Fired magnesium oxide stabilized transformation toughened zirconia ceramic can be for or of an implant or implant component of a one-piece unicompartmental knee spacer device; a multi-piece unicompartmental joint aligning device; a temporal mandibular joint cap implant; a vertebra cap; an ankle joint ensemble or component; a bridge, a tooth or teeth; a patellofemoral joint implant; a tibial tray for a knee joint replacement implant; an intermediary articulation plate for a tibial tray and liner for a knee joint replacement implant; or the intermediary articulation plate assembled in combination with the tibial tray.