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Article
The effect of thermocycling on microleakage analysis of bulk filled base composite in comparison to incrementally placed nanohybrid composite in class II MOD restorations (An in vitro study)

Authors: Lena A. Hassan --- Adel F. Ibraheem
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2013 Volume: 25 Issue: 3 Pages: 28-34
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: The study aim was to evaluate thermocycling effect on microleakage of occlusal and cervical marginsof MOD cavity filled with bulk filled composites in comparison to incrementally placed nanohybrid composite and toevaluate the difference in microleakage between enamel and dentin margins for the three materials groups.Materials and method: Forty eight maxillary first premolars were prepared with MOD cavities. Samples were dividedinto three groups of sixteen teeth according to material used: Grandio: Grandio. SDR: SDR +Grandio. X-tra: X-tra base+ Grandio. Each group was subdivided into two according to be thermocycled or not. After 24 hrs immersion in 2%methylene blue, samples weresectioned and microleakage was estimated.Results: Thermocycling significantly increased microleakage at occlusal margin in Grandio group compared to othergroups. SDR composite use before and after thermocycling significantly reduced microleakage at occlusal andcervical enamel margins compared to other groups. Grandio group had non significant difference to X-tra group inmicroleakage before thermocycling at occlusal and cervical enamel margins while it had a significant increase afterthermocycling. No material had significantly reduced dentin margin microleakage before or after thermocycling.Only SDR group before thermocycling, significantly reduced microleakage in enamel margin compared to dentinmargin.Conclusion: Thermocycling did not increase microleakage in all the groups except for Grandio group in occlusalmargin. SDR group showed reduced microleakage in occlusal and enamel margins in comparison to othergroups.None of the materials reduced microleakage in dentin margin


Article
The influence of cavity design for cusp coverage on fracture strength of weakened maxillary first premolars using two esthetic restorative systems (CAD/CAM hybrid ceramic and nanohybrid composite) (An in vitro study)

Authors: Zainab Salman Jawad زينب سلمان جواد --- Abdul Karim J. Al-Azzawi عبد الكريم جاسم العزاوي
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2015 Volume: 27 Issue: 1 Pages: 1-10
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: Maxillary first premolar with wide MOD cavity more susceptible to fracture. The aim of this study was toassess the influence of cavity design for cusp coverage on the fracture resistance of weakened maxillary firstpremolar restored with CAD/CAM hybrid ceramic versus nanohybide composite.Materials and Methods: Fifty six intact maxillary first premolars of approximately comparable sizes were divided intoseven groups eight for each: Group A: Intact teeth (control group); Group B: teeth prepared for MOD inlay; Group C:teeth prepared for MOD onlay covering the lingual cusp; Group D: teeth prepared for MOD covering buccal andlingual cusps ,the previous three groups indirectly restored with nanohybrid composite (3M ESPE Z 250 XT); GroupE,F,G prepared with the same design as group B, C, D respectively and restored with CAD/CAM hybrid ceramic(VITA ENAMIC).Results: An axial compression test was used to measure the fracture strength of experimented teeth. The readingswere analyzed statistically by t-test, one way ANOVA and LSD, then the mode of fracture had been examined. Theresults showed that sound teeth in group (A) had more fracture resistance values than all experimental groups andthe difference were highly significant with group (B, E, F, G).When the influence of cavity design tested amongcomposite groups it showed highly significant difference between group (B) and (C)and the highest fractureresistance value was for group(C), whereas the influence of cavity design among Enamic groups showed highlysignificant difference between group (E) and (G) the highest fracture resistance value was for group(E).T-testbetween similar designs showed non-significant difference between MOD groups and highly difference betweenother groups.Conclusions: Cusp coverage increased the fracture resistance of composite groups but result in non-restorablefracture, while Enamic total onlay presented promising fracture resistance with favorable mode of fracture


Article
Preparation of Nanohybrid antifungal from Nystatin and determination its inhibitory efficiency against Candida spp.
Candida spp. تحضير مضاد فطري نانوي هجين من المضاد نستاتين وتحديد كفائته التثبيطية ضد

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Abstract

A nanohybrid antifungal Nys-ZnO was prepared using sol-gel ion exchange method betweenthe antifungal Nystatin (Nys) and Zinc Oxide. The new nanoantifungal was identified. FT-IRspectroscopy revealed the appearance of new groups in the Nys-ZnO spectrum which indicates theformation of new compound. The X-Ray Diffraction (XRD) spectrum revealed the appearance ofnew diffraction planes in the nanohybrid antifungal spectrum in compare with the spectrum of zincoxide. Scanning Electron Microscope (SEM) showed the presence of some change in the Nys-ZnOsurface. The two and three dimensional image of the above compound in atomic force microscopeconfirmed the formation of new antifungal with nanodimensions. The antimicrobial activity of thenanohybrid antifungal was studied against 23 isolates of Candida. Results showed that highestinhibition was obtained against isolate Candida tropicalis 4 with avarege inhibition zone of 24.08mm .

