Zirconium dioxide

also “Zirconia ZrO2
physical Density 5,68 g/cm³
Medical used Zirconium dioxides usually come with some dopants, which clearly improve physical properties
chemical The change of volume caused by the structure transitions from tetragonal to monoclinic to cubic induces large stresses, causing it to crack upon cooling from high temperatures. When the zirconia is blended with some other oxides, the tetragonal and/or cubic phases are stabilized. Effective dopants include magnesium oxide (MgO), yttrium oxide (Y2O3, yttria), calcium oxide (CaO), and cerium(III) oxide (Ce2O3).
applications The main use of zirconia is in the production of ceramics,  other uses including as a protective coating on particles of titanium dioxide pigments, as a refractory material, in insulation, abrasives and enamels. Stabilized zirconia is used in oxygen sensors and fuel cell membranes because it has the ability to allow oxygen ions to move freely through the crystal structure at high temperatures. This high ionic conductivity (and a low electronic conductivity) makes it one of the most useful electroceramics.
medical applications Zirconium dioxide ist used in dental technology for ceramic tooth restorations. It is used for dental implants, balls and sockets of joints.
biocompatibility Biocompatibility of Zirkonium dioxide has been proven manyfold.
adverse effects Adverse effects are described in animal trials on nanoparticles of Zirconia dioxide. There is no significance of adverse effects shown yet in clinical use.
Surface characteristics and coatings are in development.