polyacrylonitrile (pan) membranes with nano-porous surface and high hydrophilicity were fabricated by addition of polyoxyethylene (40) nonylphenyl ether (igepal) as an additive in the casting solution. the membranes were prepared from pan/igepal/1-methyl-2-pyrrolidone (nmp) via phase inversion induced by immersion precipitation technique. pure water was used as coagulation medium. the effects o...

objective: repair of an indirect restoration is usually preferred over its replacement. this study aimed to evaluate the effect of silane in different surface preparation techniques on the bond strength of direct to indirect composite resin.   methods: for this in vitro experimental study, 48 indirect composite cubes were fabricated, divided into 4 groups of 12 and subjected to the following pr...

in this investigation the thickness of enamel in the gingival, middle, and incisal thirds of the labial surface of the anterior teeth were measured regarding preparation of the teeth for porcelain laminate veneers.part one, 20 extracted intact human maxillary central and lateral incisors ten of each were selected. the teeth were imbedded in autopolimerize acrylic resin. cross section was prefor...

the purpose of this study was to compare shear bond strength (sbs) of orthodontic brackets bonded to enamel prepared by er:yag laser with two different powers and conventional acid-etching.forty-five human premolars extracted for orthodontic purposes were randomly assigned to three groups based on conditioning method: group 1- conventional etching with 37% phosphoric acid; group 2- irradiation ...

In comparison to the previous researches, ZrO2 nanoparticles with higher surface area (85 m2/g) have been synthesized in this research. The as-prepared ZrO2 nanoparticles by co-precipitation method were characterized with X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). The surface area of the s...

Surface microsurgery is the science of preparing surface layers, such as oxide scales and coatings, for characterisation of their microstructure and composition, by conventional surface analytical techniques, such as SEM, EPMA, SIMS etc. A surface microsurgery procedure often employed involves the preparation of a taper section. Using relatively simple equipment, significant improvements have b...

in comparison to the previous researches, zro2 nanoparticles with higher surface area (85 m2/g) have been synthesized in this research. the as-prepared zro2 nanoparticles by co-precipitation method were characterized with x-ray diffraction (xrd), scanning electron microscopy (sem) and transmission electron microscopy (tem). the surface area of the sample was characterized by bet method. the eff...