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Transparency to UV-Vis light and radiopacity of dental resin composites containing zirconia (ZrO2) fillers were investigated. The transparency of the resin composite containing porous ZrO2 spheres was much higher than that containing irregularly shaped ZrO2 particles. Calcination of the porous ZrO2 spheres at high temperatures led to dramatically reduced specific surface areas and pore volumes. The transparency of the resin composite containing the calcined porous ZrO2 spheres drastically decreased as the calcination temperature increased. Then, the enhanced UV-Vis transmittance of the resin composite containing porous ZrO2 spheres is attributed to the concentration and physical characteristics of the pores. The radiopacity of the resin composites containing porous ZrO2 spheres increased slightly with increasing calcination temperature. This study revealed that the internal structure of the ZrO2 fillers mainly influenced in the UV-Vis light transmittance of the resin composites. [ABSTRACT FROM AUTHOR]

Light-curing resin cements, each comprising one of five different inorganic fillers (non-porous and porous spherical SiO2 particles, irregularly shaped glass and ZrO2 particles, and porous ZrO2 spheres), monomers, and polymerization initiators were prepared to determine the effect of filler morphology on the adhesive strength of the resin cement. The strength of adhesion to a computeraided design/computer-aided manufacturing (CAD/CAM) resin block was investigated mechanically by measuring the tensile bond strength, flexural strength, and elastic modulus. The resin cement containing sub-micron porous ZrO2 spheres had significantly higher tensile bond strength than the other resin cements. The resin cement containing the porous ZrO2 spheres had markedly lower flexural strength and elastic modulus values than the resin cements containing SiO2 and glass fillers. [ABSTRACT FROM AUTHOR]

Supramolecular donor–acceptor assemblies composed of carbon nanodiamond (ND) and porphyrin (Por) are constructed through interensemble hydrogen bonding and π–π interactions. Formation of the supramolecular clusters composed of ND and porphyrin has been confirmed by transmission electron microscopy (TEM), dynamic light scattering (DLS), and IR spectroscopy. The resulting supramolecular clusters have been assembled as three-dimensional arrays onto nanostructured SnO2films using an electrophoretic deposition method for the test of photoelectrochemical properties. Enhancement in the photoelectrochemical performance as well as the broader photoresponse in the visible region is seen with formation of the supramolecular clusters between ND and porphyrins as compared with the reference system without porphyrins. [ABSTRACT FROM AUTHOR]