INFLUENCE OF SPARK PLASMA SINTERING CONDITIONS ON Si3N4 CERAMICS USED FOR BONE IMPLANTS

Silicon nitride attracts the attention of many researchers for its use in orthopedic and dental applications, but is not yet established as a biomaterial, the research is ongoing. Present paper deals with the obtaining of Si3N4 ceramics unconventional heat treatment (spark plasma sintering. The sintering process was pursued through the variation of four Influencing parameters: sintering temperature, the heating rate, the pressure applied during sintering and soaking time. The obtained ceramics were characterized using X-ray diffraction for the phases determination and scanning electron microscopy for microstructure characterization. Also, were determined ceramic and mechanical properties. By testing the biocompatibility of these ceramics in contact with the physiological environment by following the evolution of pH and ionic conductivity on immersion of ceramics in SBF is found that pH values and ionic conductivity samples varies widely In the first days but after stabilizes around SBF values. Regarding the antibacterial effect, the tests indicate a triple value of biofilm inhibition area for the Si3N4 samples, as comparing with pure titanium, measured under the same condition. Also, was evaluated the MG-63 cell proliferation (by lactate dehydrogenase method - LDH) and morphology.