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Article
The effects of acetic acid and chlorhexidine gluconate as a cavity cleanser on the shear bond strength of compomer restorations

Author: Raghad A. Mohammed
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2008 Volume: 20 Issue: 2 Pages: 30-32
Publisher: Baghdad University جامعة بغداد

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Abstract

ABSTRACT
Background: Bonding of restorative materials to tooth structure has become one of the prime objectives of modern dentistry. The purpose of this in vitro study was to evaluate and compare the shear bond strength of compomer material to dentin washed with three cleanser agent.
Materials and Methods: Thirty freshly extracted adult human maxillary first premolars teeth were utilized in this study. Each tooth was sectioned horizontally exposing the dentin surface. According to the type of cleanser agent used to wash the dentin surface; the teeth were divided into three groups of ten teeth each: Group I chlorhexidine cleanser with compomer; Group II acetic acid with compomer; and Group III distal water with compomer. The measurement for evaluation the shear bond strength of compomer to dentin by using Zwick universal testing machine
Results: The results showed that higher significant different between group I and group III also between group II and group III; however< there is no significant difference between group I and group II.
Conclusions: This present in vitro study concludes that the shear bond strength of compomer material to dentin can be enhanced by washing the exposed dentin with cleanser agents’ chlorhexidine and acetic acid instead of distal water.
Keywords: Shear bond strength, cleanser, compomer. (J Bagh Coll Dentistry 2008; 20(2)30-32)

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Article
An evaluation the sealing ability of a three retro-filling materials

Author: Raghad A. Mohammed رغد محمد
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2005 Volume: 17 Issue: 2 Pages: 5-7
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: Retro end filling is important to establish a seal between the root canal space and the periapical tissue. The purpose of this in vitro study was to evaluate the quality of seals obtained with various retro-grade filling materials using dye penetration method of micro leakage measurement.Materials and methods: Forty extracted human single rooted teeth were used. Following root canal obturation, 30 teeth were divided into three experimental groups and each group was subjected to one of the three filling techniques: acold burnishing of gutta percha, bcalcium phosphate cement, csuper EBA cement. The remaining 10 teeth were considered as a control group. The teeth were placed in methylene blue dye for a period of 10 days after which they were washed, sectioned and the apical dye penetration measured.Results: The results showed that (CPC) and super EBA cement demonstrated less dye penetration than other experimental groups; the difference was statistically significant as compared with groups 1 & 4 and not significant as compared between groups 2&3.Conclusion: A general trend was observed that the apical leakage was found in all teeth but with different degrees, some leaked more than others, dye penetration was more with the cold burnished gutta percha


Article
Assessment of consistency and compressive strength of glass ionomer reinforced by different amount of hydroxyapatite

Authors: Raghad A. Mohammed --- Mohammed R. Al-jabouri
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2008 Volume: 20 Issue: 1 Pages: 16-20
Publisher: Baghdad University جامعة بغداد

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Abstract

ABSTRACT:
Background: Glass ionomers have good biocompatibility and the ability to adhere to both enamel and dentin. However, they have certain demerits, mainly low tensile and compressive strengths. Therefore, this study was done to assess consistency and compressive strength of glass ionomer reinforced by different amount of hydroxyapatite.
Materials and Methods: In this study hydroxyapatite materials were added to glass ionomer cement at different ratios, 10%, 15%, 20%, 25% and 30% (by weight). The standard consistency test described in America dental association (ADA) specification No. 8 was used, so that all new base materials could be conveniently mixed and the results would be of comparable value and the compressive strength test described by British standard specification for zinc polycarboxylate cement was used in this study.
Results: Different consistencies of materials produced a disc of varying sizes. The amount of the powder (in milligram)
was mixed with 0.5 ml of liquid to produce a consistency giving a disc of 3 cm±1mm in diameter were 500 mg for
glass monomer cement, 450 mg for glass ionomer cement reinforced by 10%, 5% and 30% of hydroxyapatite and
350 mg for glass ionomer cement reinforced by 20% and 25% of hydroxapatite. The results showed that the glass
ionomer cement reinforced by hydroxyapatite has higher compressive strength than conventional glass ionomer.
Conclusion: The addition of hydroxyapatite to conventional glass ionomer requires less powder to liquid ratio. Addition of hydroxyapatite to glass ionomer cement increased its compressive strength.
Key words: Consistency, compressive, Glass ionomer, Hydroxyapatite. (J Bagh Coll Dentistry 2008; 20(1) 16-20)

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Article
A comparative study of the sealing ability of two different obturation techniques with and without the use of sealers.

