A 2mm thick layer of composite covering dentin restoratives with unfavorable esthetics is recommended for a final 'sandwich' restoration that is esthetically comparable to a conventional, mono-composite control restoration.

Objective To determine color changes in bulk‐fill composite and universal composite restorations with dissimilar dentin replacement materials in extracted teeth after staining in red wine. Materials and Methods Cylindrical, 4 mm deep, class I cavities were prepared in 140 human molars. Bottom 2 mm was restored with Biodentine (Septodont), everX posterior (GC) or experimental HAP inserts. Each dentin replacement material was covered with a 2‐mm layer of a universal composite Filtek Z250 or Z550 (3M ESPE) or Gradia Posterior (GC). Groups combining top composite layer and the underlying dentin replacement were designated as “composite_dentin replacement.” Filtek Bulk Fill (3M ESPE) and Tetric EvoCeram Bulk Fill (Ivoclar Vivadent) were placed as a single 4‐mm layer. Color measurements were performed using Vita Easyshade 4.0 (Vita Zahnfabrik) initially and after 48‐hours storage in red wine at 37°C. Results Color differences (ΔEoo) ranged between 2.1 ± 0.7 (Z250_HAP) and 7.8 ± 1.1 (Z550_everX). EverX resulted in higher ΔEoo of the overlying composite than HAP (P < .001) and Biodentine (P = .006). Generally, ΔEoo was affected more by decreasing lightness (ΔL′) than changes in chroma (ΔC′). Conclusions EverX resulted in higher ΔEoo of the restoration than Biodentine and experimental HAP after staining in red wine. No significant differences in ΔEoo may be expected in different composites with the same underlying dentin replacement material. The same was generally true for bulk‐fill and universal composites. Clinical Significance Similar extent of color changes may be expected in bulk‐fill and universal composites. Highly translucent everX might exhibit greater color differences irrespective of the capping composite than non‐translucent materials. Clinicians have a wider choice of composite materials to cover a particular dentin replacement material, for example, everX or Biodentine, as similar color differences may be expected in various overlying composite brands.

NTAP treatment of dentin prior to adhesive application increases dentin wetting and surface free energy facilitating better adhesive distribution on dentin surface compared to phosphoric acid etching and similar to the "self-etch" application protocol.

Objective: To determine if there are any differences in surface characteristics (surface roughness and contact angle) among different CAD/CAM materials indicated for fabricating implant-supported restorations, following all the material preparation protocols provided by the manufacturer.Materials and Methods: One-hundred forty-four specimens were divided into six groups: RBC (resin-based composite), PMMA (polymethyl methacrylate), PEEK (polyether ether ketone), ZP (zirconia polished), ZG (zirconia glazed) and CoCr 4 (CoCr 4 alloy). The experimental part included surface roughness (SR) and contact angle of water (WCA) analyses, fulfilled with Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM) view of surface topography. The data were analyzed using Kruskal-Wallis test with a Dunn's post hoc analysis, the correlation between measurements was tested using Spearman's rank correlation coefficient and all data were presented as mean ± SD.Results: ZG specimens were significantly rougher compared to other groups (p ≤ 0.05). The WCA measurements revealed significantly lower mean values in ZG group (p ≤ 0.05), contrary to PEEK and CoCr 4 , where significantly higher mean values were observed, compared to other groups (p ≤ 0.05). There exist a moderate negative correlation between the SR and WCA (ρ = À0.41). AFM 3D and SEM 2D images presented more or less heterogeneous surface of all materials.Conclusions: There were statistically significant differences in surface roughness and contact angle among tested material groups. Moderate negative correlation was found between surface roughness and contact angle of tested material groups.

Objective To analyze the effects of factors 'composite,' 'medium,' and 'time' on color, translucency, and sorption/solubility of sculptable universal composites for enamel layering upon immersion in colored beverages. Materials and methods Disk‐shaped specimens, 10 mm in diameter and 2 mm thick (n = 5/group), of ultrafine, hybrid composite Essentia (GC), microhybrid Gaenial Anterior (GC), nanofilled Filtek Ultimate Enamel and Body ( 3M ESPE) were immersed in red wine, coffee, or distilled water for 15 days. CIELab color coordinates were measured and CIEDE2000 (∆E00) and Translucency Parameter differences (∆TP00) were calculated. Sorption and solubility were determined according to ISO 4049:2009. Data were analyzed using the analyses of variance and Tukey's post‐hoc test (α = 0.05). Results Essentia and Gaenial exhibited the lowest and the highest staining‐dependent color differences, with mean ∆E00 range of 1.7–6.1 and 5.1–11.3, respectively (p < 0.05). ∆TP00 was more pronounced in wine than in coffee (p < 0.05). Sorption and solubility varied between 9.8 and 15.3 μg/mm3 and −1.6 and −5.4 μg/mm3, respectively, with positive correlation between ∆TP00 and sorption (p = 0.005). Conclusions Total color and translucency differences of sculptable composites for enamel layering were material‐, time‐ and medium‐dependent. Translucency differences positively correlated with sorption. Overall, the ultrafine, hybrid composite exhibited the best results in terms of color stability, sorption and solubility. Clinical significance Clinicians should be aware of differences in color stability of sculptable composites for enamel layering as these are directly exposed to discoloration in the oral environment and are directly related to patients' long‐term satisfaction and restoration longevity. Ultrafine, hybrid composite may be preferred due to better color stability, lower sorption and solubility compared to nanofilled and microhybrid composites evaluated in this study.