introduction: whitening toothpastes which have been accepted in populations may affect properties of enamel and restorative materials. the aim of this study was to compare the microhardness of human enamel and z250 microhybrid composite resin after brushing with two whitening toothpastes. materials and methods: in this experimental study of enamel specimens, forty five freshly extracted human i...

objectives: the aim of this study was to compare polymerization depth of two bulk-fill and one conventional composite cured for different times. methods: this in vitro experimental study was conducted on 54 composite samples (2×4×10mm) fabricated of tetric n-ceram bulk-fill, x-tra fil bulk-fill, and grandio conventional composite cured for 20, 30, and 40 seconds. the microhardness of samples wa...

tooth fracture is a common dental problem. by extension of cavity dimensions, the remaining tooth structure weakens and occlusal forces may cause tooth fracture. the aim of this study was to evaluate and compare the fracture resistance of teeth restored with direct and indirect composite restorations.sixty-five sound maxillary premolar teeth were chosen and randomly divided into five groups eac...

objectives: this study sought to compare the push-out bond strength of two bulk-fill and one conventional composite to intracanal dentin in primary anterior teeth. materials and methods: this in vitro, experimental study was conducted on 39 primary anterior teeth, which were randomly divided into three groups. after cleaning and shaping, the root canals were filled with metapex in such a way th...

We recently reported that the activation of NF-kappaB and AP-1 was suppressed in monocytes infected with measles virus, but not in infected epithelial cells. This cell-type-specific suppression of the inflammatory response represents a potential for measles virus to evade host immune system. In the current study, we examined the suppression mechanism of lipopolysaccharide (LPS)-induced, namely ...

A relatively unexplored nexus in Drosophila Immune deficiency (IMD) pathway is TGF-beta Activating Kinase 1 (TAK1), which triggers both immunity and apoptosis. In a cell culture screen, we identified that Lysine at position 142 was a K63-linked Ubiquitin acceptor site for TAK1, required for signalling. Moreover, Lysine at position 156 functioned as a K48-linked Ubiquitin acceptor site, also nec...

This review paper illustrates the main normal and superconducting state properties of magnesium diboride, a material known since early 1950's, but recently discovered to be superconductive at a remarkably high critical temperature Tc=40K for a binary compound. What makes MgB2 so special? Its high Tc, simple crystal structure, large coherence lengths, high critical current densities and fields, ...

statement of problem: in some clinical situations, repair of composite restorations is treatment of choice. improving the bond strength between one new and old composite usually requires increased surface roughness to promote mechanical interlocking since chemical bonding might not be adequate. similarly, the treatment of a laboratory fabricated resin composite restoration involves the same pro...

Nanosized metal oxides dispersed polymer composites constitute a fascinating class of polymer composite materials. Synthesis of such composite materials through solvent casting enhances the polymer synthetic technology. Solvent casting method was used to prepare Cobalt oxide (Co3O4) dispersed Poly (methyl methacrylate) (PMMA) nano composite<span style="text-decoration: und...