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Article
The effect of different storage times and storage conditions of two types of alginate impression on accuracy of master cast

Authors: Najlan A JASIM --- Munther N KAZANJI
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2001 Volume: 1 Issue: 3 Pages: S363-S374
Publisher: Mosul University جامعة الموصل

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Abstract

The aims of this study were to determine the effect of using different storage time and storage media on the accuracy of two types of alginate impression material,Hydrogum soft and Hydrogum elastic.One hundred sixty impressions were recorded from a standard acrylic model using perforated trays. These impressions were divided into three main groups. In the first group,(48) impressions were stored at (3) times interval namely (15) minutes,(30) minutes,(60) minutes and left on the bench uncovered. In the second one,(48) impressions were stored in disposable plastic bags at the same time interval mentioned above. In the third one,(48) impressions were divided into (3) subgroups, the first one were only washed with tap water before pouring, the other two subgroups were immersed in Sodium Hypochiorite(0.5%) and ChlorhexidineGluconate(0.5%) disinfectant solutions for (30) minutes before pouring,(16) impression will be taken and poured immediately to be considered as a control for this study.A three dimensional measuring machine (3D) was used for measuring the dimensional change of stone casts, the results showed that there was no significant differences of casts accuracy produced from the two types of an alginate impression material.Storage of alginate impression material at (15) and (30) minutes on the bench or inside sealed plastic bags showed no significant differences in dimensional changes compared with control samples that poured immediately, Storage to (60) minutes showed a significant difference,washing alginate with tap water and immersion in chlorhexidine disinfectant solution (0.5%) for (30) minutes showed no significant difference Immersion in sodium hypochlorite (0.5%) for (30) minutes showed significant changes.It was concluded that alginate impression could be stored for (30) minutes inside bags without significant changes if the pouring of alginate impression will be delayed for any reason.


Article
COMPARISON STUDY OF THE SHEAR BOND STRENGTH BETWEENPOLYETHER AND ADDITION SILICONE IMPRESSIONMATERIALS

Author: Saad F. Oboudi
Journal: Al-Nahrain Journal of Science مجلة النهرين للعلوم ISSN: (print)26635453,(online)26635461 Year: 2009 Volume: 12 Issue: 3 Pages: 56-63
Publisher: Al-Nahrain University جامعة النهرين

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Abstract

Abstract
The impression material is used mainly in the area of removable partial and complete denture
and in the construction of inlays, crowns and bridges. They are used also in dental laboratories for
duplicating master casts.
Recent studies have evaluated the bond strength of selected impression materials. This research
was performed to study the shear bond strength of impression materials to tray by testing forty
samples, each of which consisted of two blocks of acrylic with the impression material sandwiched
between them. Tray adhesive was used to increase adhesion between impression material and
custom tray. Also this research showed that by the use of perforation impression materials adhere
firmly to the impression trays. Therefore perforation - adhesive combination gave acceptable
results.
Experimental results indicated that polyether impression material showed higher shear bond
strength values to cold-cure acrylic than addition silicone impression material for both control and
perforated samples without adhesive application. The shear mean bond strength values of polyether
to the tray material after adhesive application were decreased. While, the shear mean bond strength
increased significantly when addition silicone was used with the adhesive and with the combination
samples.


Article
Dimensional accuracy of impression tec-hniques for the endosteal implants (An in vitro study): Part I

Authors: Nadira A Hatim --- Basim M Al–Mashaiky
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2007 Volume: 7 Issue: 1 Pages: 20-31
Publisher: Mosul University جامعة الموصل

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Abstract

Aims: To detect the most accurate impression materials and technique to transfer single or multiple implants position from the master model to the stone dies by two methods of measurement. Materials and methods: Two master models (Cl III Kennedy with single implant Frialit–2, and Cl II free end saddle with double implants) were fabricated. Four impression techniques were used (direct, and indirect, each with one, and two steps) using condensation, addition (heavy and light consistencies) and addition (medium consistency) silicone impression materials. Five impressions were taken for each technique to produce a total number of 100 stone casts. A mechanical apparatus was carefully designed to allow constant repeatable position of stock impression tray to the master model, and to allow vertical removal of the impression tray that helps to standardize the path of removal. The measurements were performed by using digital caliber and optical micrometer microscope. Results: Showed that the direct (open tray) two steps technique was the accurate technique for transferring implant position to the laboratory cast. The two steps impression technique was the most accurate one than one step. There were no significant differences between single, and double implants. There was significant difference between the two methods of measurements in (Z) axis for both single and double implants case. Conclusion: The direct (open tray), two steps impression technique, and addition impression material is the most accurate technique. The numbers of dental implants had no significant effect on accuracy of stone cast.


