direct composite resin restorations are widely used and the impact of different storage temperatures on composites is not well understood. the purpose of this study was to evaluate the microtensile bond strength of composite to dentin after different pre-curing temperatures.occlusal surfaces of 44 human molars were ground with diamond burs under water coolant and polished with 600 grit silicon ...

The effect of impurities which induce local interlayer tunneling in bilayer exciton condensates is discussed. We show that a localized single-fermion bound state emerges inside the gap for any strength of impurity scattering and calculate the dependence of the impurity state energy and wave function on the potential strength. We show that such an impurity-induced single-fermion state enhances t...

We utilize classical molecular dynamics to study the effects of intrinsic, interlayer friction between graphene monolayers, as well as extrinsic attachment or clamping strength between graphene and a model silicon substrate on the energy dissipation Q-factors of oscillating graphene nanoresonators. Both interlayer friction and attachment effects are found to significantly degrade the graphene Q...

background: based on contradictory findings concerning the use of lasers for enamel etching, the purpose of this study was to investigate the shear bond strength of teeth prepared for bonding with er-yag laser etching and compare them with phosphoric acid etching. materials and methods: in this in vitro study forty – eight premolars, extracted for orthodontic purposes were randomly divided in t...

objective: this study evaluated the influence of storage time on micro-shear bond strength of two self-etching materials to enamel and dentin. materials and methods: human third molar teeth were sectioned to 1.5 mm thick beams and randomly divided into 2 groups. in group i, se bond and in group ii, tri-s bond was used to bond a composite rod (ap-x) to each treated surface. specimens were prepar...

introduction : this in vitro study was designed to evaluate the effect of smear layer removal on push-out bond strength of white mineral trioxide aggregate (wmta) and calcium-enriched mixture cement (cem). materials and methods: dentin discs with 3 mm thicknesses were divided into 4 groups ( n =15): group 1: irrigation of the canal with normal saline and filling with wmta; group 2: irrigation w...

objective: the objective of this study was to compare the tensile bond strength of metal brackets bonding to glazed ceramic surfaces using three various surface treatments. materials and methods: forty two glazed ceramic disks were assigned to three groups. in the first and second groups the specimens were etched with 9.5% hydrofluoric acid (hfa). subsequently in first group, ceramic primer and...

As a prospective candidate material for surface coating and repair applications, nickel-based superalloy Inconel 718 (IN718) was deposited on American Iron and Steel Institute (AISI) 4140 alloy steel substrate by laser engineered net shaping (LENS) to investigate the compatibility between two dissimilar materials with a focus on interface bonding and fracture behavior of the hybrid specimens. T...