The development and characterization of biocompatible zirconia medical ceramics

Biocompatible materials are materials that support organs or tissues of human body to accomplish their functions. Zirconia ceramics (ZrO2) are called 'ceramic steel' due to its high mechanical, chemical and physical features. And also, these materials are used in many fields including dental implemantations. 3-5% volume change occurs during tetragonal-monoclinic phase transformation of zirconia and it is original characteristic behavior. Oxides of rare earth and alkaline earth elements such as calcium oxide (CaO), yttrium oxide (Y2O3), magnesium oxide (MgO), cerium oxide (CeO) are used to keep zirconia stable in room temperature, Highly hardness tetragonal zirconia polycrystalline (Y-TZP), which is used especially in dentistry and many different fields, is obtained from adding Y2O3 into pure Zirconia. High fracture toughness of CeO2-TZP, stabilized with similarly obtained cerium, is known. Mixtures containing Y-TZP ve Ce-TZP prepared in different compositions and shaped by dry pressing and cold isostatic pressing (CIP). Shaped samples sintered by using 1500 and 1550 oC sintering temperature and 1-2 hours sintering duration. Water absorption rate, bulk density, theoretical density and apparent porosity rate of sintered samples calculated. Besides, the change in features related to sintering temperature and sintering duration of samples, which mechanical features such as Vickers hardness and fracture toughness determinated, have been interpreted.