Zirconia is a bioceramic material widely used for dental implants. In this work, the sinterability of nano-crystalline powders has been investigated by dilatometry in the temperature range of 1250 to 1400 0C with isothermal holding times of up to 8h. A slight increase in grain growth and an increasing linear shrinkage have been observed with increasing sintering temperatures. The sintered samples were submitted to Vickers' hardness and KIC tests and the results compared regarding the sintering conditions. It has been verified that satisfactory hardness and fractures toughness have been achieved after sintering above 1300 0C during 8h.