Objective: Structural ceramics based on tetragonal zirconia has been used in dentistry with the goal of building prosthetics infrastructures, starting from the machining of prefabricated blocks. However, it is known that this material can undergo aging in humid conditions, thus allowing them to revert to the monoclinic phase, potentially compromising their mechanical properties. The type and amount of stabilizing ions but also the morphology, the particle size distribution, and the structural characteristics of the powders are directly related to this phenomenon. Method: in this work different stabilizing ions (Ce and Y) have been tested to obtain nanosized tetragonal zirconia powders by Pechini (citrate) route. The obtained powders have been characterized in order to evaluate the effect of cerium and yttrium on their sinterability and mechanical properties. The powder characterization shows that the chosen synthesis method allows to obtain nanometric powders of tetragonal zirconia (P42/nmc) through the formation of solid solutions. Defined the optimal sinterization conditions choosing a two step sintering in order to obtain a nanostructured materials, aging test (134°C per 10 hrs in hydrothermal conditions) have been performed on the obtained samples to evaluate the low temperature degradation of zirconia due to the tetragonal-to monoclinic transformation. Result: After aging XRD confirms the presence in both powders of tetragonal solid solutions as main crystallographic phase Conclusion: taking into account that in literature aging at 134°C for 1 hrs is theoretically similar to 3-4 years in vivo, we can conclude that the synthesized powder have a good stability against Low Temperature Degradation (LTD).