**Abstract**

Ceramics are increasingly used as structural materials with biomedical applications due to their mechanical properties, biocompatibility, esthetic characteristics and durability. Specifically, zirconia-based compounds are commonly used to develop metal-free restorations and dental implants. The consolidation of ceramics is usually carried out through powders by means of processes that require a lot of energy, as long as processing times and high temperatures (over 1400°C) are required. In the recent years, new research is being developed in this field to reduce both energy consumption and processing time of ceramic powders. One of the most promising techniques for sintering ceramics is microwave heating technology. The main objective of this chapter is to obtain highly densified zirconia-alumina compounds by microwave technology. After sintering, the materials are characterized to determine whether the final properties meet the mechanical requirements for their final applications as dental material. Finally, the characterization of specimens treated by low-temperature degradation (LTD) is carried out after each 20 h of LTD exposure up to 200 h. In addition, the quantification of monoclinic phase by micro-Raman spectroscopy, analysis by AFM and Nomarski optical microscopy and assessment of the roughness and mechanical properties (hardness and Young's modulus) by nanoindentation technique have been studied.

**Keywords:** zirconia-alumina, microwave sintering, bioceramics, mechanical properties, hydrothermal degradation
