poor adhesion between two successive bituminous layers causes adverse effects on the structural strength of the pavement and develops a numbers of premature failure. to improve the adhesion, it is a general practice to apply a tack coat over an existing or newly constructed bituminous surface before laying another bituminous layer. the main objective of this study is to explore the influence of...

Introduction: In orthodontic treatment, it is essential to establish a satisfactory bond between enamel and bracket. After the self-etch primers (SEPs) were introduced for the facilitation of bracket bonding in comparison to the conventional etch-and-bond system, multiple studies have been carried out on their shear bond strengths which have yielded different results. This study was aimed at co...

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...