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Article
Effect of Addition of ZrO2 on Biaxial Flexural Strength of Calcium Phosphate Ceramics

Authors: R.Van Noort --- Maher K. Ali --- Mohammed Y.Shareef --- Mohammed K. Hilal
Journal: Tikrit Journal for Dental Sciences مجلة تكريت لعلوم طب الاسنان ISSN: 20731213 Year: 2014 Volume: 3 Issue: 1 Pages: 38-46
Publisher: Tikrit University جامعة تكريت

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Abstract

AbstractThe aim of this study is to investigate the effect of addition of ZrO2 on the biaxial flexural strength (BFS) of ceramics fabricated using a conventional powder technology. Various compositions of hydroxyapatite (HAp) Ca10(PO4)6(OH)2 and zirconia powder ZrO2, ranging from 10 to 90 wt% ZrO2, were prepared using a wet mixing process. Ten compacts (13.5mm3mm) were made for each group, pressed and sintered in air at sintering temperatures from 1100 to 1450oC for up to 12 hours. The bulk density, porosity, linear shrinkage and BFS. The porosity reduced and linear shrinkage increased with increasing sintering temperature and amounts of zirconia, whereas the sintering time had little effect. The highest mean value achieved for the BFS was 26920 MPa for a composition of 70% ZrO2 and 30% HAp fired at 1450oC for 6 hours. From the experimental results can be conclude that sintering temperature and composition affect densification behaviour of calcium phosphate/ ZrO2 composites. The BFS increases with a reduction of porosity and increases with both sintering temperature and additions of ZrO2. It was noted that there is considerable scope for improvement in the BFS values by reducing the porosity of these composites.


Article
Characterizations of Hydroxyapatite Thin Films Deposited by Spray Pyrolysis on Titanium Substrates for Bone Implant Applications

Authors: Walid K. Hamoudi --- Raid A. Ismail --- Hadeel F. Abbas
Journal: Iraqi Journal of Applied Physics المجلة العراقية للفيزياء التطبيقية ISSN: 18132065 23091673 Year: 2014 Volume: 10 Issue: 3 Pages: 11-16
Publisher: iraqi society for alternative and renewable energy sources and techniques الجمعية العراقية لمصادر وتقنيات الطاقة البديلة والمستجدة

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Abstract

Hydroxyapatite (HAp) synthesis was accomplished by spray pyrolysis to coat titanium bone implant with a thin film of this material. Thin films of HAp were prepared under different deposition temperatures and spraying time. Fourier transform infra-red spectroscopy (FTIR), atomic force microscope (AFM), X-ray diffractrometer (XRD), and Vickers’s hardness measurements were employed to characterize the synthesized films. The results indicated titanium surfaces coated by 224.1 HV, 8.59 nm thick carbonated hydroxyapatite films of 1.33 nm surface roughness.


Article
Effects of Sintering Temperature on the Composite Titanium-hydroxyapatite Used in Bones and Teeth Ceramic's Application
تأثير التلبيد الحراري على المتراكب تيتانيوم-هيدروكسي ابتايت المحضر لتطبيقات سيراميك العظام والاسنان

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Abstract

A new system of functionally graded bones and teeth materials is considered in this study by sintering titanium with hydroxyapatite powders. Hydroxyapatite (HAP) was prepared by sol-gel method through the addition of pentoxide phosphoric acid to the suspension of calcium nitrate to give the ratio of Ca/P 1.67 by the limiting controlling of the variables like (pH, reaction temperature, ripening period and sintering temperature). Then HAP product was mixed with titanium powder at different ratios (20-60 wt), Followed by sintering temperature in range of 1000 and 1100ºC. The bioactivity was tested in simulated body fluid (SBF) by immersing the samples at several interval periods (1-4 weeks). The mean particles size was found in the range of 100 nm which considered to be convenient for using in medical applications

في هذا البحث اعتمدت طريقة جديدة في تحضير متراكبات سيراميك العظام والاسنان والتي تشمل عملية تلبيد مركب الهيدروكسي ابتايت بمسحوق التيتانيوم ، حيث تم اولا تحضير مركب الهيدروكسي ابتايت (HAP) باستخدام طريقة السائل الهلامي(صول-جيل) وباختيار مواد التفاعل (خامس اوكسيد الفسفور ونترات الكالسيوم المائية) ومن خلال السيطرة الدقيقة على المتغيرات التي تؤثر على سير التفاعل من اجل الحصول على المنتج المطابق للاستخدام الطبي وبالنسبة المعتمدة (Ca/P 1.67) وهي ( الدالة الحامضية ، درجة حرارة التفاعل ، فترة الانضاج ودرجة حرارة التلبيد). ثم أجري خلط نسب مختلفة (20-60%) من مسحوق التيتانيوم مع مسحوق الهيدروكسي ابتايت المحضربالطريقة اعلاه ، وبعد ذلك لبدت العينات بدرجات حرارية تراوحت بين 1000- 1100م◦ من اجل التوصل الى منتج مطابق كيميائيا وبايولوجيا لمادة العظم القياسية. قياسات التوافقية الحياتية تمت بغمر النماذج المحضرة في مشابهات محاليل الجسم لمدة 1-4 اسبوع وقد وجد من خلال البحث ان سمك طبقة الهيدروكسي ابتايت على سطوح النماذج المغمورة كانت بمعدل 100نانومتر وهي ملائمة للتطبيقات الطبية كونها مشابهة لسيراميك العظم الطبيعي

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