Inherently Fluorescent Esthetic Full-Contour Zirconia

Objectives: Recently, monolithic zirconia has made big steps toward becoming a highly esthetic restorative material by significant improvements in translucency. One other important feature is inherent fluorescence that matches that of natural dentin. While fluorescence for zirconia is already available for some materials in light tooth shades, it will be shown that this feature now has become available for all tooth shades.
Methods: Specimens (1mm thickness) were obtained by slicing dental materials (from 3M: Lava™ Esthetic A1, A3.5 cut from the body section and Lava™ Plus shaded by immersion in Lava™ Plus Dyeing Liquids A1, A3.5 in combination with Lava™ Plus Effect Shade Fluorescence; from Kuraray Noritake: Katana™ STML A1 cut from the body section; from Ivoclar Vivadent: IPS e.max® CAD LT A1). Zirconia specimens were fired to full density, glass-ceramic specimens were crystallized according to IFU. The color of the obtained samples was measured, irradiating with artificial daylight with and without UV component, using a Color i7 from X-Rite. Fluorescence spectra were obtained by subtraction of spectra measured without UV from spectra measured with UV. As fluorescent reference material, bovine dentin was used.
Results: The Lava™ Esthetic samples show a broad fluorescence spectrum with a maximum at about 450nm (blue) that is very similar to the spectrum of bovine dentin. The glass-ceramic sample shows fluorescence with a peak at 550nm (green/yellow) (Fig.1). The fluorescence intensity decreases with darker shades. Lava™ Esthetic constantly shows a higher fluorescence than Lava™ Plus (Fig.2).
Conclusions: Lava™ Esthetic shows strong, dentin-like fluorescence even in combination with dark shades like A3.5. Lava™ Plus is noticeably fluorescent only when light shades like A1 are applied. The Katana™ sample is not fluorescent. IPS e.max® CAD shows fluorescence, but the fluorescence color deviates from that of natural dentin.