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Article
A comparative study between the atomic absorption and spectrophotometric method in the assessment of the corrosion

Author: Suhad.J.Hemed
Journal: journal of kerbala university مجلة جامعة كربلاء ISSN: 18130410 Year: 2011 Volume: 9 Issue: 4 Pages: 21-25
Publisher: Kerbala University جامعة كربلاء

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Abstract

Back ground: Atomic absorption method is the most accurate method in the assessment for the determination of corrosion of dental alloy. The spectrophotometric method with the use of chromogenic complex was used also in the assessment of the corrosion. The aim of this study was to compare between the two methods.Material and Methods: twenty amalgam specimens were used: each was stored in 5 ml of normal saline solution for 1 month. The specimens were randomly grouped into two groups (group A and group B). Then the assessment of the corrosion was done by measuring of the released mercury, for group A is done by the atomic absorption method and for group B by the spectrophotometric method.Result: there is no statistical significant difference between two methods.Conclusion: the spectrophotometric method was successful alternative method to the atomic absorption methods in the assessment of the corrosion.

مقدمة :-تعتبر طريقة الامتصاص الذري الطيفي من أفضل الطرق وأدقها وأكثرها صحة في قياس مدى تآكل المعادن المستخدمة في طب الأسنان . قدمت الطريقة الطيفية مع استخدام مركبات معقدة ملونة وحساسة خاصة ايضا لقياس التاكل حيث انها طريقة اسرع واقل تعقيداَ . يهدف هذا البحث لاجراء مقارنة بين الطريقتين. المواد والطرق: اخذت عشرون عينة من كبسولات حشوات الاملغم ، وضعت بعد تحضيرها في 5مل من السائل الفسيولوجي الطبيعي وحفظت لمدة شهر في حاضنة بدرجة 37 درجة مئوية ، ثم قسمت عشوائيا الى قسمين : قسم أ وقسم ب تم قياس الزئبق المطروح في سائل الحفظ لعينات القسم أ بطريقة الامتصاص الذري اما القسم ب فقد تم القياس بطريقة الطيف مع المعقد الملون.النتيجة: لا فرق بين نتائج الطريقتين.الاستنتاج: طريقة القراءة الطيفية يمكن ان نعتبرها بديلا ناجحا لطريقة الامتصاص الذري في قراءة تآكل المعادن.


Article
Microleakage through cervically exposed dentinal tubules in root canal filled teeth pretreated with desensitizing agent

Author: Suhad J. Hemed سهاد حمد
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2005 Volume: 17 Issue: 3 Pages: 33-36
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: Dentin permeability and microleakage are related together and provide a continuous, microscopic, bidirectional fluid filled route between the oral cavity and the pulp space This study investigates the effect of pretreatment of inner canal wall with ferric-oxalate (desensitizing agent) on the salivary recontamination occurring between the root canal wall and sealer through cervically exposed dentinal tubules.Material and Methods: Forty extracted mandibular premolar teeth were chemomechaincally prepared then randomly divided into two main groups. The inner canal wall of each tooth in the second group was pretreated with ferric oxalate, and then all the teeth were obturated. A ring of 3 mm length at the cervical level of the teeth was subjected to root planning. All specimens were coated except for the ring area subjected to root planning, that was treated with citric acid. The specimens were exposed to natural saliva then pelikan ink. Then cleared and liner dye penetration was measured.Results: Linear dye penetration was measured and the results were statistically analyzed using T-test.Conclusion: The treatment of the inner canal wall with ferric-oxalate significantly reduced the microleakage through the cervically exposed dentinal tubules.


Article
The solubility of a zinc oxide eugenol root canal sealer (Endofil) in normal saline solution at different time intervals

Authors: Suhad J. Hemed سهاد حمد --- Waleed M. Khalil وليد خليل --- Saif Al Arab A. Mohammed سيف العرب محمد
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2005 Volume: 17 Issue: 3 Pages: 4-7
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: The solubility of the root canal sealers is undesirable, because the process of dissolution may result in gaps and voids along the sealer-dentine or sealer-gutta percha interface. The aim of this study was to assess the solubility of zinc oxide based sealer (Endofil) in normal saline solution at different time intervals.Materials and methods: Fifty standardized plastic ring moulds were constructed and filled with Endofil sealer. The specimens were allowed to dry for 24h then weighed to the nearest 0.0001g .The samples were divided randomly into 5 groups and immersed in normal saline solution for 1,7,14,28 and 56 days. The samples were removed from the solution after completing the specified immersion period and allowed to dry for 24h. Then they were weighed, the percentage weight loss was then determined.Results: The percentage weight loss was less that 3% for immersion periods not exceeding 14 days and increased up to 5.4% for the 56 days. The statistical analysis of the results revealed a non significant difference between 1 and 7 days immersion time groups, while the differences between other groups were statistically significant.Conclusion: Under the conditions of the present study, the Endofil sealer met the International Standard ISO requirement for at least 14 days. The solubility rate of the sealer increased gradually from the first day till the 56 th days, but it remained within the acceptable limits for only 14 days.

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