Untitled

Abstract

Although titanium alloys are used in medicine, they present low wear resistance. In this paper we present the results of studies on surface layers produced by nitriding at three different temperatures, and by carbonitriding under glow discharge conditions in order to improve wear resistance, hardness, and to modulate microstructure and chemical composition of surface layers. A cell culture model using human fibroblasts was chosen to study the effect of such treatments on the cytocompatibility of these materials. The results showed that nitrided and carbonitrided surface layers were cytocompatible. Modulation of surface microstructure by temperature in the nitriding process and chemical composition of surface layers by carbonitriding led to differences in cellular behaviour. Cell proliferation appeared to be slightly reduced from the 6th day of culture on nitrided surfaces produced at 730 degrees C and 1000 degrees C, however after 12 days of culture, the best growth was on surface layers produced at 850 degrees C. The best viability was observed on the carbonitrided layer. The orientation and shape of the cells corresponded to surface topography. Nitriding and carbonitriding under glow discharge conditions may constitute interesting techniques allowing the formation of surface layers on parts with sophisticated shapes. They may also permit modulating surface topography in a way improving the features of titanium alloys for various applications in medicine.

The Importance Of Surface Topography For The Biological Properties Of Nitrided Diffusion Layers Produced On Ti6Al4V Titanium Alloy

“…Thus, by modifying the glow-discharge nitriding process, blood platelet adhesion and aggregation can be significantly reduced, which can be of great practical importance for the production of specificpurpose implants. This feature, in addition to the fact that nitrided layers on titanium and its alloys eliminate the metallosis effect and demonstrate a high resistance to wear by friction, as proven in previous studies [20], attests to the significant potential of this technology.…”

“…This proves that partial oxidation takes place on the surface layer of TiN as a result of plasma sterilisation. It is known as a fact that titanium oxynitrides and titanium oxide (TiO 2 ) demonstrate good biological properties [11,20]. The phase composition of the surface has been shown to be the same for all the tested nitrided layers, which allow us to conclude that the micro-and nano-roughness of the TiN surface, i.e.…”

“…These features affect such functional properties as hardness, wear resistance, mechanical properties, biological properties and wettability. In order to modify the properties of biomaterials, different methods of surface treatment are used, ranging from electrochemical oxidation, thermal spraying, ion implantation, laser treatment (PLD), chemical vapour deposition (RFCVD, MWCVD), to hybrid and glow-discharge methods [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. Selection of the appropriate method depends on the final application of the material, the implant's shape and the expected characteristics of the produced surface layers.…”

“…The surface layers formed are diffusive in nature and can be produced on complexly-shaped parts. They also possess titanium nitride (TiN) in the external zone, which is characterised by good biocompatibility and resistance to wear by friction [8,16,19,20]. Depending on the structure and surface topography of the layer, its biological properties, such as haemocompatibility, can be modified.…”

Surface Modification Of Implants For Bone Surgery

“…New implant surface modification technologies have recently been implemented to ensure highly favourable physicochemical properties and biocompatibility with the cardiovascular system. Worth mentioning are, plasma oxynitriding or nitriding and nitriding or carbonitriding accomplished through pulsed laser deposition [18,19]. Glow discharge technologies, based on both, plasma and cathode potential, ensure surface layers of diffusive character with the outer zone of nanocrystalline TiN, or TiO 2 .…”