Authors: Raghad A. Mohammed --- Ahmed G. Subhy
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2008 Volume: 20 Issue: 1 Pages: 5-7
Publisher: Baghdad University جامعة بغداد

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Abstract

ABSTRACT
Background: The final stage of endodontic therapy is complete obturation of the root canal system to provide as perfect as possible at the cementodentinal junction of the apical foramen. The purpose of this in vitro study was to evaluate the sealing ability of injection molded thermoplasticized gutta percha and lateral condensation techniques with and without the use of sealers.
Materials and Methods: Forty freshly extracted adult human maxillary central incisors with complete formed apices were utilized in this study. The teeth were randomly divided into four groups for evaluation of the apical seal. Group (1) lateral condensation gutta percha technique without sealer, (2) lateral condensation gutta percha technique with sealer, (3) Injection molded thermo plasticized gutta percha without sealer, (4) injection molded thermoplasticized gutta percha with sealer. Groups 1 through 4 were obturated as specified. All of the teeth were immersed in flourescine dye for 48 hours, then they were removed from the dye for microleakage measurement.
Results: The results showed no significant differences between groups 1 and 3 and between groups 2 and 3 (p>0.05), but there were highly significant differences between groups 1 and 3 (p<0.01).
Conclusion: Sealer was found to be an essential part of the thermo plasticized gutta percha and lateral condensation techniques. Thermo plasticized system with sealer had significantly less apical leakage than others. The highest amount of leakage was significantly seen with lateral condensation without sealer.
Key words: Obturation techniques, sealer, microleakage. (J Bagh Coll Dentistry 2008; 20(1)5-7)

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Article
In vitro study to compare the sealing ability of a hydroxyapatite endodontic sealer with other Sealers (Quantitative Measurement)

Authors: Raghad A MOHAMMED --- Majidah K AL-HASHIMI
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2001 Volume: 1 Issue: 3 Pages: S247-S256
Publisher: Mosul University جامعة الموصل

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Abstract

This study is designed to compare and evaluate the sealing ability of a new Iraqi hydroxyapatite-containing endodontic sealer and other sealers using spectrophotometric system as a quantitative measurement of the volume of dye penetration into root canals. Fifty single-rooted extracted human teeth were used.Step-back technique was used to flare and enlarge the canals, the teeth were divided into five groups according to the type of sealer used: Group I:Zincoxideeugenol cement sealer, Group II: ZOE + hydroxyapatite (Iraqi), Group III: Glass ionomer cement sealer, Group IV: GIC + hydroxyapatite (Iraqi), Group V: Calcium phosphate cement + zincoxide(Wach's cement).All groups were immersed in methylene blue dye for one week then dissolved in 50% nitric acid and filtered then centrifuged. The leakage was assessed quantitatively using a spectrophotometric system. The results showed that calcium phosphate cement + zincoxide,(Wach's cement) had the lowest mean of dye leakage, followed by glass ionomercement sealer, then glass ionomer cement Sealer + hydroxyapatite, while ZOE had the highest mean of dye penetration into the filled root canal, The newly developed Iraqi hydroxyapatite containing endodontic sealer was as effective as the other tested sealers concerning apical microleakage.


Article
Assessment of diametral tensile strength and microhardness of Glass ionomer reinforced by different amounts of Hydroxyapatite

Authors: Mohammed Rasheed محمد رشيد --- Raghad A. Mohammed رغد محمد
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2006 Volume: 18 Issue: 3 Pages: 17-20
Publisher: Baghdad University جامعة بغداد

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Abstract

Back ground: Glass ionomer materials lack resistance to wear and pressure and are susceptible to moisture during the initial stages of setting and dehydration. So this study was done to assess diametral tensile strength and microhardness of glass ionomer reinforced by different amounts of hydroxyapatite.Materials and methods: In this study a hydroxyapatite material was added to glass monomer cement at different ratios: 10%, 15%, 20%, 25% and 30% (by weight). The diametral tensile strength test described by the British standard specification for zinc polycarboxylate cement was used in this study and the microhardness test was performed using Vickers microhardness testing machine and the microhardness values were calculated and statistical comparison was performed on the tested groups.Results: The group of glass ionomer cement that contains 20% hydroxyapatite has higher diametral tensile strength and microhardness values than other groups of this study. Also the results showed that the group of glass ionomer cement without hydroxyapatite has the lowest values of diametral tensile strength and microhardness than other groups. The groups of glass ionomer cement with 10%, 15%, 25% and 30% hydroxyapatites also showed increasing in diametral tensile strength and microhardness values in comparison with group of glass ionomer cement without hydroxyapatite.Conclusion: The addition of hydroxyapatite to conventional glass ionomer cement will increase its diametral tensile strengthand microhardness.


