Optical and colorimetric evaluation of a multi-color polymer-infiltrated ceramic-network material.

Objective: To evaluate color, translucency parameter and optical properties (scattering (S), absorption (K) and transmittance (T)) of a multi-color polymer-infiltrated ceramic-network (PICN) material.

Methods: Samples of shades 1M1-HT, 1M2-HT, 2M2-HT, 3M2-HT, and 4M2-HT from VITA ENAMIC multiColor (E-MC) High Translucent were fabricated (n = 3). CAD-CAM blocks were cut and polished to 1.00 ± 0.01 mm of thickness. Diffuse reflectance and color coordinates were measured against white and black backgrounds, using a calibrated spectroradiometer, CIE D65 illuminant and the CIE 45°/0° geometry. Color and translucency differences were evaluated using 50:50% perceptibility (PT and TPT) and 50:50% acceptability (AT and TAT) thresholds. S and K coefficients and T were calculated using Kubelka-Munk's equations. Data was statistically analyzed using Kruskal-Wallis, Mann-Whitney tests, and VAF coefficient.

Result: Mean C* and b* values increased from incisal to cervical layers with statistically significant differences (p < 0.05). In general, ΔE between sequential layers were above PT for all shades. In addition, translucency parameter (TP) increased from cervical to incisal and ΔTP values were greater than TPT and lower than TAT between all sequential layers. Layers from all shades showed similar spectral behavior for S (97.4% ≤ VAF), K (85.0% ≤ VAF) coefficients and T (95.3% ≤ VAF). However, these values presented significant differences (p < 0.05) from cervical to incisal layers.

Significance: The gradient in color and translucency of this novel CAD-CAM multi-color PICN material can assist dental technicians and dentists to reach greater esthetics than the pre-existing CAD-CAM monolithicmaterials.