Dense alumina toughened zirconia nanocomposites (ATZ, 3Y-TZP with 20 wt% Al2O3) were densified by non-conventional microwave sintering technology at relatively low temperatures (1200 and 1300 °C). The sintering method and its effect on densification, microstructure, mechanical properties and tribological behaviour were investigated. The outcomes demonstrated that the density rose as the sintering temperature was higher, and therefore the mechanical properties were enhanced, reaching a maximum hardness (18.4 ± 0.4 GPa) and fracture toughness (5.7 ± 0.3MPa· m1/2). In addition, the samples were subjected to a tribological test in dry and wet conditions, using artificial saliva. In both cases, the coefficient of friction and wear volume for samples obtained by microwave sintering are lower than conventional samples, with the wear volume being two times higher in dry conditions than in wet conditions.