Effect of Adhesive Resin as a Modeling Liquid on Elution of Resin Composite Restorations

Background. Adhesive resin is increasingly used as a modeling liquid for composite. Based on previous studies, elution of some components from the composite mass negatively affects the oral tissues. Since few studies have focused on the effect of adhesive resin on composite mass, this study aimed to investigate the effect of dental adhesion factors as modeling liquid on the elution of substances from composite restorations. Materials and Methods. Sixty-four composite specimens (6 × 2 mm diameter × height) were prepared in four groups (n = 16) by using a Teflon ring. Composite mass was incrementally applied in four layers (0.5 mm). The control group contained no material between the layers, but other groups had one of the single bond, SE bond, and wetting resin adhesives between the layers. Specimens were immersed in distilled water and methanol. The amount of released triethylene glycol dimethacrylate (TEGDMA), urethane dimethacrylate (UDMA), and camphorquinone (CQ) was monitored by gas chromatography after 24 hours and 7 days. Data were analyzed with SPSS software through Kruskal–Wallis and Mann–Whitney U tests (α = 0.05). Results. The highest rate of released TEGDMA comonomer was seen in the wetting resin group in the water medium. The highest rate of released UDMA monomer was seen in SE bond and wetting resin groups in the methanol medium after 24 hours. The highest amount of released CQ in the methanol medium was observed in the SE bond group after 7 days. Conclusion. Single bond adhesive can be used as modeling liquid since it has no significant effect on the elution of components from composite mass. Whereas, wetting resin and SE bond adhesives are not suitable to be used as modeling liquid due to the high amounts of released TEGDMA and UDMA.

Catalytic Transfer Hydrogenation of Biomass Derived 5-Hydroxymethylfurfural into 2,5-Dimethylfuran in a Methanol Medium

The hydrogenation of HMF has been conducted in a methanol medium, which served as hydrogen donor and solvent. Without any additive, HMF was hydrogenated to 2,5-dimethylfuran (DMF) with complete conversion and selectivity (64%) using well-ordered mesoporous MCM-41 with high nickel content as catalyst at 190 °C in 5 h. Two kinds of mesoporous molecular sieve catalysts were prepared by impregnation and in-situ synthesis. Different reaction parameters such as the amount of Ni, reaction time and temperature were optimized to achieve the highest catalytic activity. Moreover, the plausible reasons for the difference in catalytic effects between the two types of catalysts were also discussed.

A macrocyclic tetranuclear ZnII complex as a receptor for selective dual fluorescence sensing of F− and AcO−: effect of a macrocyclic ligand

Fluorimetric detection of F−/AcO− with an additional ‘INHIBIT’ logic gate response for F−/H+ and AcO−/H+ in an aqueous-methanol medium by a 48-membered macrocyclic ZnII-complex DAS has been explored by combined experimental and theoretical study.

Role of a 2,3-bis(pyridyl)pyrazinyl chelate bridging ligand in the reactivity of Ru(ii)–Pt(ii) dinuclear complexes on the substitution of chlorides by thiourea nucleophiles – a kinetic study

Effect of a bridged ligand on the chloride substitution from hetero bimetallic Ru(ii)–Pt(ii)dichlo complexes by thiourea nucleolus was studied in a methanol medium (I = 0.10 M) under pseudo-first-order conditions.