تم تحضير مركب نانوي هجينتم تشخيص المضاد الفطري النانوي الجديد ، اذ كشفت مطيافية الاشعة تحت . Zinc Oxide و اوكسيد الزنك Nystatin(Nys)مما يشير الى تكون مضاد فطري جديد كما اوضحت تقنية حيود Nys-ZnO الحمراء عن ظهور مجاميع جديدة في طيف المضادمقارنة بطيف حيود Nys-ZnO ظهور مستويات حيود جديدة في طيف المضاد (X-Ray Diffraction, XRD) الاشعة السينيةعن ظهور تغيرات (Scanning Electron Microscope ,SEM) أوكسيد الزنك . واثبت فحص المجهر الالكتروني الماسحالثنائية والثلاثية (Atomic Force Microscope ,AFM) في سطح المضاد النانوي كما اثبتت صورتي مجهر القوة الذريالابعاد ، الحصول على مركب ضمن الابعاد والمقاسات النانوية . درست الفعالية المضادة للإحياء المجهرية للمضاد النانوي قيدCandida tropicalis واوضحت النتائج ان اعلى فعالية تثبيطية كانت ضد العزلة Candida الدراسة ضد 23 عزلة من خميرة4 بمعدل تثبيط مقداره 24.08 ملم.


Article
Preparation of nanohybrid compound from the food preservative octyl gallate and studying some of its biological activities
تحضير مركب نانوي هجين من المادة الحافظة Octyl gallate ودراسة بعض فعالياته البايولوجية

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Abstract

A nanohybrid compound Mg/Al-OG-LDH was prepared using ion exchange method between the food preservative octyl gallate (OG) and Mg/Al layered double hydroxide. The new nanocompound was identified. FT-IR spectroscopy revealed the appearance of new groups in the Mg/Al-OG-LDH spectrum which indicates the formation of new compound. The X-Ray Diffraction (XRD) spectrum revealed the appearance of new diffraction planes in the nanohybrid compound spectrum in compare with the spectrum of layered double hydroxide. Scanning Electron Microscope (SEM) showed the presence of some change in the Mg/Al-OG-LDH surface. The two and three dimensional image of the above compound in atomic force microscope confirmed the formation of new compound with nanodimensions.The antimicrobial activity of the nanohybrid compound was studied against five species of gram positive bacteria. Results showed that highest inhibition was obtained against Staphylococcus aureus with an inhibition zone of 14 mm at 15 mg/ml concentration. The nanocompound was more efficient than the free compound OG in inhibiting the two toxin producers fungi Aspergillus flavus and Aspergillus parasiticus .Results of antioxidants activity showed the ability of the Mg/Al-OG-LDH in scavenging the free radical ATBS where the inhibition percent was at 75 µg/ml.

تم تحضير مركب نانوي هجين Mg/Al-OG-LDH باستخدام طريقة التبادل الايوني بين المادة الحافظة Octyl gallate (OG) وطبقات المغنيسيوم / الالمنيوم ثنائية الهيدروكسيد Mg/Al-NO3-LDH . تم تشخيص المركب النانوي الجديد ، اذ كشفت مطيافية الاشعة تحت الحمراء عن ظهور مجاميع جديدة في طيف المركب Mg/Al-OG-LDH مما يشير الى تكون مركب جديد كما اوضحت تقنية حيود الاشعة السينية (X-Ray Diffraction, XRD) ظهور مستويات حيود جديدة في طيف المركب Mg/Al-OG-LDH مقارنة بطيف حيود طبقات ثنائية الهيدروكسيد . واثبت فحص المجهر الالكتروني الماسح (Scanning Electron Microscope ,SEM) عن ظهور تغيرات في سطح المركب النانوي كما اثبتت صورتي مجهر القوة الذري (Atomic Force Microscope ,AFM) الثنائية والثلاثية الابعاد ، الحصول على مركب ضمن الابعاد والمقاسات النانوية .درست الفعالية المضادة للإحياء المجهرية للمركب النانوي قيد الدراسة ضد خمسة انواع من البكتيريا الموجبة لصبغة غرام واوضحت النتائج ان اعلى فعالية تثبيطية كانت ضد بكتيريا Staphylococcus aureus بقطر تثبيط مقداره 14 ملم عند التركيز 15 ملغم/ مل . كما تفوق المركب النانوي علـــــى المركب OG الحر فــي تثبيطه للفطرين المنتجين للسموم Aspergillus flavus و A.parasiticus .واوضحت نتائج الفعالية المضادة للأكسدة ان المركب النانوي Mg/Al-OG-LDH يمتلك القابلية على كسح الجذر الحر ABTS اذ كانت النسبة المئوية للتثبيط عند التركيز 75 مايكروغرام / مل .

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