Comprehensive Properties Evaluation of Fluorescent Zirconia

Objectives: Two kinds of multi-layer fluorescent zirconia (FGTE-Pro A1 supported by Upcera, and LAVA Esthetic A1 from 3M) were comprehensively evaluated, including 3-point flexural strength, Vickers hardness, coefficient of thermal expansion (CTE), aging properties, Translucent parameters (TP), fluorescence and color stability.
Methods: 3-point flexural strength and coefficient of thermal expansion (CTE) were measured according to ISO 6872-2024. Vickers hardness was measured according to ISO 14705-2021. Translucent parameters (TP) was measured and calculated using a desktop spectrophotometer. Fluorescence intensity and luminescence spectrum was measured with fluorescence spectrophotometer. Color different(△E) was tested before and after glazing treatment to check the color stability. Low temperature degradation performance was tested in the vapour of 134°C for 5h. and the microstructure and phase composition was analyzed by SEM and XRD.
Results: From fluorescence CIE coordinates, blue-white fluorescence effect can be observed at excitation wavelengths of both 365nm and 395nm for LAVA Esthetic and FGTE-pro, FGTE-pro has higher fluorescence intensity than LAVA Esthetic. The TP and of incisal part of FGTE-pro is 8.67 higher than LAVA Esthetic with 8.54. The 3-point strength of body part of FGTE-pro is over 844.6 MPa compared with LAVA Esthetic with 603.4 MPa. SEM images show the microstructure of tetragonal phase and cubic phase with uniform distribution. After hydrothermal aging, the monoclinic phase content of FGTE-pro and LAVA Esthetic is less than 1%. The hardness of the two materials is between 10.7-12.0GPa, and the CTE of two materials is between 10-11×10-6/K. The △E of FGTE-Pro and LAVA Esthetic before and after glazing are respectively 0.83 and 1.5.
Conclusions: Both materials are suitable for dental applications, comparing with conventional zirconia, they provide better simulation effects under special light sources, more suitable for 1-3units anterior esthetics restorations.