Masking ability of indirect restorative systems on tooth-colored resin substrates

Objective. To evaluate the masking ability of different indirect restorative systems (IRS) on tooth-colored resin substrates. Methods. A1-shaded specimens from 5 IRS (LDC-IPS e.max (R) CAD; YZW-Zenostar Zr Translucent; PICN-Enamic; YLD-T-IPS e.max (R) ZirCAD + IPS e.max Ceram; CAD-on-Zenostar Zr Translucent + Crystall./Connect + IPS e.max (R) CAD) were fabricated. Specimens (n=5) were cemented with a resin luting agent (Variolink (R) N; shade White) on three different shades (ND3, ND8 and ND9) of a tooth-colored resin substrate (IPS Natural Die Material). Spectral reflectance and color coordinates were measured using a spectroradiometer under standardized lighting conditions (CIE D65 illumination) and optical geometry 0/45 degrees. Color differences (Delta E-ab* and Delta E-00) from cemented specimens and CIELAB- and CIEDE2000-based translucency parameter (TP and TP00) from non-cemented specimens were calculated. Data was statistically analyzed using one-way ANOVA and Tukey's tests (alpha = 0.05). Delta E values were also analyzed using perceptibility (PT = 1.22 Delta E-ab* units; 0.81 Delta E-00 units) and acceptability (AT = 2.66 Delta E-ab* units; 1.77 Delta E-00 units) thresholds. Results. The cemented specimens of CAD-on, LDC, YZW and PICN on different substrates (ND3-ND8, ND3-ND9 and ND8-ND9) showed different Delta E-ab* and Delta E0(0) values (p <= 0.05), which were above AT. YLD-T showed Delta E-ab*and Delta E-00 values below AT for all comparisons. Lowest and highest TP and TP00 values were obtained for YLD-T and PICN, respectively (p <= 0.05). Significance. Resin-cemented YLD-T on different tooth-colored substrates showed less translucency as well as smaller color differences (below acceptability threshold), indicating the best masking ability among evaluated systems. (C) 2019 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.