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Article
The effect of addition of calcium hypochlorite disinfectant on some physical and mechanical properties of dental stone

Authors: Shorouq M. Abass شروق عباس --- Ibrahim K. Ibrahim
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2012 Volume: 24 Issue: special issue 1 Pages: 36-43
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: The potentially damaging effects of the immersion technique, the difficulty in covering the entiresurface of the cast with the spray disinfecting solution, and the inability to assume that every impression presented tothe laboratory has been disinfected has led to the need for incorporating a disinfectant directly into the calciumsulfate hemihydrate. This study was designed to evaluate the effect of the addition of Calcium Hypochoritedisinfectant on some physical and mechanical properties of the dental stone.Materials and methods: Calcium Hypochlorite disinfectant in aqueous solution in different concentrations 0.5, 1.0, 1.5and 2.0% was added to type III dental stone. Setting time, setting expansion, reproduction of details, compatibilitywith impression materials and consistency are physical properties which were evaluated. The compressive strengthand surface hardness as mechanical properties were also determined.Results: The results of this study showed that the addition of 1 % of calcium hypochlorite improved some of thephysical and mechanical properties of dental stone (Setting Expansion, Compressive Strength and Surface Hardness)while its adversely affected the other properties (Setting Time)Conclusions: The 1 % of calcium hypochlorite disinfectant solution could be used to disinfect dental cast with theleast effect when compared with the other concentrations of calcium hypochlorite


Article
Radiographic follow up for clinical cases of mandibular implant retained overdenture MIR-OD

Authors: Raghdaa K. Jassim رغداء جاسم --- Ibrahim K. Ibrahim
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2014 Volume: 26 Issue: 2 Pages: 7-11
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: The use of osseointegrated fixtures in dentistry has been demonstrated both histologically and clinicallyto be beneficial in providing long term oral rehabilitation in completely edentulous individual. Most patients sufferfrom denture instability; particularly with mandibular prosthesis, the use of dental implant will be benefit significantlyfrom even a slight increase in retention. The concept of implanting two to four fixtures in a bony ridge to retain acomplete denture prosthesis appealing therefore, as retention, stability and acceptable economic compromise tothe expanse incurred with the multiple fixture supported fixed prosthesis .Materials and methods in this study the sample were eight patients selected from a hospital of specialized surgery,these patient were wearing a mandibular implant retained over denture for two years these patients having MIR-ODwith Bar-clip, ball-cup and O- ring attachments. Preparative radiography was obtained for this patient from thecenter .these radiograph was taken to the patient at time of insertion. The second radiograph image was taken tothe patient after two years of function with prosthesis. .the scanned images were transfer to special folder in acomputer then analysis of bone loss done using Dimax software. After that an accurate calibrations of crestal bonemeasurement were analyzed for both groups of Radiography .Results it was appeared that the amount of bone loss in ball and bar designs (of mandibular Implant retainedoverdenture) were within the criteria of successful rate of bone loss during the period of examination, and there wasstatistically significant difference between both types of anchorage system.Conclusions The amount of bone loss was 0.1 mm after two years follow up, and it was within the acceptable limits ofbone lose. A significant difference appeared between both designs of MIR-OD, Ball and bar designs

Keywords

Radiograph --- implant --- overdenture --- Dimax


Article
Finite element stress analysis study for stresses around mandibular implant retained overdenture MIR-OD

Authors: Raghdaa K. Jassim رغداء جاسم --- Ibrahim K. Ibrahim
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2014 Volume: 26 Issue: 2 Pages: 30-36
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: It has been well known that the success of mandibular implant- retained overdenture heavily dependson initial stability, retention and long term osseointegration this is might be due to optimal stresses distribution insurrounding bones. Types of mandibular implant- retained overdenture anchorage system and number of dentalimplants play an important role in stresses distribution at the implant-bone interface. It is necessary to keep thestresses below the physiologic tolerance level of the bone .since. And it is difficult to measure these stresses aroundbone in vivo. In the present study, finite element analysis used to study the stresses distribution around dental implantsupporting Mandible implant retained overdentureMaterials and methods: Eight models were constructed including four designs of anchorage system (ball-cup, ball-ORing, bar without distal extension and bar with distal extension).The first group of models were supported by fourdental implant and second group of models were supported by two dental implant only. Models constructed fromthe data obtained directly from patient The contour of bone was obtained from C.T scan image of patient, thendata transferred to ANSYS program for modeling then load applied and solve the equation by the program,Specified nodes were selected at the rings of crestal bone (cortical bone) and cortical cancellous interface aroundeach dental implant and fixed for all models to monitor the stress change in that regions of different design of MIROD..After load application, Specified nodes were selected at the rings of crestal bone (cortical bone) and corticalcancellous interface around each dental implant and fixed for all models to monitor the stress change in thatregions of different design of MIR-OD .Results: In the present study the stress distribution and maximum stresses value around dental implant had arelationship to the number of dental implant. , The result appeared that the maximum stresses and means of stressesvalue was lower in the first group of models (which was supported through the use four dental implant) than thesecond group of models (which was supported through the use of two dental implant only). For the first group ofmodels the maximum stresses value around mesial implant was11.67, 10.51, 10.98 and 10.72 Mpa, while the maximumstresses around distal implant was 21.33, 18.51, 18.86, and17.56 Mpa for models 1,2,3 and 4respectively ,and thestresses around implant supporting second group of models was 22.52, 22.16, 20.51 and 19.60 Mpa for models5,6,7and8 respectively .Statistical analyses of means value appeared that there was statistically significant differencein stresses means value around implant of the second group with that’s values around mesial and distal implantsupporting first group of model . Regarding the result of both ball and bar system, it has been demonstrated thatstress was greater with ball attachment and MIR-OD supported by the use of four dental implants and anchored bybar attachments with distal extension gives the minimum values of stresses than the rest models. Also the results showthat higher stresses value was appeared at the cortical bone ring surrounding dental implant especially the distalimplant nearest to the free end extension area. Also it was appeared that the best model was Mandible implantretainedoverdenture that’s anchored by bar with distal extension and support by four dental implant .Conclusions: Bar-clips with distal extension mode of attachment considered the best type in producing the leaststresses around dental implant regardless number of dental implant used

