objectives: to assess the effect of lactic acid (la) on microleakage of silorane-based composite restorations and methacrylate-based composites with self-etch and etch-and-rinse bonding systems. materials and methods: class v cavities were prepared in 120 extracted human teeth, divided into four groups and restored as follows: 1. silorane-based composite+p90 adhesive system (p90); 2. filtek z25...

PURPOSE This in vitro study investigated the fracture resistance of endodontically treated premolars restored using silorane- or methacrylate-based composite along with or without fiber or nano-ionomer base. MATERIALS AND METHODS Ninety-six intact maxillary premolars were randomly divided into eight groups (n = 12). G1 (negative control) was the intact teeth. In Groups 2-8, root canal treatme...

Introduction: Bleaching treatments may negatively affect the surface quality of composite restorations existing in the mouth. This study sought to assess the effect of 16% and 35% carbamide peroxide on microhardness of silorane-based versus two methacrylate-based composite resins. Methods: A total of 54 discs were fabricated from FiltekP90 (P90), FiltekZ350XT(Z350) Enamel and Filtek Z250(Z25...

In this study, two-dimensional electro-mechanical analysis of a composite rotating shaft subjected to non-axisymmetric internal pressure and applied voltage is investigated where hollow piezoelectric shaft reinforced by boron nitride nanotubes (BNNTs). Composite structure is modeled based on piezoelectric fiber reinforced composite (PFRC) theory and a representative volume element has been cons...

This paper investigates axial compression process of multi-layered tubes with circular cross-section under the axial loading in the quasi-static condition using experimental method. Some specimens are prepared in seven different groups, namely; empty carbon/epoxy composite tubes, solid carbon/epoxy composite rods, empty copper tubes, composite tubes with silicon sealant filler, concentrically s...

In this paper, an optimization framework is developed for performance-based seismic design of composite moment frames consisting of concrete filled steel box columns and I-shaped steel beams. Material cost of the structure and seismic damage under severe earthquake ground motions are minimized as objective functions. Two design examples are presented to demonstrate the applicability and efficie...

the aim of this study was to assess the effect of 30% hydrogen peroxide on the microleakage of class v cavities restored with either a silorane-based composite or two methacrylate-based composites.a total of 96 standard class v cavities (1.5 × 2 × 3 mm) were prepared on the buccal surface of sound extracted human premolars with both enamel and dentin margins and randomly assigned into three gro...