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Article
Effects of composite thickness on shear bond strength to dentin

Authors: Sabah Abdul—Wahab Ismail BDS,M.Sc *. د.صباح عبد الوهاب --- Abdul-Haq Abdul-Majeed Suliman BDS,M.Sc.,Ph.D د. عبد الحق عبد المجيد
Journal: MUSTANSIRIA DENTAL JOURNAL مجلة المستنصرية لطب الاسنان ISSN: 18138500 Year: 2005 Volume: 2 Issue: 2 Pages: 150-156
Publisher: Al-Mustansyriah University الجامعة المستنصرية

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Abstract

Sixty non-carious extracted human molars were used in this study. The enamelon the occlusal surface ofthe crown of the tooth was removed by a diamond bur thenthe surfaces of the teeth were ground flat. The teeth were randomly divided into sixgroups each of ten and stored in distilled water at 370 C. Two types of composite wereused in this study, Definite and Tetric. The bonding agents Etch and Prime wereprepared according to manufacturers directions and applied to the dentin surface onthe first three groups and light cured for 20 seconds. The composite Definite waspacked into either 2, 3, and 4mm thick using split metal mould in the first, secondand third groups respectively and bulk-cured from top of the composite for 40seconds, the same procedure was repeated in the remaining three groups but thecomposite used was Tetric which its corssponding bonding agent was Excite. Thebond strength was measured with universal compression machine.The results showed `that there was no significant difference between the two types of composite Tetric andDefinite used in this study. The shear bond strength was affected by the compositethickness, the 2 mm increment showed higher bond strength than the 3mm and 4mmincrement in both composites


Article
Effect of Different Metal Bonding Agents on Shear Bond Strength of Ceramic to Direct Metal Laser Sintering

Author: Mustafa N. Abdulghani مصطفى نبيل عبد الغني
Journal: Tikrit Journal for Dental Sciences مجلة تكريت لعلوم طب الاسنان ISSN: 20731213 Year: 2017 Volume: 5 Issue: 1 Pages: 109-114
Publisher: Tikrit University جامعة تكريت

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Abstract

Introduction: laser sinter Cobalt Chromium metal replacing traditional castingprocesses of dental alloys for metal ceramic restorations, appropriate bonding ofceramic to metal is an important factor for long survival time. Twenty laser sintercubic metal 10 mm for each sides was fabricated by software designing andCADCAM direct metal laser sintering technique. The twenty cubics were classifiedaccording to the type of metal to ceramic bonding agents into two groups (n=10),Ceram bond apply for group A and Crea alloy bond for group B. Samples fabricatedusing custom made silicon index was used to act as standardized mold for metalbond application and porcelain buildup. Instron with chisel indenter and specialholding device were involve to measure the strength of bond for ceramic to lasersinter metal. The mean shear bond load of group A (688.8N) was significantlyhigher than that of group B (303.2N). Application of Ceram bond to metal lasersinter produces more bond strength when compare to usage of Crea bond material.

Keywords

Ceramic laser --- Bonding


Article
Impact of Sorts Disinfection and Cleansing Material on Hardness of Different Types of Denture Base Material

Author: Reem Ahmed Shihab ريم احمد شهاب
Journal: Tikrit Journal for Dental Sciences مجلة تكريت لعلوم طب الاسنان ISSN: 20731213 Year: 2017 Volume: 5 Issue: 1 Pages: 135-142
Publisher: Tikrit University جامعة تكريت

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Abstract

Dentist, dental technician and assistants are faced a several kinds of microorganisms during worklike bacteria, fungi and viruses .So, we can prevent cross contamination by using either chemicalor mechanical disinfection. The aim of the research was to measure the effect of different typesof chemical disinfection on the hardness of two types of denture base resin, heat activated acrylicand nylon (flexible). A total number of 80 denture resin specimens (40 specimens from heatactivated acrylic and 40 specimens from flexible resin) were prepared. Each type of specimenwas subdivided into 4 groups. Three groups were divided according to the type of denturedisinfectants (1%sodium hypochlorite, 1% povidine/iodine, Kin solution) and the fourth whichconsidered as control group was immersed in distilled water. All specimens were immersed intesting solution for 90 minutes at 370C. The hardness of the specimens before and afterimmersion was tested using Shore D machine. Our study showed that the mean value ofhardness test for poly methyl methacrylate higher than polyamide and there need aid nonsignificantContrast in the resistance of the surface to scratches and indentation between diversesorts of thermoplastic resin after using chemical disinfectant and denture cleansers withcomparison with control group for each type of denture base resin. The resistance to indentationof different types of denture base would not affected by short time immersion in chemical

Keywords

Ceramic laser --- Bonding.


