Fabrication of ZTA crowns with simultaneously improved isotropy on mechanical property and surface quality by DLP

Abstract

Zirconia‐toughened alumina (ZTA) composite ceramics show great potential for use in dental repair applications due to their unique properties. Complex‐shaped ZTA all‐porcelain crowns can be accurately fabricated using digital light processing (DLP) technology. However, effectively controlling both the anisotropy on mechanical property and surface quality of ZTA composites shaped by DLP remains a critical challenge that requires further research and innovation. In this work, we propose an efficient method to synchronously enhance the isotropy on mechanical performance and surface quality of DLP formed ZTA all‐porcelain crowns by controlling contents of yttria‐stabilized zirconia (YSZ) powders. When enhancing contents of YSZ from 5 to 20 wt%, multilayer microstructure with obvious interlayer gaps transformed into uniform microstructure with strong interlayer bonding, and the smaller alumina grain was observed on the stair‐stepping microstructure. Finally, the ZTA composites exhibited flexural and comprehensive strength as high as 640.3 and 6.9 MPa, and dimensional precision as low as 37.5 and 43.5 μm on top and side surface, together with simultaneously enhanced isotropy on mechanical property and surface quality, well satisfying the demands for all‐porcelain crowns fabricating. This study provides thorough understandings on isotropy regulating of DLP‐shaped ZTA all‐porcelain crowns with excellent mechanical performance and surface quality.