background and aims. the aim of the present study was to compare the effect of surface treatment with er; cr:yssg, nd:yag, and co2 lasers on repair shear bond strength of a silorane-based composite resin. materials and methods. sixty eight cylindrical samples of a silorane-based composite resin (filtek silorane) were prepared and randomly divided into 4 groups as follows: group 1: without surfa...

statement of problem: in some clinical situations, repair of composite restorations is treatment of choice. improving the bond strength between one new and old composite usually requires increased surface roughness to promote mechanical interlocking since chemical bonding might not be adequate. similarly, the treatment of a laboratory fabricated resin composite restoration involves the same pro...

In this Study, surface of medium carbon steel (AISI 1045) was modified by titanizing followed by plasma nitriding. Titanizing was performed using pack cementation method, in a pack mixture of ferrotitanium, ammonium chloride and alumina, at 1223 K for 45 and 180 min.  Plasma-nitriding was conducted at two temperatures of 803 and 823 K for 5 h, in a gas mixture of 75%N2+25%H2. The samples were c...

Nitriding is a surface treatment technique used to introduce nitrogen into metallic materials to improve their surface hardness, mechanical properties, wear resistance and corrosion resistance. In this research, the effects of plasma nitriding parameters including frequency and duty cycle were investigated on samples with different grooves dimensions. Steel blocks prepared from DIN1.2344 hot wo...

Surface properties play a critical role in influencing cell responses to a biomaterial. The objectives of this study were (1) to characterize changes in surface properties of zirconia (ZrO₂) ceramic after oxygen plasma treatment; and (2) to determine the effect of such changes on biological responses of human osteoblast-like cells (MG63). The results indicated that the surface morphology was no...

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