This study investigated the effects of resin composites (RCs) containing surface pre-reacted glass ionomer (S-PRG) filler on the dentin microtensile bond strength (μTBS) of HEMA-free and HEMA-containing universal adhesives (UAs). Water sorption (WS) and solubility (SL), degree of conversion (DC), and ion release were measured. The UAs BeautiBond Xtreme (BBX; 0% HEMA), Modified Adhesive-1 (E-BBX1; 5% HEMA), Modified Adhesive-2 (E-BBX2; 10% HEMA), and two 2-step self-etch adhesives (2-SEAs): FL-BOND II (FBII; with S-PRG filler) and silica-containing adhesive (E-FBII) were used. Teeth were restored with Beautifil Flow Plus F00 with S-PRG filler (BFP) and flowable resin composite with silica filler (E-BFP). μTBS was evaluated after 24 h and 6 months of water storage. WS and SL measurement followed ISO 4049:2019; spectroscopy measured DC; ICP-MS evaluated ion release. BBX and FBII presented the highest DC. The adhesives did not comply with the WS ISO requirements, but the bonding resin of 2-SEAs complied with the SL threshold. BFP released more ions than E-BFP. BFP positively affected the μTBS of UAs, regardless of HEMA concentration after 24 h, comparable to the 2-SEAs. The 6 months μTBS decrease depended on the adhesive and RC combination. HEMA did not affect the μTBS of UAs, while bioactive resins had a positive impact.

Background: This study aimed to evaluate the color matching, light transmittance, and reflectance characteristics of the novel flowable resin composite OCF-001 (OCF). Methods: Fifty-four resin composite molds were made with simulated class I cavities of A2, A3, and A4 shades by filling the rubber mold interspace with Estelite Sigma Quick (ESQ), Gracefil Putty (GP) and Filtek Supremme Ultra (FSU). After applying the adhesive, three different flowable resin composites (n = 6), OCF, Gracefil LoFlo (GLF), and Supreme Ultra Flowable (SUF), were used to fill the cavities. A colorimeter was used to measure the color parameters (CIEDE2000). The color measurements were taken immediately and after 28 days. Data were analyzed using the nonparametric Kruskal–Wallis (α = 0.05) and Wilcoxon tests. The light transmittance and reflection characteristics were measured with a black background using a spectrophotometer under D65 illumination. Results: The ΔE₀₀, and ΔC of OCF was lower than other tested materials in A2 and A3 shades both immediately and after 28 days. OCF showed the highest transmittance characteristic, and a relatively stable reflectance curve in all the wavelengths. Conclusions: OCF showed better shade matching with the surrounding shades of A2 and A3, a relative uniform reflectance and higher light transmission properties.

Background: This study aimed to evaluate the color-matching and light transmission properties of a newly developed aesthetic flowable resin composite, OCFB-001. Methods: Rubber molds containing cylindrical cavities were filled with Estelite Sigma Quick, and 40 resin composite (CR) molds with simulated Class I cavities were prepared in shades A1, A2, A3, and A4, resulting in a total of 160 samples. Following bonding procedures, four different flowable resin composites (n = 10) were introduced into the cavities. The color difference (ΔE₀₀) was calculated using two methods. A two-way analysis of variance was performed, and the interaction was significant, so a post hoc analysis was performed for each shade using Bonferroni’s correction. The morphology of the filler in each material was observed via scanning electron microscopy (SEM). Results: In the A1 shade, OCFB-001 demonstrated color differences comparable to those of other materials. However, in the A2, A3, and A4 shades, OCFB-001 exhibited significantly lower color differences (ΔE₀₀) than the other materials, with a more consistent distribution. SEM analysis revealed that the OCFB-001 structure resembled that of Estelite Bulk Fill Flowable. Conclusions: OCFB-001 showed excellent shade matching in the A2, A3, and A4 ranges and good matching in the A1 shade, on par with existing universal-shade flowable bulk-fill resin composites.

This in vitro study aimed to investigate whether color differences in the stained cavity floor simulating recurrent caries can be detected using various restored resin composites. Artificial teeth were made with conventional resin composite (Estellite Sigma Quick A3; ET), and class V cavities were prepared. To simulate the color of caries, a dot was marked in the center of the cavity floor using four different magic pens. The cavities were filled with ET and two universal shade resin composites (UC, Omnichroma; OMI, Essentia Universal; ESS). For photographic analysis, a standard correction color chart was used. The color difference (ΔE₀₀) between (i) the lab value at the center of the cavity and (ii) the average lab value at 1 mm mesial and distal to the center of the cavity was calculated. The data were statistically analyzed using two-way ANOVA (p < 0.05). For visual analysis, 25 dentists were asked to complete a questionnaire to determine whether the color differences were noticeable. In the photographic analysis, UC showed larger ΔE₀₀ values than ET in all colors. Visual analysis revealed higher detection rates for UC than ET. Universal shade resin composite tends to reflect the color of the cavity more effectively than conventional resin composite.