Article
Disinfection Of Alginate And Silicon Impressions By Using UV And Blue Light. (In Vivo Study)

Authors: Mohammad T.AL- Khafagy --- Israa K. AL-Yasiri --- Suhad Jabbar Hamed
Journal: kufa Journal for Nursing sciences مجلة الكوفة لعلوم التمريض ISSN: 22234055 Year: 2013 Volume: 3 Issue: 2 Pages: 184-191
Publisher: University of Kufa جامعة الكوفة

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Abstract

There is growing concern about the issue of cross-infection in dental clinics and laboratories. There are many methods of disinfection for impression material; but these conventional strategies present several disadvantages .In this study we introduce the UV and blue light as effective savable method for the disinfection of the impression. Aim: The purpose of this study was to evaluate the disinfection potential of UV and blue light on alginate and silicon impression material. Material and methods: Forty college students were randomly selected from Collage of Dentistry in University of Kufa during the period between 1 December 2011 to 1 October 2011. And 40 alginate and silicon impressions were taken and grouped according to time of exposure (10 and 20 minutes). Each impression was cultured on blood agar and Mackonky agar before treatment with UV light or blue light, the treatment was done after 10 and 20 minutes; then cultured for bacterial inspection. The data were analyzed statistically using Chi-square test and P-value 0.05. Result: The culture showed that all the silicone impressions gave a positive result after treatment with blue light and UV light except a group that treated with UV light for 20 minutes, which showed significant reduction in the bacterial growth. All the alginate impressions give positive culture after treatment with UV and blue light after 10 and 20 minutes. Conclusion: From this study, we conclude that the silicon impression can be sterilized with UV light when treated for 20 minutes.

هناك قلق متزايد حول قضية العدوى في عيادات طب الأسنان والمختبرات. هناك العديد من أساليب التطهير لمواد الطبعة , ولكن هذه الاستراتيجيات التقليدية تحتوي عدة عيوب. في هذه الدراسة نقدم ضوء الأشعة فوق البنفسجية والزرقاء كطريقة فعالة وأمينه في تطهير مادة الطبعة.هدف الدراسة : إن الغرض من هذه الدراسة هو تقييم إمكانية تطهير ضوء الأشعة فوق البنفسجية والزرقاء على مادة السيلكون والالجنيت المكونة للطبعة.المواد وطرائق العمل : أربعون طالب كلية تم اختيارهم بشكل عشوائي من كلية طب الأسنان جامعة الكوفة في الفترة من الأول من شهر أيلول إلى الأول من شهر كانون الأول وتم اخذ أربعون طبعة من السليكون والالجنيت وتم تصنيفها وفقا لوقت التعرض (10 و 20 دقيقة). كل طبعة تم زراعتها على وسط أكار الدم ووسط الماكونكي قبل تعريضها لضوء الأشعة الفوق البنفسجية والضوء الأزرق وبعد معاملتها بضوء الأشعة الفوق البنفسجية والضوء الأزرق لمدة 10 و 20 دقيقة. وقد تم تحليل النتائج باستخدام مربع كاي ضمن القيمة المعنوية 0.05 . النتائج: أظهرت نتائج الزرع أن كل طبعات السليكون أعطت نتائج موجبه بعد معاملتها بضوء الأشعة الفوق البنفسجية والضوء الأزرق ماعدا المجموعة التي عرضت للأشعة فوق البنفسجية لمدة 20 دقيقة والتي أظهرت اختزال معنوي في النمو البكتيري.أما بالنسبة لطبعات الالجنيت فأعطت نتيجة موجبه للزرع البكتيري بعد تعرضها لضوء الأشعة الفوق البنفسجية والضوء الأزرق لمدة 10 و 20 دقيقة.الاستنتاجات : من هذه الدراسة نستنتج أن يمكن تعقيم طبعات السيلكون بضوء الأشعة فوق البنفسجية عندما تعامل لمدة 20 دقيقة.


Article
The effect of disinfection procedure and storage on wettability of hydrophilized condensation silicone impression materials

Author: Dr. Suha Fadhil Dulaimi / Assistant professor د. سها فاضل
Journal: MUSTANSIRIA DENTAL JOURNAL مجلة المستنصرية لطب الاسنان ISSN: 18138500 Year: 2016 Volume: 13 Issue: 1 Pages: 11-18
Publisher: Al-Mustansyriah University الجامعة المستنصرية

