Functionally graded dental implants by SPS

Titanium and its alloys are the most commonly used materials for dental implants. Although the biological performance of these alloys are extremely good, there are potential immunologic and aesthetic issues with titanium implants. The material currently explored to replace titanium alloys is yttria-stabilized zirconia (YSZ) due to its tooth-like colour, hardness, toughness, corrosion resistance and osseointegration. However, the lack of long-term stability of YSZ in presence of body fluid is a major disadvantage. To achieve the benefits of each of these materials and nullify their drawbacks, functionally graded materials (FGM) of Ti-alloy/zirconia, was developed using the spark plasma sintering (SPS) process. Their physical and mechanical properties, microstructure analysis and in-vitro biocompatibility tests were carried out and compared with existing commercial implants. The Ti-alloy/zirconia bi-layered component yielded excellent mechanical properties like strength, hardness and in-vitro biological properties like cytotoxicity, hemolysis and cell proliferation at par with those of commercially available dental implants.