Background: Effective polymerization of the composite resin is essential to obtain long term clinical success and has a great importance obtaining improved mechanical properties. The purpose of this study was to measure the effect of the light intensity of LED and QTH curing devices in relation to the light distances, on the hardness (KHN) of two light cure nano-resin composite. Material and Me...

In this work the variation of the surface mechanical properties of starch-based biomaterials with immersion time was followed using microhardness measurements. Two blends with very distinct water uptake capabilities, starch/cellulose acetate (SCA) and starch/poly(epsilon-caprolactone) (SPCL), were immersed in a phosphate buffer solution (PBS) at 37.5 degrees C for various times. The microhardne...

objectives: this study aimed to assess the effect of applying casein phosphopeptide–amorphous calcium phosphate (cpp-acp) paste, casein phosphopeptide–amorphous calcium phosphate fluoride (cpp-acpf) paste and sodium fluoride gel on surface microhardness of enamel after microabrasion. materials and methods: thirty freshly extracted human premolars were selected. all samples were subjected to har...

AIM To investigate the influence of different staining beverages on color stability, surface roughness and microhardness of silorane and methacrylate-based composite resins. MATERIALS AND METHODS Three different composite resins (Filtek Silorane, Filtek P60, Filtek Supreme XT) were tested. Thirty cylindrical specimens (10 × 2 mm) per material were prepared and polished with a series of alumin...

GH4169, a nickel-base heat-resistant alloy, usually has outstanding high-temperature strength, excellent thermal stability and good wear resistance. However, it is hard to cut and its machined surface quality and integrity are particularly sensitive to a manufacturing process employed. The study reported in this paper was conducted to initially, review existing research on machining-induced sur...

STATEMENT OF THE PROBLEM Acidic foods and drinks can erode composite resins. Silorane-based composite is a new low shrinkage composite with higher hydrophobicity which might resist the erosive effect of beverages. PURPOSE The aim of this study was to determine the effects of 100% orange juice and non-alcoholic carbonated beer on microhardness of a silorane-based composite in comparison with t...

OBJECTIVE The purpose of this study was to assess the effect of home-use bleaching agents containing 10% carbamide peroxide and 7.5% hydrogen peroxide on enamel microhardness and surface micromorphology. MATERIAL AND METHODS Enamel slabs (n=10) received the bleaching agents for 1 h/day and remained in artificial saliva solution for 23 h/day, during a total period of 21 days. Control group was...

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 Vicker...

The main purpose of this paper was to investigate the effect of a surface plastic deformation layer introduced by multi-pass ultrasonic surface rolling (MUSR) on the mechanical and fatigue properties of HIP Ti-6Al-4V alloys. Some microscopic analysis methods (SEM, TEM and XRD) were used to characterize the modified microstructure in the material surface layer. The results indicated that the mat...

Semi-IPNs with varying contents of poly(vinyl alcohol) (PVA), poly acrylamide (PAM) and crosslinker N,N’methylene bis acrylamide (MBA) were prepared by redox polymerization method. The structural and morphological properties were studied by Fourier transform infrared (FTIR) spectroscopy, environmental scanning electron microscopy (ESEM) and X-ray diffraction (XRD) methods, respectively. It was ...