Article
Evaluation the effect of eugenol containing temporary fillings on shear bond strength of composite restoration

Author: Dr. Farid G. Numan B.D.S., M.Sc د. فريد غياب
Journal: MUSTANSIRIA DENTAL JOURNAL مجلة المستنصرية لطب الاسنان ISSN: 18138500 Year: 2012 Volume: 9 Issue: 2 Pages: 159-163
Publisher: Al-Mustansyriah University الجامعة المستنصرية

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Abstract

The purpose of this in-vitro study was to evaluate the effect of eugenol-containingtemporary fillings on shear bond strength of composite to dentin and determine theefficiency of dual bonding technique in improving the bond strength using AdperSingle Bond 2 adhesive with 3M composite. Thirty sound human upper firstpremolars were used in this study. The occlusal surface of each tooth was ground toexpose superficial dentin layer, and then dentin bonding agent was directly appliedonto freshly prepared dentin together with cylinder of 3M composite and light cured(group I, control group). Dentin surface pre-treated with zinc oxide eugenol temporaryfilling, then dentin bonding agent together with a cylinder of 3M composite (group II,single bonding technique). While in group III dentin bonding agent was applied firston the dentin surface and light cured, then zinc oxide eugenol temporary filling wasadded for one week, after removal of temporary filling dentin bonding agent togetherwith 3M composite was applied and light cured (dual bonding technique). The shearbond strength of all the specimens was determined using Zwick universal testingmachine. The results showed that all temporary filling treated groups (II and III) hadlower mean shear bond strength compared to control group (group I), whereascompared to single bonding technique, dual bonding technique significantly increasedthe shear bond strength.


Article
Mesomorphic Properties of Symmetric Hydrogen – Bonding Dimers Containing Chalcone Moiety
صفات الاطوار الوسطية لدايمرات متماثلة ذات تاصر هيدروجيني و محتوية على مجموعة جالكون

Author: Ali kareem A. Al-Lami علي كريم اللامي
Journal: Iraqi Journal of Science المجلة العراقية للعلوم ISSN: 00672904/23121637 Year: 2014 Volume: 55 Issue: 4A Pages: 1455-1464
Publisher: Baghdad University جامعة بغداد

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Abstract

The work involves synthesis of a new homologous series of hydrogen bonding liquid crystal dimers containing chalcone moiety. All the prepared compounds were characterized by spectroscopic techniques such as FT – IR, 1H-NMR, 13C-NMR as well as elemental analysis. All the synthesized dimers exhibited nematic and smectic A phase. The mesophases behaviour and transitional temperatures were studied by polarized microscopy and differential scanning calorimetry, and are discussed the self- assemble of H-bonding donor and acceptor complexes.

تضمن العمل تحضير سلسلة جديدة من الدايمرات البلورية السائلة ذات التاصر الهيدروجيني والمحتوية على المجموعة الجالكونية. شخصت جميع المركبات المحضرة بالتقنيات الطيفية مثل مطيافية الاشعة تحت الحمراء ومطيافية الرنين النووي المغناطيسي بالاضافة الى تحليل العناصر الدقيق. اظهرت الدايمرات المحضرة الاطوار الوسطية النيماتية والسمكتية. درست خصائص الاطوار الوسطية ودرجات الانتقال بجهازالمكروسكوب المستقطب وجهاز المسح الحراري التفاضلي وتمت مناقشة تكوين الاواصر الهيدروجينية بين المعقدات الواهبة و المستقبلة.

Keywords

hydrogen bonding --- complex --- nematic --- chalcone


Article
Coronal microleakage of root canal filled teeth pretreated with ferrie-oxalate or dental bonding agent

Authors: Suhad J AL-SHEMMARY --- Majidah K AL-HASHIMI
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2001 Volume: 1 Issue: 2 Pages: 160-165
Publisher: Mosul University جامعة الموصل

