background and aims. polymerization efficacy affects the properties and performance of composite resin restorations. the purpose of this study was to evaluate the effectiveness of polymerization of two micro-hybrid, two nano-hybrid and one nano-filled ormocer-based composite resins, cured by two different light-curing systems, using fourier transformation infrared (ft-ir) spectroscopy and vicke...

A composite material is a combination of two or more materials arranged in the form of layer one on the other layer using binding material through some prescribed methods. In the Glass fibre coconut fibre human hair hybrid composite method, the epoxy resin is used as binding material, in which one layer is formed of glass fibre, followed by coconut fibre and then by human hair. By using hand la...

Aims: The aim of this study was to investigate the effect of flowable composite, as an intermediate layer between feldspathic porcelain and composite, on bond strength during intra-oral porcelain repair and its potential role in providing a long-lasting repair. Methods: Forty feldspathic porcelain (VMK 95) specimens were fired in metal ingots. They were airborne-particle abraded, etched with 4%...

OBJECTIVES The aim of this finite elemental stress analysis study was to evaluate the effect of cavity shape and hybrid layer on the stress distribution of the mandibular premolar tooth under occlusal loading. METHODS The mandibular premolar tooth was selected as the model based on the anatomical measurements suggested by Wheeler. Four different mathematical models were evaluated: 1) a saucer...

Polymer matrix composites used in different industrial applications due to their enhanced mechanical properties and lightweight. However, these materials are subjected to friction and wear situations in some industrial and automobile applications. Therefore, there is a need to investigate the wear properties of polymer matrix composite materials. This article emphasizes the dry abrasive wear be...

Composite materials can be defined as a combination of two or more materials that results in better properties than those of the individual components used alone. These materials have high strength and stiffness combined with low density compared to the conventional metals. Polymers are structurally more complex than metals. Polymer – matrix composites are viscoelastic materials and their mecha...

This in vivo study evaluated the clinical performance and appearance of a flowable resin composite and a hybrid resin composite over two years. Twenty-eight (28) pairs of restorations of a flowable resin composite and a conventional hybrid resin composite were placed in non-carious, asymptomatic facial Class V lesions. The restorations were evaluated at baseline, six, twelve, eighteen and twent...

in the present research, in contrast to the available papers, not only the superelasticity but also the shape memory effects are taken into account in determination of the impact responses. at the same time, in addition to modifying brinson’s model for the shape memory alloys (smas), to include new parameters and loading events, and hertz contact law, distributions of the sma phases are conside...

OBJECTIVES The aim was to evaluate the color stability and water uptake of two hybrid composite resins polymerized in two different conditions after exposure to commonly consumed beverages. In addition, the effect of repolishing and bleaching on the stained composite was evaluated. METHODS Eighty specimens (12 mm × 12 mm × 3 mm) were made from two hybrid composite resins of shade A2. Forty sp...

OBJECTIVES The aims of this study were to test whether the bond strength of a hybrid composite and a PMMA-based veneer to CAD/CAM polymers would improve after pre-treatment and to evaluate the failure types after debonding. MATERIALS AND METHODS Three types of PMMA-based (CAD-Temp, artBloc Temp and TelioCAD) CAD/CAM blocks were obtained (N = 360, n = 15 per test group). They were divided into...