Keywords

Implant --- overdenture --- stresses --- bar --- ball


Article
Effect of denture adhesives on the retention of maxillary complete denture

Authors: Ibrahim K. Ibrahim ابراهيم خالد ابراهيم --- Yaarob M. Salman يعرب محمد سلمان
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2005 Volume: 17 Issue: 1 Pages: 30-34
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: Using of denture adhesives improved the retention and stability of complete denture, so it is important for the success of complete denture treatment when it is used according to its indications.Materials and methods: This project was carried out in an attempt to measure and compare the effectiveness of denture adhesives (Boots, Super corega, and Lacalut denture adhesive) in a well fitting maxillary complete denture at various time intervals. The retention of well fitting maxillary complete denture with saliva alone and with the use of denture adhesives at different time intervals was measured as a resistance to dislodgment using loading apparatus.Results: The study revealed that there is a highly significant improvement in the retention of a well fitting maxillary complete denture after using any one of the three types of the denture adhesive. Statistically the three type of denture adhesives used in this study have approximately the same effectiveness with slightly difference in the time of action.Conclusion: The use of any type of these denture adhesives that were accepted by patient (whether vegetable gum or synthetic polymer, powder or paste) can improve the retention of the complete denture.


Article
Effect of adding Potassium Alum powder on the Mechanical Properties and Flame-resistant of Low Density of Polyethylene (LDPE)
تأثير إضافة مسحوق شب البوتاسيوم على الخواص الميكانيكيه ومقاومة اللهوبية للبولي اثيلين واطئ الكثافة (LDPE)

Authors: Ahmed J. Mohammed أحمد جاسم محمد --- Ibrahim K. Ibrahim إبراهيم كاظم إبراهيم --- Fayez J. Mohammed فائز جمعة محمد
Journal: JOURNAL OF THI-QAR SCIENCE مجلة علوم ذي قار ISSN: 19918690 Year: 2014 Volume: 5 Issue: 1 Pages: 46-51
Publisher: Thi-Qar University جامعة ذي قار

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Abstract

The Study of the Effect of Potassium Alum on the Mechanical properties of low density polyethylene (LDPE), which is manufactured in the General state company of petrochemical industries, Basra, as function of the percentages of Potassium Alum (2.5%, 5%, 10%, 15%, 20%), at particular size (150 µm) were investigated through several variables, such as, Young's modules, strength, and elongation. The obtained results were appeared that the added Alum to reduce the spaces between the polymer chains, which reflects the high ability of the polymer against the applied stress, and this increase will give further property that increase the hardness of the prepared specimens, the results lead to that the strength at both break will be affected little till the percentage (5%), and lowered after that with increasing the percentage also indicate an lowered in young's modules at the percentage (10%). The results also appear that the highest point of the stress is (10.95 N/mm2 ).The proportional limit was (163.6 N) for (10%), observe that the average time of burning starts strong impact when (5%) as increasing to(162 Sec) and then begins to decline behavior when increasing proportions weighted exception to this behavior when (20%).

تم إضافة مسحوق شب البوتاسيوم كحشوات مالئة وبنسب وزنيه (2.5%,5%,10%,15%,20%) وعند حجم دقيقه أما اقل أو مساو إلى (150 m) لبوليمر الاثيلين واطئ الكثافة LDPE والمصنع في معمل بتروكيمياويات البصره إذ تمت دراسة عدة متغيرات مثل الاستطالة وقوه الشد عند الوهن والقطع ومعامل يونك وبينت النتائج المستحصله ان الشب المضاف يعمل على تقليل الفراغات بين السلاسل البوليمريه مما يعكس إمكانية البوليمر العالية بتحمل الإجهاد المسلط عليه وتكون درجة التجانس عالية بين كل من البوليمر والحشوات، وان زيادة نسبة المالئات تضفي زيادة صفة الصلابة على النماذج المحضرة عند النسبة المئوية (%5)،ودللت النتائج إن سلوك قوة الشد عند القطع يكون ذا تأثير عند النسبة (% 5) من المضاف بعدها تهبط بزيادة كمية المضاف إذ تكون لمسحوق الشب كمواد مالئة تأثير على خصائص البولي اثيلين والذي له خصائص ميكانيكية ضعيفة لذلك تنخفض قوة الشد عند القطع ويلاحظ ايضا انخفاض معامل يونك مع نسبه المضاف (%10) مما يعكس مرونة البوليمر المطعم بشب البوتاسيوم وتوسع مدى التطبيقات لهذا البوليمر وبينت النتائج ان أعلى نقطه للإجهاد هي) .95 N/mm210)،وكانت أعلى قيمة لحد التناسب (proportional limit) 163.6 N للنسبة الوزنية % 10، ونلاحظ بان معدل زمن الاحتراق يبدأ بتأثير قوي عند النسبة (%5) إذ تصل قيمته إلى (162 Sec) وبعدها يبدأ السلوك بالانخفاض عند زيادة النسب الوزنية ويشذ هذا السلوك هند النسبة الوزنية (% 20).

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