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Abstract

An In vitro study was carried out to compare the effects of the Smear layer and the pretreatment of the foot canal wall with tubular occluding desensitizing agent (6% ferric-oxalate) or a bonding agent on the coronal seal of endodontically treated teeth.Seventy freshly extracted human teeth with single and straight canals were used in This study. The teeth were divided into five experimental groups: twelve teeth each, withone positive and one negative control for each. Group I: With intact smear layer, Group II: Without smear layer. Group III: With intact smear layer and with ferric-oxalate painting of the canal walls. Group IV: Without smear layer and with ferric-oxalate painting of the canal walls. Group V: Without smear layer and with bonding agent.After canal obturation the access cavities were exposed to natural saliva then Pelikan ink. Teeth were cleared and linear dye penetration measured. The results showed that the removal of the smear layer significantly increased the tightness of the coronal seal, and pretreatment of the canal walls with ferric-oxalate significantly decreased the coronal microleakage more than with or without smear layer. Using the bonding agent with a hydrophilic primer, after removing the smear layer, showed significantly less microleakage than all other groups.


Article
The shear bond strength of moisture insensitive orthodontic bonding.

Author: Ne’am R. Al–Saleem
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2007 Volume: 7 Issue: 1 Pages: 61-65
Publisher: Mosul University جامعة الموصل

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Abstract

Aims: To assess the effect of water contamination on the shear bond strength of moisture insensitive Fuji Lc. glass ionomer and to compare it with the shear bond strength of (transbond) light cure composite. Materials and methods: Sixty extracted human premolar were cleaned and dried and embedded in cylinders filled with dental stone and the teeth were divided into three groups (20 teeth of each) which were etched and washed and dried the teeth in group 3 were slightly moistened in a cotton pellet and then the brackets were bonded to the teeth according to the manufacture instructions. Group1: using light cure composite (transbond); Group2: using glass ionomer cement (Fuji Lc.) in dry condition; Group3: using glass ionomer cement (Fuji Lc.) in moist condition. The shear bond strength was measured using instron mechanical test machine. Statistical analysis including descriptive statistics were applied to the results and then the findings were compared among the three groups using ANOVA and Duncan tests. Results: Light cure composite (transbond) had the highest shear bond strength followed by Fuji Ortho. Lc. (moist condition) and then Fuji Lc. (dry condition), which had the significant lowest shearbond strength. Conclusions: Transbond light cure composite had the highest shear bond strength. The presence of moisture enhances the shear bond strength of light cure glass ionomer cement (Fuji Lc.).


Article
Study of Microstructure and Some Mechanical Properties of Ceramic Matrix Composite Material
دراسة التركيب المجهري وبعض الخواص الميكانيكية للمواد المتراكبة ذات اساس السيراميكي

Author: Salim Aziz Kako سالم عزيز كاكو
Journal: AL Rafdain Engineering Journal مجلة هندسة الرافدين ISSN: 18130526 Year: 2007 Volume: 15 Issue: 3 Pages: 9-20
Publisher: Mosul University جامعة الموصل

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Abstract

Abstract The aim of this research is to study microstructure and some mechanical properties of ceramic matrix composite material. Powder of Al2O3 was used as ceramic material after had been pressed by different pressures (58 Mpa, 117 Mpa and 176 Mpa) in metallic mold. The sintering process has been preformed at 1200oC for two hours. After that, the porosity percentage has been measured and the samples were heated to 700oC and then immersed in the molten pure aluminum and (Al-2.26% Mg), and heated to about 1000oC for half an hour. Then, the samples were cooled to 650oC. Microscopic tests and x-ray diffraction analysis has revealed zones with different hardness and with different structures. Moreover, the results showed that the adhesion between the ceramic matrix and the deposited metal depends on the molten metal type and the percentage of magnesium content of aluminum. Keywords: Composites, Ceramic-metal bonding, Infiltration

الخلاصةيهدف البحث الحالي إلى دراسة التركيب المجهري وبعض الخواص الميكانيكية للمواد المتراكبة ذات الاساس السيراميكي. تم استخدام مسحوق الألومينا كمادة سيراميكية حيث تم كبسها تحت ضغوط كبس مختلفة (MPa 58 ، MPa 117 و MPa 176) في قالب معدني، ثم اجريت عليه عملية التلبيد عند (1200oC) ولمدة ساعتين وبعد حساب نسبة المسامية للنماذج السيراميكية الملبدة تم تسخينها الى(700oC) و من ثم غمرها بمنصهر المنيوم النقى ومنصهرسبيكة المنيوم-2.26% مغنيسيوم وبعد ذلك تم التسخين داخل الفرن إلى درجة حرارة (1000oC) ولمدة نصف ساعة، ومن ثم تم تبريد المنصهر إلى درجة حرارة (650oC).اظهرت نتائج الفحوصات المجهرية والفحص بحيود الاشعة السينية وجود مناطق مختلفة الصلادة وذات تراكيب والاطوار مختلفة هى المحلول الصلب وطور سبنل ، كما لوحظ من النتائج أن قوة الربط ما بين الاساس الالومينا السيراميكي و المنيوم النقى اومنصهرالمنيوم-2.26% مغنيسيوم المترسب يعتمد على نوع المنصهر المعدني ونسبة المغنسيوم فيه.


