Ceramic coatings with variable composition and bioactivity, intended for biomedical applications in prostheses and implants

The invention refers to a process for obtaining bioactive ceramic coatings containing two or more compounds distributed in consecutive layers, or in layers of variable composition depending on the thickness or on the surface distribution, intended for application in biomaterials useful in internal prostheses or orthopedic surgery implants, dental implants or dentures, facial- maxillary reconstruction, ear, nose and throat, or oncological surgery implants or prostheses. The invention refers to the methods of obtaining and production of coatings of bioactive ceramic matrix intended for applications in biomaterials, characterised in that they present variable bioactivity. They are based on compounds of apatite type, in particular, hydroxy apatite of chemical formula Ca10(PO4)6(OH)2, or Ca5(PO4)3(OH), or fluoroapatite of chemical formula Ca10(PO4)6F2, or Ca5(PO4)3F, or hydroxy apatite modified by partial substitution of the radical, OH by the ion F, or of the ion Ca2+ by the ions Mg2+, Fe2+, Na+ and K+, and whose composition in other phases, primarily calcium phosphates, tricalcium phosphate or tetracalcium phosphate, or bioactive glasses of the system P2O5-CaO, with possible additions of Na2O, K2O, CaF2, MgO, SiO2 and Al2O3, modify the bioactivity and/or their mechanical characteristics relative to the ceramic matrix. As a result of these modifications, the reactivity kinetics of these coatings relative to the surrounding physiological environment, after implantation in the host organism, is increased in the outermost regions of the coating, thereby accelerating the respective dissolution, as compared to the dissolution capacity present in the more interior regions of the same coating, which are in contact with the base material or substrate. The materials comprising the substrate can be metal, composite, bioinert ceramic, or polymer. The process of obtaining the coatings may vary, it being possible to employ one or more of the following techniques, including cathodic pulverisation, or a method of formation in liquid medium by electrochemical means, or electrophoresis or pulverisation by flame, by arc, by plasma or by detonation, vapour-phase or arc-induced or laser-fusion deposition, or a process of painting with drying and burning, or also by enamelling or vitrification, and the total thicknesses of the coating may vary between 1 and 300 u, while the thickness of the various layers in the case of multiple-layer coatings, may be of any compatible thickness w