Experimental study of the effect of CAD/CAM ceramic–luting resin combinations on fluorescence under different light sources

Abstract

Objective: To evaluate the compensatory effect of a luting resin on the fluorescence of different CAD/CAM ceramics at various thicknesses under excitation wavelengths of 365 nm and 405 nm.

Methods: Specimens of IPS Empress CAD Multi, IPS e.max CAD HT, MT and LT, and Vezneer HV were fabricated with thicknesses of 0.4, 0.6, and 0.8 mm (n = 15). A recently extracted human maxillary central incisor was used as a reference. Samples were evaluated under 365 nm ultraviolet light and 405 nm violet LED illumination, with and without a luting resin (Variolink Esthetic Light+). Standardized photographic records were collected for visual analysis.

Results: Under 365 nm excitation, IPS Empress CAD Multi showed the closest fluorescence match to the natural tooth, followed by IPS e.max CAD MT. Under 405 nm excitation, all materials exhibited a marked reduction in fluorescence. The hyperfluorescence of the luting resin produced a slight overall compensatory effect, with the leucite-based ceramic group showing the best performance; however, fluorescence levels comparable to those of the natural tooth were not achieved.

Conclusions: The fluorescent response of CAD/CAM ceramic–luting resin combinations, regardless of material and thickness, was insufficient under 405 nm LED illumination compared to the natural tooth.