Metal ion release from metal implants

In surgical disciplines where bone has to be repaired, augmented or improved, bone substitutes are essential. Although bone banks, such as Eurotransplant, are founded to supply such substitutes, natural bone is not always adequate. For example, frequently these so-called bone grafts resorb after implantation (1). Further, they cannot be used for joint and tooth replacement, and recently worries have been raised about the transfer of infectious diseases. Therefore, interest has dramatically increased in the use of synthetic materials for replacement of lost or damaged bone tissue. The generic name of these tissue alternatives is biomaterials. A special class of these biomaterials is composed of metallic devices with coatings to improve bone bonding. These specialized coatings used to improve the metallic implant are the topic of this paper.

http://journals.sagepub.com/doi/pdf/10.1243/0954411981533917

Thin Calcium Phosphate Coatings for Medical Implants

Nucleation and growth of calcium phosphate on amine, carboxyl- and hydroxyl-silane self-assembled monolayers

This chapter covers information on the composition, microstructure and physico-chemical properties of thin oxide films on titanium and titanium alloys. The focus is on thin layers in the sense of ‘natural’ oxide films grown at ambient or higher temperatures with emphasis on titanium oxide, with some selected additional information on oxides related to metals commonly used as alloying elements in titanium alloys for biomedical applications. This chapter does not, however, include thicker oxide films such as those produced by electrochemical or plasma techniques, which are covered in Chap. 8.

Properties and Biological Significance of Natural Oxide Films on Titanium and Its Alloys

Metals, in addition to ceramics and polymers, are important class of materials considered for replacement of non-functional parts in the body. Stainless steel 316, titanium and titanium alloys, Co-Cr, and nitinol shape memory alloys are the most frequently used metallic materials. These alloys are prone to corrosion in various extents. This review briefly discusses the important biomaterials, their properties, and the physiological environment to which these materials are exposed. Corrosion performance of currently used metallic materials has been assessed and threat to the biocompatibility from corrosion products/metal ions is discussed. The possible preventive measures to improve corrosion resistance by surface modification and to increase the bioactivity of the metallic surfaces have also been discussed. Importance of the formation of oxide layers on the metal surface, another aspect of corrosion process, has been correlated with the host response. The gap areas and future direction of research are also outlined in the paper.

M. Ota

Papers

Characterization of surface film formed on titanium in electrolyte using XPS