The retention of zirconia-based ceramic posts (CosmoPost system) luted with glass ionomer and resin cements was evaluated. Thirty-two extracted, caries-free, unrestored teeth were selected and stored in chlorhexidine and water solution. The teeth were endodontically treated and randomly assigned to two groups (n=16). Each tooth was decoronated and prepared to a depth of 10.0 mm from root surfac...

BACKGROUND Newer dentin bonding agents were developed to improve the quality of composite restoration and to reduce time consumption in its application. The aim of the present study was to evaluate tensile bond strength of 6(th), 7(th) and 8(th) generation bonding agents by in vitro method. MATERIALS AND METHODS Selected 60 permanent teeth were assigned into 20 in each group (Group I: 6(th) g...

The effects of hydrostatic extrusion on particle cracking and on the subsequent tensile properties of some prototypical particlereinforced metal–matrix composites are investigated. In most cases, tensile failure occurs through a plastic instability in accordance with the Considere criterion for necking. The corresponding failure strain is therefore dictated by the global flow and hardening char...

objective: the objective of this study was to compare the tensile bond strength of metal brackets bonding to glazed ceramic surfaces using three various surface treatments. materials and methods: forty two glazed ceramic disks were assigned to three groups. in the first and second groups the specimens were etched with 9.5% hydrofluoric acid (hfa). subsequently in first group, ceramic primer and...

In this paper, a new method is proposed for the production of MWCNTs/PVC (multi-walled carbon nanotubes/ polyvinyl chloride) nanocomposites. In this method, a spray is used to produce layers of carbon nanotubes within a PVC matrix. Various parameters influence the production of the nanocomposite and its mechanical properties. These parameters are studied separately and the effect of each of par...

Indentation testing has frequently been used as a method to obtain the material properties of articular cartilage in compression [1]. To account for the wellestablished anisotropic nature of cartilage [2] previous studies have modeled the cartilage as a transversely isotropic biphasic material using optimized FEM curvefitting techniques to obtain the material properties of the tissue in compres...

BACKGROUND The luting cements must withstand masticatory and parafunctional stresses in the warm and wet oral environment. Mouth temperature and the temperature of the ingested foods may induce thermal variation and plastic deformation within the cements and might affect the strength properties. The objectives of this study were to evaluate the effect of temperature on the compressive and diame...