objective: comparing the effect of repeated opening of the container lid of two dentin adhesive systems, prime&bond; nt (p&b; nt) and ibond (ib), on shear bond strength. materials and methods: intact bovine lower incisors (n=60), fixed in acrylic were ran-domly divided into six groups (n=10). groups i and ii were set as control groups. p&b; nt and ib were applied on the samples after five days ...

Microtextural and experimental studies have yielded conflicting data on the relative mechanical strengths of muscovite and biotite [Wilson and Bell, 1979; Kronenberg et al., 1990; Mares and Kronenberg, 1993]. We propose a crystal-chemical resolution to this conflict, namely, that (001) dislocation glide in biotite is rate-limited by its fluorine content. Significant F(OH)_• substitution, and co...

We examine non-destructive testing (NDT) techniques that characterize the interlayer bond quality of idealized 3-D printed concrete, simulating a layup bond, in-situ. An experimental study evaluates four NDT methods (x-ray radiography, ultrasonic pulse velocity (UPV), vibration resonance, and multi-element array ultrasonics) to idealized, layered concrete specimens simulate layers structure. Th...

OBJECTIVES To investigate the effect of dentin moisture degree and air-drying time on dentin-bond strength of two different one-step self-etching adhesive systems. MATERIALS AND METHODS Twenty-four human third molars were used for microtensile bond strength testing of G-Bond and Clearfil S(3) Bond. The dentin surface was either blot-dried or air-dried before applying these adhesive agents. Af...

Objective: The purpose of the present study was to compare bond strength of different universal adhesives under three different testing conditions: when no pretreatment was applied, after 37% phosphoric acid etching and after glycine application. Materials and methods: One hundred and fifty bovine permanent mandibular incisors were used as a substitute for human teeth. Five different universal ...

The zero-temperature random-field Ising model is solved analytically for magnetization versus external field for a bilayered Bethe lattice. The mechanisms of infinite avalanches which are observed for small values of disorder are established. The effects of variable interlayer interaction strengths on infinite avalanches are investigated. The spin-field correlation length is calculated and its ...

Introduction: Various surface treatments have been used to improve the adhesion of resin cement to zirconia restorations. The present study aimed to investigate the effects of different surface treatments on the bond strength of resin cement to zirconia (Y-TZP) in clinical practice. Methods: thirty square Y-TZP samples were classified into three groups of 10, including group SB (50 µm sandblast...

The aim of the study was to evaluate the core veneer bond strength of graded zirconia combinations and compared those to conventional zirconia combinations after thermal and mechanical tests. Conventional zirconia-veneer combinations and graded zirconia-veneer combinations were made into cylinders. Prior to shear bond testing, half of each group was subjected to thermal and mechanical cycling t...