Article
The Effect of Various Bur Types, Bond-ing Agents, and Composite Types on The Microleakage of Resin Composites

Author: Raghad A Al-Askry
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2010 Volume: 10 Issue: 1 Pages: 176-185
Publisher: Mosul University جامعة الموصل

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Abstract

Aims: This in vitro study was conducted to investigate the effect of various bur types, bonding agents, and resin composite restorative materials on the microleakage at occlusal and gingival tooth/composite interfaces. Materials and methods: One hundred and sixty non carious, extracted human premolars were mounted in acrylic resin, the teeth were randomly divided into four groups (n=40) according to the bur types (diamond round bur, diamond fissure bur, carbide round bur, and carbide fissure bur). A standardize class V (3×2×2) mm dimensions cavity was prepared on the facial surface of each tooth (each group with corresponding bur type), then each group was divided into two subgroups (n=20) ac-cording to the type of adhesive systems used (P&B NT,& I-Bond), after that each subgroup farther divided in to two subgroups (n=10) according to the type of composite restorative materials (Arabesk & Tg) the final number of groups were (16) of (10) teeth in each. After the specimens were finished they stored for one month in 37ºc distilled water, thermo cycled for 500 cycles between (5ºc & 55ºc) and immersed in 0.5% methylene blue solution for 24h., and then sectioned longitudinally. For both occlusal and gingival margins, dye penetration at the tooth/composite interfaces were scored from 0-3 under stereomicroscope at a magnification x10, data were analyzed using unpaired T-test, ANOVA, and Duncan’s multiple rang test at 5% significant level. Results: T-test represent that there was less microleakage at occlusal margins than the gingival margins. ANOVA and Duncan’s multiple rang tests show that the less leakage was occurred with the use of carbide fissure bur at both occlusal and gingiv-al margins while the diamond round bur show the highest leakage at both margins. P&B NT show less leakage than I-Bond at the occlusal margin but there was no significant difference between P&B NT & I-Bond at the gingival margins also there was no significant difference between the ( Arabesk & Tg ) restorations at both occlusal and gingival margins. Conclusions: Within the limitations of this study results show that there was less microleakage at the occlusal margin than that at the gingival margins, and the use of carbide fissure bur to prepare the cavities for receiving resin composite materials show the least microleakage than other type of burs, and although phosphoric acid has been intensely used to etch the dental substrates (enamel and dentin) for providing a good bonding, self-etching adhesives can be considered an alternative methods to provided a good bonding for restorative procedures


Article
The effect of storage on shear bond strength of three composite resins to dentin

Author: Sabah A Ismail
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2005 Volume: 5 Issue: 1 Pages: 75-82
Publisher: Mosul University جامعة الموصل

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Abstract

The aim of this study was to determine the effect of storagetime on shear bond strength of three composite resin, twoutilize total etch technique and one utilize self etching bondingagent.One hundred twenty maxillary and mandibular molarswere used in this study. The teeth were prepared by cutting theocclusal enamel with diamond bur to expose dentin and groundwet with silicone carbide papers. The specimens were thendivided into three groups and stored in distilled water.Scotchbond Multipurpose Plus was used in the first groupand a stainless steel round mould, with a central hole of 4mm in diameter and 2 mm in height was used to build up thecomposite Z100. The composite resin was inserted in two increments,each one was light cured for 40 seconds. This gro-upis divided into four subgroups each of ten according to thestorage time (one day, fifteen days, three months and six months)then stored in distilled water accordingly.The same procedure was repeated in the second and thirdgroups. The composite used in the second group was Tetricwith Excite bonding agent. In the third group, Definite compositeand its bonding agent Etch and Prime was used.The bond strength was measured and the data were statisticallyanalyzed. Z100 composite had the greatest shear bondstrength followed by Tetric and Definite. One day and fifteendays storage time for all types of composite had greater shearbond strength than the three months and six months storagetime.In conclusion there was a gradual decrease in bond strengthwith increased storage time up to six months irrespectiveof the type of composite.

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