out and Tensile Segments of Divers Shear Connectors – Review
ألأداء الراتب وأداء الكَلال لقِطَع الدفع الخارجي وقِطعَ الشد ثنائية القشرة بأنواع متباينة من روابط القص – ورقة عرض

Authors: Zainab H. AL-Zehhawi --- Laith Khalid AL-Hadithy
Journal: AL-NAHRAIN JOURNAL FOR ENGINEERING SCIENCES مجلة النهرين للعلوم الهندسية ISSN: 25219154 / eISSN 25219162 Year: 2019 Volume: 22 Issue: 3 Pages: 213-221
Publisher: Al-Nahrain University جامعة النهرين

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Abstract

Double skin composite (DSC) construction or Steel/concrete/steel sandwich construction (SCSS) is an innovative and relatively new form of composite construction that can be used in submerged tube tunnels, bridges deck, nuclear structures, liquid and gas containment structures, offshore and onshore structures, military shelters, and shear walls in buildings. The system consists of a plain concrete core sandwiched between two steel plates interconnected together by various types of mechanical shear connectors. The DSC construction perceives advantages that the external steel plates act as both formwork and primary reinforcement, and also as impermeable, blast and impact resistant membranes. The major duty of the shear connectors is to withstand longitudinal shear force and beam/slab separation, while in the bi-steel type where shear connectors are friction welded at both their two ends to two parallel steel plates, the longitudinal and transverse shear force, as well as plate buckling are resisted. The present paper highlights the previous prime researches concerning the subjects of SCSS composite construction, specifically on the conducted tests (push-out tests, tensile, direct shear tests, and bending tests) in which the components of partial interaction (uplift and slip forces) are resisted by various types of shear connectors.

تعتبر المشيًدات المركّبة ثنائية القشرة DSC أو المشيدّات السندويجيّة فولاذ - خرسانة - فولاذ SCSS أحد الأنواع المبتكرة والتشكيلات المعاصرة للمشيّدات المركبة المرَشًحة للإستخدام في الأنفاق الأنبوبية، أرضيات الجسور، ألمنشآت النووية، ألمنشآت الحاوية للسوائل أو الغازات، ألمنشآت المائيّة المحاذية للسواحل، ألملاجئ الحربية، والجدران المقاومة للقص في المباني العالية. تتكون تلك المنظومة الإنشائية من لُباب خرسانية صمّاء محشوًة بين صفيحتين فولاذيتين مرتبطتين معاً ارتباطاً داخلياً بوساطة روابط قص ميكانيكة متعددة الانواع. تحقِق تلك المنظومة الإنشائية المركبة مزايا إستثنائية اهمها قيام الصفيحتين الفولاذيتين الخارحيتين بوظيفتين اساسيتين احدهما انشائية وهي التسليح الرئيس والاخرى تشييديّة وهي قالبٌ دائم، علاوةً على قيامها بدَورالحاجز الأصّم المقاوم للعصف غير المباشر وللصدمات المباشرة. أمّا بخصوص روابط القصّ- في هذه المنظومة ألإنشائية المركبة ثنائية الطبقات الفولاذية - فإنّها تكون ملحومة الطرفين في كلتا الصفيحتين الفولاذيتين القشريتين لذا فإنّها - إضافة الى قيامها بالوضيفتين الرئيستين لروابط القص التقليدية وهما مقاومة قوى القص الطولية ومقاومة الانفصال العممودي على امتداد الاسطح البينيّة بين الفولاذ والخرسانة- فإنّها تقوم أيضاً بمقاومة قوى القصّ المستعرضة عل ألاسطح البينيّة واسناد الصفيحتين الفولاذيتين من الإنبعاج. تقوم المقالة العلمية الحالية بتسليط الاضواء على الابحاث الرئيسة المعاصرة في مجال سلوك المنظومات الانشائية السندويجية فولاذ - خرسانة - فولاذ مع الاهتمام الخاص بالفحوصات الرئيسة لها (فحوص ألشد، القص المباشر، والدفع الخارجي) حيث يتم فيها مقاومة مركبتي القوى على الاسطح البينية جزيئية الترابط (الانزلاق والانفصال) بوساطة اصناف متنوعة من روابط القص.


Article
Load-Slip Relationship in Modified Push-Out Test (Experimental Work)
علاقة القوة-الانزلاق في فحص الدفع المعدل (دراسة عملية)

Author: Mukhallad A. Z. Al-Sa’ady
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2007 Volume: 25 Issue: 3 Pages: 358-369
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

In this work, a modified push-out test is proposed to study the load-sliprelationship in steel-concrete-steel sandwich beams. This relation is one of themost important factors that are required in the analysis and design of steelconcrete-steel sandwich beams with partial interaction. The diameter of theconnector is assumed to be variable while the other parameters are keptconstants. The modification in this test in comparison with the standard testconcentrated on the use of steel tube- concrete slab- steel tube instead of concreteslab- steel (I-Section)- concrete slab (in Standard Test) in order to be morecompatible than the standard test in modelling the steel-concrete-steel sandwichor double-skin beams. The stud is suggested to be threaded along the wholelength, connected to the tube by a nut (the separation between the layers iseliminated and only interlayer slip is assumed to exist) and the connector passesto the other tube through the concrete slab (thus the connector is subjected todouble shear force). These cases maximize the function of this stud. Five dialgages are used; one at the base, and two at each side in order to measure the slipat each stud. An experimental relationship of load-slip is carried out to simulatethe behaviour of this type of connection in steel-concrete-steel sandwichconstruction.

في هذا البحث،تم اقتراح طريقه معدله لفحص الدفع لدراسة علاقة القوة-الانزلاق في العتبةالسندويجية حديد-كونكريت-حديد. هذه العلاقة هي واحدة من اهم العوامل المطلوبة في تحليلوتصميم العتبة السندويجية حديد-كونكريت-حديد ذات الترابط الجزئي. قطر الرابط فرض ليكونمتغيرا بينما العوامل الاخرى بقيت ثوابت. التعديل في هذا الفحص بالمقارنة مع الفحص القياسي تركز على استعمال تجميع من أنبوب مربع حديدي-شريحة كونكريتية-أنبوب مربع حديدي بدلا منشريحة كونكريتية(في الفحص القياسي) لكي يكون أكثر ملائمة -(I- شريحة كونكريتية-حديد(مقطعمن الفحص القياسي في نمذجة العتبة السندويجية حديد-كونكريت-حديد أو العتبة مزدوجةالصفيحة. الرابط أقترح أن يكون مسننا في الطول كله، ومربوطا الى الانبوب بواسطة الصامولة(الانفصال بين الطبقات ألغي وبقي فقط الزحف بين الطبقات) ويمر الرابط الى النبوب الاخر منخلال شريحة الكونكريت(بذلك يكون الرابط متعرضا الى قوة قص مزدوجة). هذه الحالات تزيد منوظيفة الرابط. خمسة مقاييس وضعت ، واحد في القاعدة، وأثنان في كل جهه من أجل قياسالزحف في موقع الرابط. تم أستخراج علاقة عملية تربط القوة مع الانزلاق لنمذجة سلوك هذا النوعمن الروابط في منشأت حديد-كونكريت-حديد السندويجية

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