Objective To evaluate color, lightness, chroma, hue, and translucency adjustment potential of resin composites using CIEDE2000 color difference formula. Methods Three resin composites (Filtek Universal, Harmonize, and Omnichroma) were tested. Two types of specimens were prepared: an outer base shade with an inner hole filled with test shades and single‐composite specimens of all shades. Spectrorradiometric reflectances measurements and subsequent CIELAB color coordinates and translucency parameter (TP) were performed. Color (CAP00), lightness, chroma, hue, and translucency (TAP00) adjustment potential using CIEDE2000 color difference were computed. Color and transparency differences among composite materials and shades were statistically tested (P < 0.05). Results Positive CAP00 and TAP00 values were found for majority of tested materials. CAP00 values ranged from −0.14 to 0.89, with the highest values found for Omnichroma (>0.75 in all cases). TAP00 values ranged from −0.06 to 0.86 with significant translucency differences among dual and single specimens. Omnichroma exhibited the highest adjustment potential for all color dimensions studied. Conclusions Lightness, hue, chroma, and translucency adjustment potential have been introduced using CIEDE2000 color difference formula, and have shown their usefulness to evaluate blending effect in dentistry. Color coordinates and translucency adjustment potential were dependent on dental material. Omnichroma exhibited the most pronounced blending effect. Clinical significance Resin composites with increased color and translucency adjustment may simplify shade selection, making this process easier and less time consuming. Furthermore, these materials might facilitate challenging and complex color matching situations.

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Objective Evaluate the masking ability of bleach‐shade resin composites applied by multilayering techniques over colored substrates. Materials and methods Disc‐shaped specimens were fabricated from bleach‐shade resin composites using different multilayering techniques. Substrates were produced in opaque ceramic discs simulating colored substrates (A2, A3, A3.5, C2, C3, C4) and a bleached tooth (0M1). Color coordinates were obtained using a reflectance spectrophotometer. Color difference was calculated by CIEDE2000 using coordinates of 0 M1 ceramic as standard reference. Data were analyzed by one‐way ANOVA and Tukey's post‐hoc test (p ≤ 0.05). Masking ability interpretation was based on perceptibility and acceptability thresholds. Results All combinations presented ΔE00 above the acceptable threshold (ΔE00>1.8), ranging from 2.49 to 7.42, regardless of the restorative system, multilayering strategy or substrate color. Multilayering combinations placed over A2, A3 and A3.5 were moderately (1.8<ΔE00≤3.6) and clearly unacceptable (3.6<ΔE00≤5.4), combinations associated with C2, C3 and C4 were clearly unacceptable and, extremely unacceptable (ΔE00>5.4). Lower ΔE00 was observed for combinations with 0.5 mm extra white enamel layer (2.49), or 1.0 mm white dentin layer (2.69), over A2 and A3.5 substrates. Lightness difference showed the greatest contribution to ΔE00. Conclusions Bleach‐shade resin composite systems applied by the multilayering technique were not able to ensure effective masking ability. Clinical significance Bleach‐shade resin composites applied with different combinations of the multilayering technique were not effective in masking colored substrates. Alternative strategies, techniques and dental materials should be explored to obtain acceptable masking.

Objective To analyze translucency variations among four different contemporary esthetic ceramic systems having different shades and thicknesses. Material and Methods Ceramic specimens having different shades and translucencies were tested: leucite reinforced glass–ceramic (ECAD), conventional feldspathic ceramic (Noritake), zirconia reinforced lithium silicate glass–ceramic (Suprinity) and hybrid ceramic (Enamic). Specimens of 0.6, 0.9, 1.2, 1.5 and 2.0‐mm thickness (n = 3/group, 615 total) were prepared. Translucency (TP) and Relative Translucency (RTP) Parameters were calculated from spectroradiometric color readings. Effects of shade and thickness for a given system were statistically analyzed using MANOVA and Tukey post‐hoc multiple comparisons tests. Translucency variations were assessed comparatively with literature‐based perceptibility and acceptability thresholds. Results TP/RTP values of all ceramic materials decreased with increasing thickness. The most translucent specimens were 0.6‐mm thick ECAD HT‐A3.5 (TP = 31.99) and ECAD HT‐C2 (RTP = 23.75), while the least translucent was 2‐mm thick Enamic T‐3 M2 (TP = 7.27; RTP = 4.79). Thickness and material type significantly influenced translucency (p < 0.001). Noritake and ECAD LT showed similar translucency values, as well as Suprinity HT and ECAD LT. Conclusions For ceramic restorations thicker than 0.9‐mm, any thickness increase of 0.3–0.5 mm produces a perceptible but clinically acceptable translucency variation. Increases in thickness larger than 0.6‐mm will result in an unacceptable translucency shift. Dental practitioners need to recognize key factors that influence translucency of ceramic restorations in order to choose the optimal material, shade, translucency, and thickness suitable for different clinical scenarios. While shade plays a minor role in translucency variation, ceramic type and restoration thickness significantly affect overall translucency.

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