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...

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...

to evaluate the influence of core thickness and fabrication stages on the marginal accuracy of ips e.max press crowns.twenty ips e.max press crowns, 1.5mm thick, were fabricated on metal dies. the crowns had two different core thicknesses, 0.8mm for group a and 1mm for group b, ten for each group. marginal gap was measured after each stage of core fabrication, veneering and glaze firing. the sp...

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...

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...