Influence of Opacifiers and Different Dentin Thicknesses on the Optical Properties of a Darkened Teeth with Limited Sound Tissue Reduction

OBJECTIVE: To evaluate color masking and relative translucency parameter (RTP) of increasing dentin thicknesses from different resin composites, with or without opacifiers, on a veneer dental preparation and resin disks. MATERIAL AND METHODS: Artificial darkened lateral incisors with 1mm-thick veneers preparations were used to evaluate color masking of different resinous materials, with or without opacifiers: IPS Empress Direct (ED) with or without ED Opaque; and Essentia (ES) with or without ES Masking Liner. For the RTP test; disc-shaped specimens were performed and evaluated with a spectrophotometer (VITA Easyshade) against black and C4 backgrounds. Color differences were calculated using the CIEDE2000 formula (ΔE00). RESULTS: The dentin layer thickness presented no influence on the ΔE00 (P>.05) of the ED group with opacifier; without opacifier, 0.3mm dentin thickness presented higher ΔE00 than 0.8mm layer (P=0.000). For ES group, with and without opacifier, there was a significant decrease in ΔE00 with the increase of dentin thickness (P