background: microleakage is still one of the defects of resin composites that can lead to treatment failure; and re-bonding technique is one of the effective ways to reduce it. this study evaluated the effect of re-bonding with a surface sealant or a dentin adhesive on microleakage in class v microhybrid, nanohybrid, and packable composite restorations. materials and methods: in this in vitro s...

structural properties and chemical composition change the photocatalytic activity in tio2-sio2 nanopowder composite. the sio2-tio2 nanostructure is synthesized based on sol–gel method. the nanoparticles are characterized by x-ray fluorescents (xrf), x- ray diffraction (xrd), tunneling electron microscopy (tem), field emission scanning electron microscopy (fe-sem), uv-vis. spectrophotometer and ...

objectives: composite repair is a minimally invasive and conservative approach. this study aimed to evaluate the effect of an additional hydrophobic resin layer on the repair shear bond strength of a silorane-based composite repaired with silorane or methacrylate-based composite. materials and methods: sixty bar-shaped composite blocks were fabricated and stored in saline for 72 hours. the surf...

OBJECTIVE The purpose of this study was to analyze the shear bond strength of a new composite resin to polymer-based composite substrates using various surface roughnesses and two kinds of polymer matrices. MATERIALS AND METHODS Particulate filler composite resin with cross-linked polymer matrix and fiber-reinforced composite with semi-interpenetrating polymer matrix were used as bonding subs...

BACKGROUND Enhancement of bond strength between new and old composite usually requires increased surface roughness of old composite to promote mechanical interlocking and subsequent coating with bonding agents to improve surface wetting and chemical bonding. So this study was carried out to evaluate and compare the effects of different surface treatments and repair materials on the shear bond s...

abstract statement of the problem: surface roughness is a key factor in the aesthetics of restorative dentistry as it can determine the clinical quality and success of restorative materials. the chemical process of dissolution in the presence of mechanical forces can accelerate the surface roughness of tooth-coloured restorative materials. objectives: to determine the degree of surface roughnes...

In cases where there are no suitable natural undercuts on the teeth which can be used to provide clasp retention for a partial denture artificial undercuts can be created by the application of a composite filling material. An in-vitro investigation was undertaken to assess the surface integrity of three different composite restorative materials following repeated cycles of movement of cobalt-ch...

background and aims. today light cured composites are widely used. physical and mechanical properties of composites are related to the degree of conversion. light curing unit (lcu) is an important factor for composite polymerization. aim of this study is evaluation of composite resins hardness using halogen and led light curing units. materials and methods. in this study, 30 samples of filtek z...

A modified hydrothermal method was developed to synthesize ZnO-CuO composite nanostructures. A free-standing film made of ZnO-CuO nanostructures was assembled on the surface of the hydrothermal solution with a smooth surface on one side and a spherical surface on the other side. The structure, growth mechanism and the optical properties of the composite nanostructures were studied. Structural c...