Plasma modification of medical implants by carbon coatings depositions

Purpose: The main goal was to work out the technology of deposition of carbon layers onto surface of medical implants made of the AISI316L medical steel. So far the results of carried investigations have proved that layers synthesized in RF PACVD process noticeably improve the biotolerance of the medical steel. Positive experimental results concerning the implementation of carbon layers conducted in the Institute of Materials Science and Engineering of the Technical University of Lodz were the basis for attempt of industrial application of the worked out technology. Design/methodology/approach: Carbon layers were manufactured using radio frequency plasma RF PACVD method. The technology was worked out for the surfaces of the intramedullary nails. The investigations were carried out in order to compare obtained synthesis results with the layers deposited under the laboratory conditions. In this work the following are presented: the surface topography investigation, results of nanohardness and adhesion measurements as well as the raman spectra. Medical examination results were presented in our earlier publications. In the description of obtained investigation results are also presented the preliminary results of the medical treatment effects with the use of intramedullary nails covered with the carbon layer. Findings: Carbon layers manufactured onto intramedullary nails presented good mechanical properties. Applied synthesis parameters made it possible to manufacture uniform film onto whole implant surface. Thickness of the layer was varied in the range of 200 – 400 nm, however total modification area contained 3.5 micrometers. Nails covered with the carbon layer positively passed the tests and were admitted into medical trade turnover. Positive medical treatment results were observed especially in case of patients with affirmed allergies onto alloying components contained in medical steels like chromium and nickel. Research limitations/implications: Significant matter for the examinations had the introduction of the additional control parameters of the plasmo-chemical layers synthesis process. From the point of view of the industrial implementation of technology the fact of limited process efficiency can be. Originality/value: The fundamental value of conducted investigations is the industrial application of the technology of deposition of carbon layers onto intramedullary nails. Currently those products are available in the business offer of MEDGAL Company.