Objective: The main aim of this study was to compare fracture load and fracture mode of yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) and metal-ceramic (MC) molar crowns using a modified test set-up to produce fractures similar to those seen in vivo, i.e. fractures of the veneering material rather than complete fractures. Materials and methods: 13 high-noble-alloy MC and 13 Y-TZP mo...

This article describes a simple procedure of recording contours of an existing cast post and core that needs to be reconstructed, using a polyvinyl siloxane material as a matrix for fabrication of a new cast post and core in a relatively short time with reduced cost. The procedure involves the use of an acrylic resin material under pressure, which minimizes void formation in the post-and-core p...

background: decrease of economically accessible uranium resources motivates consideration of breeding of fertile elements such as thorium. material and method: thorium oxide fuel burn up calculation of a simulated research reactor cooled heavy water has been proposed in the present work using mcnpx 2.6 code. two 233u and 235u isotopes have been used as fissile element of thorium oxide fuel. 135...

background : in anterior endodontically treated teeth a better esthetic can be achieved by using all-ceramic post -core restorations instead of metal post systems. maximum retention and fracture resistance of the post are the criteria upon which selection of a post system is based. the aim of this study was to evaluate the fracture resistance and retention of two all-ceramic post and core syste...

in this paper, a nonlinear free vibration analysis of thin annular functionally graded (fg) plate integrated with two uniformly distributed actuator layers made of piezoelectric (pzt4) material on the top and bottom surfaces of the annular fg plate is presented based on kirchhoff plate theory. the material properties of the fgm core plate are assumed to be graded in the thickness direction acco...