Microstructure, mechanical properties, friction and wear performance, and cytotoxicity of additively manufactured zirconia-toughened alumina for dental applications

Zirconia-toughened alumina (ZTA) ceramic has potential dental restoration and repair applications due to its high mechanical strength, toughness, wear resistance, chemical durability, and biocompatibility. Nevertheless, there is a great deal of crack initiation caused by stress accumulation and also material wastage after computer-aided design/computer-aided manufacturing of ZTA ceramics in conventional clinical processing. In this study, we prepared a ZTA green compact using Stereolithography (SLA) technology followed by sintering at high temperatures ranging between 1450 degrees C and 1650 degrees C. The microstructures, mechanical properties, friction and wear performance, and cytotoxicity of the ZTA ceramic were investigated. The results indicate that all ZTA samples were composed of alpha-Al2O3, m-ZrO2, and t-ZrO2 phases before and after sintering. With increasing sin-tering temperatures from 1450 degrees C to 1650 degrees C, the density, mechanical properties, hardness, and wear perfor-mance of the ZTA samples were gradually improved. The ZTA sample sintered at 1650 degrees C with a relative density of 96.65% showed the best mechanical performance, with a flexural strength of 572.0 MPa, a Vickers hardness of 16.2 GPa, and a fracture toughness of 7.4 MPa m1/2. The sintered ZTA sample exhibited a good cell viability toward MC3T3-E1 cells.