Bovine hydroxyapatite (BHA) Strontium Oxide Composites O. Gunduz, 1,a L.S. Ozyegin, 1,b S. Dorozhkin, 2 O. Meydanoglu, 3 N.Eruslu, 3 S. Kayali, 3 G. Goller, 3 S. Agathopoulos, 4 F.N.Oktar, 1,c-d 1a Metal Education Department, School of Technical Education, Marmara University, Istanbul, Turkey. 1b Dental Technology Department, School of Health Related Professions, Marmara University, Istanbul, Turkey. 2 Kudrinskaja sq. 1-155, 123242 Moscow, Russia 3 Metallurgical & Materials Engineering Department, Istanbul Technical University, Maslak, Istanbul, Turkey. 4 Materials Science & Engineering Department, Ioannina University, Ioannina, Greece. 1c Industrial Engineering Department, School of Engineering, 1d Radiology Department, School of Health Related Professions, Marmara University, Istanbul, Turkey. 1a oguzhan@marmara.edu.tr, 1b sevgiozyegin@gmail.com, 2 sedorozhkin@yandex.ru, 3 meydanoglu@itu.edu.tr, 3 eruslu@itu.edu.tr, 3 kayali@itu.edu.tr, 3 goller@itu.edu.tr, 4 sagat@cc.uoi.gr, 1c-d foktar@eng.marmara.edu.tr, Keywords : Hydroxyapatite, Strontium Oxide, Sintering, Microstructure, Mechanical Properties. Abstract. Composites of calcinated bovine bone derived hydroxyapatite (HA) with 5 and 10 wt % SrCO 3 were prepared by sintering. The production of HA from natural sources is preferred due to money and time saving reasons. In this study scanning electron microscopy (SEM) investigations and together with measurements of microhardness, density, and compression strength were performed. The experimental results indicated that compression strength and microhardness values of HA-Sr-oxide composites decrease when the content of SrCO 3 and sintering temperature increase. The best compression strength values were achieved after sintering at 1000°C. It was seen that at higher temperatures the compression strength and the microhardness values decrease due to the pore formation. The pore formation is very important for scaffold formation for tissue engineering purposes. Introduction Biological apatites attract special interest since it is believed that the several substitutions at the Ca 2+ , PO 4 3− and OH − sites of HA and the presence of several trace elements play an important role in the overall physiological functioning and in the osseointegration process [1]. Due to the poor mechanical properties of pure HA, HA-based composite materials are preferred for load bearing biomedical applications. On the other hand, it is well known that in order to improve the strength of pure HA, ceramic reinforcements (i.e. fibres, whiskers, platelets or particles) can be added to HA [2]. It is well known from the literature that ionic strontium (Sr) in human body shares the same physiological pathway as calcium and can take place at the mineral structure of the bone, especially at the regions of high metabolic turnover. As a matter of fact, the beneficial effect of low doses of stable strontium in the treatment of osteoporosis, characterized by low bone mass loss and fracture risk, , was discovered almost half a century ago, and the effect was attributed to prevention of bone loss by mechanism of depressing bone resorption and maintaining bone formation. Since a long time ago, it is well documented in the literature that application of low electricity on various tissues can result in their healing with the help of a physiotherapist (broken bones, with microsurgery corrected full rupture of the hand or leg from the body). A new class of implantable medical devices, called BION ® s (for BIOnic Neurons) was developed. This device can provide precise interfaces between electronic controllers and muscles. Separately addressable BION ® s can be injected into various sites, where they receive power and digital command data from a single Key Engineering Materials Vols. 396-398 (2009) pp 407-410 online at http://www.scientific.net © (2009) Trans Tech Publications, Switzerland All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of the publisher: Trans Tech Publications Ltd, Switzerland, www.ttp.net. (ID: 91.77.103.54-03/09/08,17:54:34)