background: dental surfaces prepared with different er:yag laser distance may have different characteristics compared with those prepared with conventional instruments. the aim of this study was to investigate the effect of er:yag laser irradiation distance from enamel and dentin surfaces on the shear bond strength of composite with self-etch and etch and rinse bonding systems compared with con...

objectives: repairing composite restorations is a challenging procedure especially when two different types of composites are used. this study aimed to compare the repair strength of silorane-based composite (sc) (filtek p90) with that of preheated sc, methacrylate composite (mc)(z250), flowable mc (filtek supreme plus) and different adhesive/composite combinations. materials and methods : eigh...

objectives: a reduction in bond strength of composite to bleached enamel has been reported immediately after bleaching treatment. application of some antioxidant agents may decrease the adverse effects of whitening agents on bond strength and enhance composite bond to enamel. this study aimed to assess the effect of green tea, sodium ascorbate, sage and grape seed extract on bond strength of co...

in this study, porcelain bond strength to three different alloys of gold-base, pd-ag and base-metal were compared and the effect of repeated porcelain sintering on bond strength was evaluated. the obtained results showed best bond strength of porcelain with gold-base alloy. pd-ag and base-metal alloys showed less strength respectively. during repeated sintering of porcelain, bond strength has n...

In this study, the concrete-steel bond strength of concrete filled cylindrical steel tubes has been experimentally investigated. 22 short, high strength and normal concrete filled circular steel tubes were tested. Push-out test was carried out as the common method to evaluate the bond carrying capacity. Four different concrete mixes were used in preparing the specimens. The steel tubes were w...

Background: Resin cements are widely used for cementation of FRC posts, but their bond strength can be influenced by cement type and cementation technique. The aim of this study was to determine the effect of type of resin cement and cementation technique on the bond strength of fiber posts. Methods: Forty five extracted mandibular premolars with a minimum roo...

The concept of Resonance Assisted Hydrogen Bond (RAHB), which usually occurs in b diketons, has a remarkable role in chemistry. These molecules, which contain heteroatom particularly O and N, are species with biological interest in protein folding and DNA pairing. Therefore, the amplification of hydrogen bonds strength by substituents may be important in life scie...