An alumoxide ceramic implant doped with magnesium oxide is developed and its structure and physicochemical and mechanical properties are examined. Medicobiologic investigations of the implant are also carried out. The implant Alumag-1 is recommended for clinical testing.At present, different polymeric, ceramic, and metal materials are used in medical practice as substitutes for organs or their fragments.Ceramic materials are widely used in home and foreign orthopedic and stomatologic practice, because of their corrosion resistance, high chemical stability, and good compatibility with biological tissues; moreover, the elastic moduli of ceramics and bone are similar. The composition of the "Bioceram" alumina ceramics applied abroad is close to pure 99.7% A1203 doped with 0.1~0.2% MgO. It is produced under high pressure and temperature (1800~ [1]. As early as 1960s, alumina ceramics was used in orthopedics by scientists in Tbilisi [2]. Similar work was later performed in Ukraine, Moscow, St. Petersburg, etc. [3]. A particular requirement for the material is a combination of strength and porosity, and in addition it should possess good technological properties suitable for manufacturing implants of complex geometrical shape.In the present study, as a result of the investigations performed, the method of obtaining ceramic implants was developed, the effect of dispersion of the initial powders and the temperature of their thermal treatment on the physicomechanical properties of the materials was examined, and medicobiologic tests were carried out.
Experimental ProcedureTo obtain alumoxide ceramics, A1203 fibers doped with MgO were used as the initial material. The latter were chosen for their high chemical stability, porosity, developed surface, and the ability to form upon sintering both dense and porous ceramic materials. Oxide fibers were synthesized according to the method described in [4]. As the base polymer we used hydrate cellulose filaments or nonwoven needle-punching material (of felt type}, which were carefully cleaned of technological impurities and impregnated with a solution of aluminum and magnesium chloride with the ratio of components 99.5 and 0.5 tool.% in terms of metal oxides.After drying, the fibers were thermally treated in a special regime up to 600-1000~ Then the fibers were ground, and the preforms prepared were sintered at 1600~ The structure of the materials was investigated by methods of infrared spectroscopy, scanning electronic microscopy, and X-ray phase analysis. The density, porosity, hardness, and strength of the ceramic materials obtained were determined by standard methods, whereas the specific surface was found via the BET method from the curves of sorption--desorptionof benzene vapors by a porous material under the standard conditions.