Abstract:
Around the world about millions of people using the medical devices or biomaterials that implanted in side human body in order to replace the function of unwell tissues or damaged parts. In spite of the importance roles of these implants in saving or improving human life, many of them are failed during short period or having complications. The main failure of the biomaterials caused by unqualified biocompatibility. Thus there are two materials types used for this field investment such as thin film nitinol and stainless steel. Stainless-Steel type 316L are widely used in biomaterial bone applications specially fixing devices such as plates, screws, pins and artificial joints. On the other hands, thin film nitinol indicates a high possibility for applying in a small new vascular devices like heart valves and covering stent grafts because of the singular beneficial properties of this material like super-elasticity and low-profile feature.
Keywords: medial devise, biomaterials, implants, biocompatibility, 316L stainless steel and nitinol.

أستخدام مسحوق الهيدروكسي ابتايت في تغطية الفولاذ المقاوم للصدأ للاستخدامات الطبية (مراجعة)
نبأ ستار راضي
جامعة بابل/كلية هندسة المواد
الخلاصة:
حول العالم ملايين الاشخاص يستخدمون الاجزاء الطبية او المواد الحياتية كمزروعات داخل جسم الانسان او ستبدال الاجزاء للقيام بوظيفتها بدل الجزء المتضرر.الهدف الاساسي لهذه المزروعات هو الحفاظ على حياة الاشخاص او تحسين حياتهم معظم هذه الاجزاء تتلف بعد وقت قصير. السبب الاساسي لفشل المواد الطبية هو عدم التوافق الحياتي بين المزروعة والنسيج الحي. لهذا فان الفولاذ المقاوم للصدأ والسبائك الذكية (نيكل-تيتانيوم) المطليان بطبقة رقيقة هما الاكثر استخداما من بين المواد الحياتية. يستخدم الفولاذ المقاوم للصدأ نوع 316L بشكل واسع في تطبيقات العظام كأجزاء التثبيت على سبيل المثال البراغي والصفائح والاطراف الصناعية . من جانب اخر ان الطلاء على السبائك الذكية يعطي حرية في تطبقات القلب مثل الصمامات بسبب خواص هذه المواد المميزة مثل المرونه الفائقة.
الكلمات الساسية: المواد الحياتية، الاجزاء الطبية، المزروعات، التوافقية الحياتية، الفولاذ المقاوم للصدأ316L، السبائك الذكية (نيكل-تيتانيوم).
1. Introduction
The skeletal system, which is composed of bones, joints and teeth, have the ability to recover from a wide variety of injuries with minimal medical intervention. However, due to industrial environments, accidents of orthopedic produced much more complex types of injuries. In certain cases, orthopedic surgery is required to rebuild or to replace the damaged bone. Specifically, in the United States, more than 500000 joints are replaced yearly, with more than hundreds of thousands of people are being performed these operation worldwide (Langer and Vacanti, 1993) and total implants demand will be increased about thirty percentage during the next twenty years (Overgaard, et.al., 1992). In order to realize characteristics similar to the natural bone characteristics, it is important to imitative the natural bone composition and structure. Thus, having a look on the structure of the natural bone becomes important for achieving this purpose (Neville-Smith, et.al., 2000).
Moreover, according to (NOF, 2003) the osteoporosis patients numbers will be increased from (10.1 to 13.9) million between 2002 and 2020. In most cases, the use of these materials incorporates use of bone cements which are employed for fixing joints prosthesis. Bone cements work as a distributor for load on both the implants and the bone, also its filling bone and dental cavities by self-curing materials.
As well-known Steel suffering from corrosion in any severe environments and specially inside human body. So, Babu et. al ( 2004) try to make an improvement on bio-active coating of implants by using dip-coating method. The study was carried out by using Stainless-Steel type 316L as a substrate which coated by hydroxyapatite with biphasic calcium phosphate. At first, the substrate specimens were putting in a solution contains 20% of (HNO3) for fifteen minutes at (600?) in order to produce unreactive substrate surfaces. After that substrate specimens immerged in the solution to stat coating process. They have been found that, the using of this method with appropriate temperatures improves the bonding between the coating layer and the substrate. A little work has been found dealing the treating of metals thermally to reduce the corrosion. Many researchers try to using ceramics powder as an additive with coating solutions to produce ceramic layer on the metals.