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Abstract

Background: a newly developed hydrophilized condensation silicone impressionmaterial claimed to be hydrophilic, but exposure to disinfection procedure andstorage could alter the wettability of impression material. Thus, the aim ofpresent study was to evaluate the effect of impression disinfection by immersionin 0.5% NaOCl for 10 mints. on wettability of hydrophilized condensationsilicon . In addition, effect of storage after disinfection for two hours, measuredby contact angle of dental stone mix with impression surface.Materials and Methods: Hydrophilized condensation silicone (putty and wash type)tested with type III dental stone and 0.5% sodium hypochlorite disinfectantsolution were used in this study. Disinfection procedure by immersion for 10mint. Wettability was evaluated in simulation of regular clinical situation pouring2ml. of stone slurry on impression surface to form stone patty. Each pattysectioned into two halves, scanned with flat bed scanner and images printed.Dental stone mix contact angle with impression surface was measured withprotractor from scanned image of the cross section of stone patty. Measurementswere preformed before and after disinfection procedure, also after storage inhumid environment for two hours.Results: The putty type showed significant difference p<0.001 when subjected todisinfection and storage. The wash type showed no significant difference p>0.05when subjected to disinfection or storage. Both types together they were notaffected by disinfection procedure p>0.05, but storage had significant effectp<0.001 on wettability.Conclusions: For the hydrophilized condensation silicone using both types together(putty + wash) for making impression improve wettability even afterdisinfection. Delay pouring impression for two hours cause deterioration ofimpression wettability.


Article
Cross arch and antero–posterior dimensional changes of impressions and stone casts at different storage times

Author: Sawsan H Al–Jubori
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2003 Volume: 3 Issue: 1 Pages: 74-81
Publisher: Mosul University جامعة الموصل

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Abstract

The aim of study is to evaluate the linear dimensional changes (cross arch, antero–posterior dimensions) of impressions and die stone casts of two brands of addition silicone impression materials (Express and President) for special master model using two–steps (putty–wash) technique, at different storage times before pouring of impression, by using of three dimensional measuring machine and to compare between the accuracy of the two brands of impression materials. The results indicated that a significant difference between the interabutment distances of impression and die stone casts. The Express impression materials produce the most accurate results. There is slightly increase in interabutment distances of stone casts. At one hour storage time there are the smallest dimensional changes of impressions and stone casts in relation to construction of complete–arch fixed partial denture.


Article
Measurement of surface roughness of the stone cast poured on different impression materials

Authors: Munther N KAZANJI --- Lamia T REJAB
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2001 Volume: 1 Issue: 3 Pages: S237-S246
Publisher: Mosul University جامعة الموصل

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Abstract

The aim of this study was to determine the mean roughness values of the stone casts Surfaces that were poured from two different gypsum products (ZETA and QD) dental stones on the three different impression materials (Supersil,Neogenate and Xanthano).Ten patients were selected to perform this study, for each patient six impressions were recorded. Sixty stone casts were poured and examined to evaluate surface roughness values. The stone casts were tested for surface roughness values with surface-roughness-measuring instrument,Profilometer(Perthometer).The data were statistically analyzed using ANOVA and Duncan's multiple range test.The results of this study showed that there were a significant differences in the mean roughness values of the stone casts among the three different impression materials and two different dental stones used at alevel of (P≤0.05).It was concluded that the smoothest surface of the stone cast were obtained from poured ZETA stone on Supersil impressions, while roughness surface were observed on the stone casts produced from poured QD dental stone on Xanthano impressions.


Article
Volumetric changes in acrylic denture base material

Authors: Nadira A HATIM --- Sameer M RASHAD
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2002 Volume: 2 Issue: 3 Pages: 314-326
Publisher: Mosul University جامعة الموصل

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Abstract

Aims of this study are to determine:a-Three dimensional chances (Volumetric changes) of the internal surfaces of twenty four maxillary acrylic resin complete denture bases in relation to their corresponding master casts, were determined among six patients by using three dimensional measuring machine {Cordimet 1200}.b-The maximum dimensional change of the acrylic resin denture that can be allowed to avoid displacement of the tissue.c-The effect of muco-static impression technique on the tissue displacement.Three maxillary dentures A, B, and C were constructed in the conventional way. Dentures B, and C were designed by increasing the space between the internal surface of the denture and the tissue surface of themaster cast by using tinfoil (0.2)mm, and (0.3)mm except the periphery region respectively.By the aid of computer, three special programs were designed for this study to, calculate the surface area,volumetric changes in acrylic denture base, and to draw any section of the tissue surface of the oral cavity in relation to the tissue surface of the denture every (5)mm longitudinally, and (2)mm horizontally.The results of this study showed that maximum tissue displacement was found in the midline region toward the posterior part of the denture base (27.465 mm).The area of tissue displacement was reduced toward the periphery, away from the midline of the maxillary arch. While in the post-dam region, tissue displacement was found in the middle part of the palate.In the periphery region there was a convergence of buccal flanges toward the middle of the denture base.A positive volumetric change in denture base was found in moral region (0.072 mm3). The results of muco-static impression technique was a pressure on the tissue to 0.3 mm vertically lead to have negative volume equal to (0.00 mm3).


