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Evaluation of shear bond strength of silicon-based soft liner to the acrylic resin denture base using different polymerization technique with different storage periods in distilled water

Author: Thikra M. Hachim ذكرى هاشم
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2012 Volume: 24 Issue: 3 Pages: 42-46
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: This study was to investigate the effect of different polymerization techniques of denture base(conventional heat cure acrylic and visible light cure acrylic) and storage duration on shear bond strength of siliconbasedsoft lining material.Materials and methods: The soft liner investigated was a silicon-based autocured (Ufi Gel P). The soft liners wereprocessed according to manufacturers instruction. The resilient liner specimens for shear bond strength testing were25 ´ 25 ´ 3 mm and were processed between two acrylic blocks (size of each block (75x25x5mm). A total of 40specimens were fabricated, 20 specimens for each type of denture base specimens were stored for 1 day, 1 week,1 month and 3 months in distilled water at 37 degree oC (n=5).Bond strength was measured by instron testing machine at cross head speed 5mm/min until fracture. ANOVA withmultiple comparisons LSD test and student t-test were used to analyze the data (the mean difference is significant atthe 0.05)Results: The result indicated that type of denture based affect the bond strength of soft lining material and the shearbond strength of lining material decrease with storage duration (for both groups).Conclusion: Within the limitations of this in Vitro study: Ufi Gel P exhibited as significant higher bond strength to heatcured acrylic denture base when compared to visible light cure acrylic resin. Water storage for 1 month and 3 monthresult in significant decrease in shear bond strength of Ufi Gel P soft liner to a heat cured and Visible light cureddenture base.


Article
Evaluation of the effect of addition of polyester fiber on some mechanical properties of heat cure acrylic resin

Authors: Thikra M. Hachim ذكرى هاشم --- Zainab S. Abullah زينب عبد الله --- Yasamin T. Alausi ياسمين الالوسي
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2013 Volume: 25 Issue: special issue 1 Pages: 23-29
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: This study aimed to evaluate the effect addition of polyester fibers on the some mechanical propertiesof heat cured acrylic resin (implant strength, flexural strength and hardness)Materials and methods: Ninety specimens were used in the study. Thirty specimens were used for impact strengthmeasurements (80mm X 10mm X 4mm) length, width and thickness respectively. The specimens divided into threetest groups (n=10), first group formed from heat cure acrylic resin without fiber reinforcement. Second group wasformed from heat cure acrylic resin was reinforced with 2 mm length polyester fiber and third group was formed fromheat cure acrylic resin reinforced with 4mm length polyester fiber, impact strength measured by impact testingdevice. 30 specimens with (65 mm X 10mm 2.5mm) length, width and thickness respectively were used in 3 groups(n=10) flexural strength test. The flexural strength was measured by using flexural testing device. 30 specimens with(65mm X 10m X 2.5mm) length width and thickness respectively were used for hardness test. The specimens weredivided into 3 group (n=10) as in impact strength and flexural strength.Hardness measured by using (shore D hardness tester TH210).Results: revealed statistically significant increase on impact strength especially on 4mm length when compared tocontrol group. Significant decreases in flexural strength of PMMP. When compared to control group with 4mm lengthfiber reinforcement. Non significant decrease when compared control group with 2mm length fiber reinforcedPMMA. Significant decrease in hardness of PMMA resin after reinforcement with 2mm, 4mm lengths polyester fibers.Conclusions: Strengthening with the polyester fiber decreased the flexural strength and hardness of the resin, butincreased impact strength. Thus when high impact acrylic resins are needed, fiber reinforced resins may be thematerial of choice

الھدف من ھذا البحث لتقییم تاثیر اضافة الیاف البولیستر للاكریلك الحراري على بعض الخواص المیكانیكیة للاكریلك الحراري (مقاومة الصدمة ,قوة الطي,صلادة السطح).استخدم في البحث 90 نموذج وقد قسمت الى 30 نموذج لكل خاصیة , 30 نموذج لقیاس قوة الصدمة بقیاسات ( 80 ملم* 10 ملم* 4ملم) الطول , العرض,السمك بالتتالي النماذج قسمتالى ثلاثة مجموعات (العدد= 10 ) للاختبار المجموعة الاولى شكلت من الاكریلك الحراري بدون اضافة الالیاف ,المجموعة الثانیة شكلت باضافة الالیاف بطول 2ملم,المجموعة الثالثةشكلت باضافة الالیاف بطول 4ملم. مقاومة الصدمة قیست بواسطة جھاز قیاس الصدمة .30 نموذج استخدمت لقیاس قوة الطي بقیاسات ( 65 ملم* 10 ملم* 2,5 ملم)الطول ,العرض,السمك بالتتالي ,قسمت الى ثلاثة مجامیع( العدد= 10 ) لكل مجموعة وتم قیاس قوة الطي بجھازقیاس قوة الطي. 30 نموذج استخدمت لقیاس صلادة السطح بنفس القیاسات المستخدمة لقیاس قوة الطي .عكست النتائج زیادة ملحوظة في مقاومة الصدمة وخاصة بعد اضافة الالیف بطول 4 ملم ونقصان ملحوظ في قوة الطي بعد اضافة الالیف بطول 4ملم مع نقصان غیر ملحوظ بعداضافة الالیاف بطول ال 2ملم. نقصان غیر ملحوظ لكلا الطولین على صلادة السطح. ھذه الدراسة استنتجت ان اضافة الیاف البولستر تقلل من قوة الطي والصلادة ولكن تزید من مقاومةالصدمة ولذلك عندما نرید ان نستخدم الاكریلك الحراري ذو المقاومة العالیة للصدمة نستخدم الاكریلك الحراري المدعم بالیاف البولیستر

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