Article
The Effects of Acetic Acid and Chlorhexidine Gluconate as a Cavity Cleanser on the Shear Bond Strength of Compomer Restorations

Author: Dr. Raghad A. Mohammed.B.D.S, M.Sc.* د.رغد محمد
Journal: MUSTANSIRIA DENTAL JOURNAL مجلة المستنصرية لطب الاسنان ISSN: 18138500 Year: 2009 Volume: 6 Issue: 1 Pages: 28-31
Publisher: Al-Mustansyriah University الجامعة المستنصرية

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Abstract

Bonding of restorative materials to tooth structure has become one of the prime objectives of modern dentistry. The purpose of this in vitro study was to evaluate andcompare the shear bond strength of compomer material to dentin washed with three cleanser agent. Thirty freshly extracted adult human maxillary firs,, premolars teeth were utilized in this study. Each tooth was sectioned horizontally exposing the dentin surface. According to the type of cleanser agent used to wash the dentin surface; the teeth were divided into three groups often teeth each: Group I chlorhexidine cleanser with compomer; Group II acetic acid with compomer; and Group III distal water with compomer. The measurement for evaluation the shear bond strength of compomer to dentin by using Zwick universal testing machine. The results showed that higher significant different between group I and group III also between group II and group III; however< there is no significant difference between group I and group II. This present in vitro study concludes that the shear bond strength of compomer material to dentin can be enhanced by washing the exposed dentin with cleanser agents chlorhexidine and acetic acid instead of distal water.


Article
A comparative study to evaluate the sealing ability of a prisma dycal placed in cervical root perforation versus other materials (in vitro study)

Authors: Ahmed H. Ali احمد علي --- Raghad A. Mohammed رغد محمد --- Shatha Abdul- Kareem شذى عبد الكريم
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2005 Volume: 17 Issue: 3 Pages: 1-3
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: Calcium Hydroxide preparations are used extensively in dentistry, and one of these aspects is treatment of root perforations. The purpose of this in vitro study was to compare the sealing ability of a prisma (visible light cure dycal), amalgam with varnish and chemical cure dycal are used to repair lateral root perforations.Materials and Methods: Thirty extracted human maxillary anterior teeth were used; each tooth was sectioned longitudinally into facial and palatal halves .The perforations were made into each half tooth at the cervical third of the root. The samples were divided into three groups; group I was repaired with prisma, group II repaired with chemically cured dycal and group III with varnish and amalgam .The teeth halves were placed in methylene blue dye for one week period then linear dye penetration was measured from where the repair materials were made.Results: The results showed that a prisma (visible light cure dycal) demonstrated less dye penetration than other groups, the difference was statistically significant (p<0.01) from other groups, non significant differences (p>0.05) were present between amalgam with varnish and the chemically cured dycal.Conclusion: Calcium Hydroxide including the visible light cured and the chemically cured, and the amalgam with varnish, each possess a therapeutic potential for treating known and undetected root perforations. Percentage of leakage was more in amalgam with varnish group than prisma and Kerr Dycal


Article
Isolation and a Study of Acidic Deoxyribonuclease from Blood of Acute Myocardial Infarction Patients
عزل ودراسة إنزيم الديوكسي رايبونيوكليز الحامضي من دم المرضى المصابين باحتشاء العضلة القلبية الحاد

Authors: Raghad A. Mohammed رغد عبد الموجود محمد --- Layla A. Mustafa ليلى عبد الله مصطفى
Journal: Rafidain journal of science مجلة علوم الرافدين ISSN: 16089391 Year: 2010 Volume: 21 Issue: 3A Pages: 121-137
Publisher: Mosul University جامعة الموصل

