ABSTRACT
Fig. 5 shows average OD values for the ALP of individually injected and printed samples after incubation for different time periods. As shown in Fig. 5, no obvious difference in OD values was observed after incubation for one day. After a 4-day incubation period, OD values of various samples remarkably increased and the Fs-1 sample had the highest ALP content. After 7-day and 10-day incubations, the Fs-1 sample also had the highest OD value and exhibited a significant difference at D4 (p < 0.05), D7 (p < 0.05), and D10 (p < 0.05) when compared with the untreated sample. The Fs-2 and Fs-3 samples displayed no obvious change or significant difference. Cell adhesion was further observed and the results are shown in Fig. 6. The cell growth status was observed at D4, and cells on the surfaces of four samples were adherent with pseudopodia, extending and attaching to the surface of the
samples, indicating that the cells proliferated and started accumulating. Due to the presence of rough and porous surfaces, the Fs-1 sample exhibited sphere-like cell adhesion, whereas other samples displayed rod-shaped cell morphology. This phenomenon was also observed in samples after day-7 and day-10 incubations. This result proves that after being injected and printed from the mold and treated under different parameters, the samples did not release toxic substances into the cells and exhibited excellent biocompatibility. Therefore, zirconia printed by using this method has great potential to be used in artificial gums in future.
