abstract   statement of problem: fracture of veneering porcelain has been described as the most frequent reason for the failure of zirconia-based fixed restorations. objectives: the purpose of this study was to evaluate and compare the shear bond strength of a zirconium oxide core material to three commercial veneering ceramics. materials and methods: three types of veneering ceramics were sele...

Background: Our research aimed to compare the biaxial flexural strength of glass ceramic and two different monolithic zirconias after aging, examine fracture surfaces with scanning electron microscopy (SEM) perform elemental analysis energy dispersive spectroscopy (EDS). Methods: Two types CAD/CAM materials (Katana UTML Prettau Anterior) a lithium disilicate material (IPS emax Press) were selec...

Background and Aim: One of the problems of all ceramic restorations is their risk of fracture due to occlusal loads. The aim of the present study was to compare the effect of two marginal designs (shoulder and chamfer) on the fracture resistance of IPS-emax all ceramic restorations. Materials and Methods: One extracted maxillary first premolar received chamfer 50' marginal preparation (0.8 m...

Purpose: The purpose of this in vitro study was to evaluate the effect simulated gastric acidity on surface roughness different types dental ceramics. Methods: Fifty specimens were divided according type material into five groups (n=10), as follows: Partially stabilized zirconia (PSZ) (Prettaue),Fully (FSZ) (Prettaue Anterior), lithium disilicate ceramics (IPS. Emax), Zirconia-containing silica...

Background: To identify and compare the shade variations of various commonly used esthetic dental ceramics by calculating their total-color-difference (ΔE) translucency parameter (TP) using a spectrophotometer. Methods: In total, 165 disc specimens from three shades (A1, B1, C1) five ceramic materials (N = 55/shade; n 11/ceramic material group) were prepared (Metal-ceramic (MC), IPS e.max press...

Background: Marginal adaptation is critical for long – term success of crown and bridge restoration. Computer aided design / computer manufacture (CAD/ CAM) system gaining more importance in the fabrication dental Objective: The aim this study to evaluate effect crystallization firing on vertical marginal gap IPS. emax CAD crowns which fabricated with two different CAD/CAM systems .Materials Me...

BACKGROUND The field of dental ceramics for CAD-CAM is enriched with a new innovative material composition having a porous three-dimensional structure of feldspathic ceramic infiltrated with acrylic resins.The aim of this study is to determine the mechanical properties of Polymer-Infiltrated-Ceramic-Network (PICN) and compare its performance with other ceramics and a nano-ceramic resin availabl...