Effects of Aging on the Mechanical Properties of Dental Pigmented 3Y-TZP Ceramics

摘要

The purpose of this study was to investigate the structure,mechanical and low temperature aging properties of colored dental zirconia ceramics. Colored 3Y-TZP zirconia dental zirconia ceramics were made by mixing colorants and their combinations into a 3Y-TZP powder,the green body were compacted at 200MPa,presinter at 1050℃ and densely sintered at 1500℃ for 2h. Specimens were subjected to an accelerated aging test carried out in an autoclave in steam at 134℃, 2bar,for 4hs. XRD was used to identify the crystal phases,three-point bending strength were tested before and after aging according to the ISO 6872 standard,polished and aging specimens were observed by Atomic Force Microscopy (AFM) to evaluate surface microstructure. Tetragonal-to-monoclinic phase transformation was detected for both uncolored and colored specimens,the relative content of monoclinic phase was increased with the prolonged aging time. Aging had no significant negative effects on flexural strength on colored 3Y-TZP. The nucleation and growth of monoclinic phase were detected by AFM in surface of both colored and uncolored zirconia.