[Effect of sintering temperature on mechanical properties of dental zirconia toughened alumina ceramics].

PURPOSE: To investigate the effect of sintering temperature on mechanical properties of dental zirconia toughened alumina (ZTA) ceramics prepared by gel-casting technique.

METHODS: The samples prepared by gel-casting were sintered at 1100, 1200, 1250, 1300 and 1400degrees centigrade for each group. The flexural strength, fracture toughness, Vickers hardness and brittleness index were obtained and microscopic morphology of each group was observed under scanning electron microscope (SEM). The data were statistically analyzed using SPSS 19.0 software package.

RESULTS: The flexural strength, fracture toughness and Vickers hardness increased with the increasing sintering temperature during 1100~1400degrees centigrade. The lowest brittleness index (0.74±0.16) μm-1/2 was observed in group sintered at 1200degrees centigrade and the highest (2.76±0.14) μm-1/2 was at 1400degrees centigrade (P<0.05), while the flexural strength of these two groups was (46.89±3.24) MPa and (349.64±54.72) MPa, respectively.

CONCLUSIONS: The ZTA dental ceramics exhibit good machinability with proper sintering temperature (1200degrees centigrade) and the strength meets the requirement of clinical application.