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Abstract

The current research was concerned with a biochemical study of acidic deoxyribonuclease DNase II which was isolated from the serum of patients suffering acute myocardial infarction (AMI) as a marker for diagnosis of AMI. The results showed a significant increase in the activity of DNase II enzyme in the serum of the AMI patients with a mean value (268.0+ 6.90) U/L compared to the activity of healthy people (25.7+ 1.60) U/L. The enzyme was isolated from the blood of AMI patients using different biochemical techniques. Two proteinous components had been isolated by gel filtration technique from the precipitate produced by ammonium sulfate. It was found that only the first peak has DNase II activity. The apparent molecular weight of the enzyme using gel filtration was found to be (67000) Dalton. The research was also concerned with finding of optimum conditions for DNase II activity. Maximum activity was obtained using (32) g/ ml of deoxyribonucleic acid as a substrate for the enzyme, in acetate buffer at pH (4.50) and temperature of (40) 0C at a reaction time of (150) second. Using Line Weaver-Burk plot, it was found that maximum velocity Vmax and Michaelis Menten constant Km have the values of (120.5) U/ L and (1.8) g / ml respectively. Finally, the effect of some chemical compounds and nucleotides on the DNase II activity was also studied. It was found that EDTA showed a maximum inhibition with (100%) on the activity of the enzyme at a concentration of (5) mmol, while CuSO4 obtained maximum activation with (157.36%) on the activity of the enzyme at a concentration of (10) mmol in comparison to other chemical compounds, But. β-Mercaptoethanol, 5'-dGMP and 5'-dUMP showed activation effect on the activity of the enzyme at a concentration (0.1) mmol with (78.02%, 189% and 201%) respectively. It was found that Isordil showed a competitive inhibition on the activity of the enzyme at a concentration of (0.01) M.

تضمن البحث الحالي دراسة كيموحيوية لإنزيم الديوكسي رايبونيوكليز الحامضي DNase II الذي تم عزله من مصل دم الأشخاص المصابين باحتشاء العضلة القلبية الحاد. وأظهرت النتائج وجود زيادة معنوية في فعالية إنزيم DNase II في مصل دم الأشخاص المصابين إذ بلغ معدل الفعالية (268.0+6.90) وحدة/لتر مقارنة مع معدل الفعالية للأشخاص الأصحاء (25.70+1.60) وحدة/لتر، لذا يعد إنزيم DNase II كمؤشر للإصابة باحتشاء عضلة القلب الحاد. تم عزل إنزيم DNase II من مصل دم الأشخاص المصابين بالاحتشاء القلبي الحاد باستخدام التقنيات الحياتية المختلفة حيث تم فصل حزمتين بروتينيتين رئيستين من البروتينات بتقنية الترشيح الهلامي للراسب البروتيني الناتج من عملية الترسيب بكبريتات الامونيوم، وأظهرت واحدة منها فقط فعالية لإنزيم DNase II، وقدر وزنها الجزيئي التقريبي باستخدام تقنية الترشيح الهلامي وكان بحدود (67000) دالتون. وتضمن أيضاً إيجاد الظروف المثالية لفعالية إنزيم DNase II وكانت الفعالية القصوى كالآتي باستخدام (32) مايكروغرام/مليلتر من الحامض النووي الديوكسي رايبوزي DNA بوصفها مادة أساس للإنزيم، و (0.1) مولار من المحلول المنظم للخلات عند الأس الهيدروجيني (pH=4.5) وبدرجة حرارة (40) درجة مئوية وبزمن تفاعل (150) ثانية. تم إيجاد قيمة السرعة القصوى وثابت مكيلس-منتن باستخدام رسم لاين ويفر-برك وكانت مساوية لـ (125) وحدة/لتر و(1.8) مايكروغرام/مليلتر على التوالي. وأخيراً تمت دراسة تأثير بعض المركبات الكيميائية والنيوكليوتيدات على فعالية إنزيم الـ DNase II، وتبين أن استخدام الاثيلين ثنائي أمين رباعي حامض الخليك وبتركيز (5) ملي مولر أعطى تثبيطاً كلياً وبنسبة 100% لانزيم DNase II بينما استخدام كبريتات النحاس وبتركيز (10) ملي مولر أبدت أعلى تنشيط للانزيم وبنسبة 157.36% مقارنة بالمركبات الكيميائية الأخرى، أما بيتا-ميركابتوايثانول و 5َ-ديوكسي كوانوسين احادي الفوسفات (5'-dGMP) و5َ- ديوكسي يوريدين احادي الفوسفات (5'-dUMP) أظهرت تأثير تنشيطي للانزيم (78.02% و189% و201%) على التوالي، ووجد أن الايزورديل يعمل مثبطاً تنافسياً لفعالية الأنزيم عند تركيز (0.01) مولار.

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