background: esthetic demands among patients have led to the introduction of tooth-colored restorations. composite resins bond to enamel applying acid etch technique. total etch adhesion systems are still considered as golden standard among bonding systems. however, clinicians have tendency towards using adhesive systems with a simplified application procedure. the aim of the present study is to...

We describe the development of Lewis’s ideas concerning the chemical bond and in particular the concept of the electron pair bond and the octet rule. We show that the concept of the electron pair bond has endured to the present day and is now understood to be a consequence of the Pauli principle. In contrast the octet rule is now regarded as much less important than was originally generally bel...

this in-vitro study sought to assess the push-out bond strength of a total etch and 2 self-etch bonding systems to intracanal dentin of primary anterior teeth (pat).thirty-six primary anterior teeth were randomly divided into 3 groups of 5(th) generation (single bond 2), 6(th) generation (clearfil se) and 7(th) generation (single bond universal) bonding agents. the canal orifice was restored wi...

Short dangling bond wires (DB wires), fabricated on H-terminated Si(001) surfaces, show patterns of displacement that depend on their length. We have performed density function calculations, with and without spin-polarisation, designed to investigate the atomic and electronic structure of these wires. As expected, we find that even length wires are accurately modelled by non-spin polarised calc...

statement of the problem: monomer viscosity and solvent evaporation can be affected by the adhesive system temperature. higher temperature can elevate the vapor pressure in solution and penetration of adhesive in smear layer. bonding mechanism may be influenced by the adhesive temperature. purpose: this study aimed to evaluate the effect of pre-heating on shear bond strength of etch-and-rinse a...

objectives: this study aimed to compare the durability of four adhesive systems by assessing their microtensile bond strength (mtbs) and microleakage during six months of water storage. materials and methods: a total of 128 human third molars were used. the adhesives tested were scotch bond multipurpose (sbmp), single bond (sb), clearfil-se bond (cseb), and all-bond se (abse). after sample prep...