Preparation and characterization of porous alumina ceramics for bone implants

Abstract

The bioceramics inert, such as alumina, are mainly used in replacement of bones, hip prostheses and dental implants because their mechanical properties and resistance to corrosion, chemical purity and biocompatibility, showing little or no chemical change during the period of exposure to physiological environment. By being a material bioinert, several studies have been carried out aiming at obtaining new alternatives to make the biological performance of these ceramics more appropriate. One of the alternatives is the coating biomimetic in solutions with concentrations equal to those of human blood plasma, which leads to the development of a bioactive layer, consisting of carbonated hydroxyapatite crystals of low crystallinity on the surface of the implants. The hydroxyapatite stands out among the other apatites as bone grafts by be a bioactive material, and be the main mineral constituent of bone matrix. It is of extreme importance that the device to be deploying possesses pores interconnected for the development and fixation of the tissue inside the implants. For obtaining such porous material is necessary to take into account the geometry of the part to be produced, and also the characteristics of the pore structure that if you want to. The technique to be used in this study to obtain the ceramic matrix of alumina is the method of replica or polymeric sponge with the objective of obtaining pores interconnected to increase the permeability of fluids and gases through the structure. The porous alumina will be coated with hydroxyapatite by biomimetic method that allows the coating of the substrate with a uniform layer of hydroxyapatite. The physical characterizations, microstructural and mechanical systems will allow them to assess the characteristics of these biomaterials aiming to contribute to the development of the manufacture of bone substitutes with the best properties in the area of orthopedics, maxillofacial surgery and dentistry. (AU)