EFFECT OF TIME OF IMMERSION ON THE CORROSION OF STAINLESS STEEL IN PHYSIOLOGICAL MEDIUM

ABSTRACT This work was devised to tow parties. In the first, we studied the effect of time of implantation on the surface corrosion of stainless steel (StSt) using electrochemical methods (free potential, polarisation curves, electrochemical impedance spectroscopy (EIS)) and scanning electron microscopy (SEM). There was no evidence of corrosion on visual inspection in any of the implanted intramedullary nails but the examination of the surface by SEM shown overall corrosive changes; this corrosion was most observed when the period of implantation was increased. In the second party, the inhibition behavior of these specimens in the presence of Eugenol (2-methoxy 4-allyl phenol) was investigated. KEYWORDS : Corrosion; Implantation; Stainless steel; Electrochemical methods; SEM INTRODUCTION Various studies have shown that some metallic components of the alloys used in orthopedics are toxic and dissolve in body fluids due to corrosion [1]. The corrosion resistance of the alloy and the toxicity of individual metals in the alloy are the main factors determining biocompatibility. The physical properties of the metal surface and the microparticles that dissolve from it also have an important role [2-4]. In order for these materials to perform successfully, they must have physical properties that allow the material to perform the function for which it was implanted, and the material must be biocompatible. In order for a material to be biocompatible, it must not adversely affect the physiological environment should not have detrimental affects on the material. Any time a foreign material is placed inside the human body; there are many causes that contribute to the corrosion of metals [5-11]. The applicability of organic compounds as corrosion inhibitors for metals has been recognized for a long time. The existing data show that most organic inhibitors act by adsorption on the metal surface. Generally, the tendency to form a stronger coordination bond and, as consequence, inhibition efficiency should increase in the order O< N< S< P [12]. Eugenol (Figure1) occurs widely as a component of essential oils and is a major constituent of clove oil. It has been used since at least the nineteenth century, primarily as a flavoring agent, in a variety of foods and pharmaceutical products, and as an analgesic in dental materials. Recently it has been used as inhibitor on the corrosion of stainless steel in phosphoric acid solution [13]. In this order, many studies realised in our laboratory through electrochemical methods (electrochemical impedance spectroscopy, Free potential, potentiodynamic polarization curves) have