Preparation and biological evaluation of ZrO2 all-ceramic teeth by DLP technology

Personalized zirconium dioxide (ZrO2) all-ceramic teeth are expected to be widely used in the field of oral restoration. Here, ZrO2 all-ceramic teeth were fabricated for biological engineering by photosensitive resin based digital light processing (DLP) technology. When sintered at 1500 °C for 3 h, dense ZrO2 ceramics were obtained with relative density of 98.02 ± 0.32%, Vickers hardness of 12.62 ± 0.15 GPa and fracture toughness of 6.11 ± 0.36 MPa∙m1/2, which were close to those of the ZrO2 ceramics prepared by dry pressing. To confirm whether the prepared ZrO2 ceramics possessed good biosafety, in vitro biological experiments were further performed with rat bone marrow mesenchymal stem cells (rBMSCs) and preferable cell attachment was observed at the initial stages. Results illustrated that the compositions with cytotoxicity in green samples were completely decomposed after debinding and sintering process, and the ZrO2 ceramics could provide an ideal biocompatible environment for mesenchymal stem cells. This study shows that ZrO2 all-ceramic teeth with personalized structure prepared by DLP technology have good mechanical properties and biocompatibility, exhibiting strong potential in the field of oral restoration.