Masking Tetracycline Stained Teeth: Effect of Translucency and Thickness of Multiple CAD-CAM Masking Tetracycline Stained Teeth: Effect of Translucency and Thickness of Multiple CAD-CAM Veneer Materials and Shades of Resin Cements

Abstract This study aimed to assess the masking potential of different CAD-CAM veneer restorations to restore tetracycline-stained teeth. One-hundred-eight CAD-CAM ceramic discs, shade 1M1, with high (HT) and low (LT) translucencies and 1mm and 0.7mm thicknesses were prepared from three CAD-CAM materials (IPS-e.max-CAD (EMC), VITA Enamic (VE) and Vita Suprinity (VS)). Resin cements, shades A1, white opaque (WO) and translucent (T), were used for cementation against a dark base. Color differences (ΔE*) between the restorations (veneer/resin cement/dark base) and a standard 1M1 shade-guide-tab were calculated. Mann-Whitney-U and Wilcoxon-signed-rank tests; and one-way ANOVA, Kruskal-Wallis and Bonferroni-post-hoc tests were used to compare between two and three groups respectively (P ≤0.05). Groups EMC-LT-0.7-T, VE-LT-1-A1 and VE-LT-1-T rendered restorations with ΔE* below the perceptibility threshold (<1.74), while EMC-LT-0.7-A1 and all LT-0.7mm VE restorations were within the acceptability threshold (<3.48). VS had significantly higher (ΔE*) compared to of EMC and VE materials. Ceramic thicknesses had no significant effect on (ΔE*), while the effect of translucency level of the ceramics and the shade of resin cement was significant. It was concluded that low translucency ceramic veneers can better mask darkly stained teeth, irrespective of their thicknesses, with resin cements shades affecting the color of the final restorations.