Article
The effect of disinfectants on the surface quality of irreversible hydrocolloid impression material and gypsum cast

Authors: Suha F. Dulaimi --- Zahraa N. Al-Wahab
Journal: nursing national Iraqi specility المجلة العراقية الوطنية للعلوم التمريضية ISSN: 18122388 Year: 2012 Volume: 25 Issue: 1 Pages: 95-100
Publisher: Baghdad University جامعة بغداد

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Abstract

Objective: To evaluate the changes in the surface quality of irreversible hydrocolloid impression material hydrogum following disinfection with 0.525% sodium hypochlorite, 0.2% Chlorehexidine Gluconate, and 4% Povidone Iodine.Methodology: Forty specimens of alginate impression materials hydrogum were fabricated according to the ISO 1563 and were divided into four groups according to the method of solution dipping: group 1: Dip in 0.525% sodium hypochlorite, group 2: Dip in 0.2% chlorhexidine gluconate, Group 3: Dip in 4% Povidone Iodine, Group 4: No treatment with any solution (control group). Then the specimens were poured in type II stone. Surface detail was determined using a stainless steel block in accordance with ISO 1563. Results: The results were subjected to Kruskal – Wallis non parametric test showed no statistical significant difference in the effect of the disinfection solution on the surface detail quality (P – value 0.392, at p> 0.05). However, the surface quality of the specimens disinfected by sodium hypochlorite showed some degree of erosion or damage to the surface quality of the resultant cast, but the difference was not statistically significant. Recommendations: make microbiological study to evaluate the effect of disinfectant solutions on different microorganisms present in the oral cavity and evaluate the hardness of impression material following the use of disinfectant solutions.

الهدف: من اجل تقييم التغييرفي نوعية السطح لمادة الطبعة الغروية المائية هايدروكام غير المعكوسة بعد تطهيرها بصوديوم هايبوكلورايت 525, 0 %, كلورهيكسيدين كلوكونايت 0,2% , بوفيدون ايودين 4%. المنهجية: تم تصنيع 40 عينة من مادة الطبعة الجينيت وفقا للقياس اي اس او 1563 وتم تقسيمها الى اربع مجاميع وفقا لطريقة الغطس في المحلول: المجموعة الاولى تغطس في صوديوم هايبوكلورايت 525, 0 %, المجموعة الثانية تغطس في كلورهيكسيدين كلوكونايت 0,2%, المجوعة الثالثة تغطس في بوفيدون ايودين 4%, المجموعة الرابعة لاتغطس في اي محلول (التحكم). بعد ذلك تم صب العينات في مادة ستون نوع 2. تفاصيل السطح تم قياسها باستعمال قالب ستينليسس ستيل.النتائج: باستعمال اختبار كروسكيل واليس , اظهرت النتائج عدم وجود فرق محسوس في تأثير محاليل المطهرات على نوعية تفاصيل السطح لكن استعمال محلول صوديوم هايبوكلورايت ادى الى تاكل او ضرر في نوعية سطح القالب وهذا الفرق احصائيا غير محسوس.التوصيات:اجراء دراسة مختبرية لبيان تأثير محاليل المطهرات على انواع مختلفة من الجراثيم الموجودة في الفم واجراء فحص صلادة مادة الطبعة بعد استعمال محاليل المطهرات.


Article
An in Vitro Study to Evaluate the Accuracy of Addition Silicone and Polyether Impression Materials after Different Pouring Time.

Authors: Makdad Najeeb Chakmakchi --- Manaf Basil Ahmed
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2016 Volume: 16 Issue: 1 Pages: 10-18
Publisher: Mosul University جامعة الموصل

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Abstract

Aims: To evaluate the accuracy of two different impression materials and to evaluate the effect of time of pouring on the accuracy of impression. Materials and Methods: Four parallel implant placed in foam arch to obtain study model. Medium body addition silicone and medium body polyether are used. 20 impressions of study model were taken under monophase technique, 10 by addition silicone and 10 by polyether by closed tray technique, half of them were pour after one hour and another half of the impressions were poured after 24 hours by die stone to obtain casts. By using Traveling microscope three linear measurements were measured between 4 implants and comparsime was made between distances on the model and on the casts to assess the dimensional changes of impression materials. Results: Statistical analysis of data by paired sample T-test at (p≤0.05) reveals no significant difference in the accuracy of each material after one and 24 hours and the results analyzed by independent samples T-test reveals no significant difference between materials after one and 24 hours under closed tray technique (dimensional change don’t exceed 1%). Conclusions: The results appeared that there is no difference in the accuracy between addition silicone and polyether and there is no effect of time (1h-24h) on the accuracy of impression, also results showed the high dimensional stability of two materials.

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