The marginal fracture toughness of several types of composite resins was determined by means of the rattler test. Microparticle-filled resins showed significantly higher marginal fracture toughness than conventional composites. Posterior restorative composites were intermediate between MFRs and conventional composites. Amalgams were inferior to restorative resins. These data correspond with the...

BACKGROUND Chemicals that have estrogenic activity (EA) can potentially cause adverse health effects in mammals including humans, sometimes at low doses in fetal through juvenile stages with effects detected in adults. Polycarbonate (PC) thermoplastic resins made from bisphenol A (BPA), a chemical that has EA, are now often avoided in products used by babies. Other BPA-free thermoplastic resins...

A new, easy and cost-effective synthetic procedure for the preparation of thermosetting melamine-based epoxy resins is reported. By this innovative synthetic method, different kinds of resins can be obtained just by mixing the reagents in the presence of a catalyst without solvent and with mild curing conditions. Two types of resins were synthesized using melamine and a glycidyl derivative (res...

Ustiloxins are cyclopeptide mycotoxins produced by Villosiclava virens, the pathogenic fungus of rice false smut disease. Both resins SP207 and SP700 were screened to show the best adsorption and desorption properties for ustiloxins A and B among 20 commercial macroporous resins. Dynamic adsorption and desorption tests were carried out to optimize the process parameters. The optimal conditions ...

Thin-layer chromatography/flame ionization detection (TLC/FID) allows for the fractionation of bitumen into four fractions, namely, the saturates, the aromatics, the resins A and the resins B (SARAB). The technique is rapid and economical, but it lack reproducibility. The effect of chromarod aging on reproducibility was investigated along with that of the time between bitumen dissolution and it...

The color of 24 commercially available denture resins was determined visually with Munsell color tabs and by reflection spectrophotometry. Correlation between Munsell and spectrophotometric data was found. The resins characterized for Black patients had a higher degree of specular reflectance and were more opaque than resins for Caucasians.

Poly(4-vinylpyridine), 4VP, resins cross-linked with oligo(ethylene glycol dimethacrylates) were used for chelating resins. Sorption for some metal ions by complexation in acetate buffer (pH 3-6) was investigated mainly by using the 4VP resins cross-linked with hydrophilic tetraethylene glycol dimethacrylate (4VP-4EG) and that cross-linked with hydrophobic divinylbenzene (4VP-DVB). The differen...

The use of epoxy resins in metal structures for adhesive reasons is getting wider. Epoxy resins possess enhanced mechanical, chemical and physical properties, i.e. increased shear and compression strength, resistance in solvents, as well as at high temperatures. Tensile tests were carried out with standard aluminium tension specimens glued with epoxy resins. The thickness of the glue and the ac...

Composites resins are the most popular restorative materials providing very good esthetics and long period of good clinical performance. Depth of cure of composite resins is crucial in determining the maximal increment thickness when restoring tooth cavities. In restorations with conventional composite resins the thickness of each increment has been defined as up to 2 mm. Bulk fill composite re...