Search results for "Weibull modulus"
showing 8 items of 8 documents
The Effect of Taper and Apical Diameter on the Cyclic Fatigue Resistance of Rotary Endodontic Files Using an Experimental Electronic Device
2021
The aim of this study was to analyze the effect of the taper and apical diameter of nickel&ndash
Comparative characterization of a novel cad-cam polymer-infiltrated-ceramic-network.
2015
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 available for CAD-CAM systems. Material and Methods In this study a total of five different materials for CAD-CAM were investigated. A polymer-infiltrated ceramic (Vita Enamic), a nano-ceramic resin (Lava Ultimate), a feldspathic ceramic (Mark II), a lithium disilicate ceramic (IPS-e max CAD) and finally a Le…
Strength distribution in paper
1998
Abstract Tensile strength distributions are studied in four paper samples that exhibit a variety of brittle-to-ductile properties. 1005 tensile specimens were measured in each case. The standard Gumbel and Weibull distributions, and a recently proposed double exponential modification of the former are compared with the observations visually and using chi-squared and Kolmogorov–Smirnov tests. The Gumbel distribution fails to fit the data while the Weibull distribution gives satisfactory agreement. However, the double exponential distribution fits the data best, regardless of the ductility of the material.
Fracture Resistance of New Metal-Free Materials Used for CAD-CAM Fabrication of Partial Posterior Restorations
2020
Background and Objectives: To evaluate in vitro the fracture resistance and fracture type of computer-aided design and computer-aided manufacturing (CAD-CAM) materials. Materials and Methods: Discs were fabricated (10 ×
Fracture toughness of different monolithic zirconia upon post-sintering processes
2021
Background Surface treatments are expected to be a reason for alteration in fracture resistance of zirconia. This study evaluated the effect of post-sintering processes on the fracture toughness of different types of monolithic zirconia. Material and Methods Classical- (Cz) and high-translucent (Hz) monolithic zirconia discs (1.2 mm thickness, 14 mm in Ø) were prepared, and randomly divided for surface treatments with 1) as-glazed (AG); 2) finished and polished (FP); 3) finished, polished, and overglazed (FPOG); and 4) finished, polished, and heat-treated (FPHT) technique (n=15/group). Fracture toughness (KIC) was determined with indentation fracture toughness method at load 1 kg for AG, FP…
Influence of different veneering techniques and thermal tempering on flexural strength of ceramic veneered yttria partially stabilized tetragonal zir…
2019
Background Different technique for ceramic veneering and thermal tempering process are expected to be a reason for alteration in strength of ceramic veneered zirconia. This study evaluates the effect of different veneering technique and varied thermal tempering process on flexural strength of ceramic veneered zirconia. Material and Methods Ceramic veneered zirconia bars (25 mm length, 4 mm width, 0.7&1.0mm of zirconia & ceramic thickness) were prepared from zirconia block (e.max® ZirCAD), sintered at 1500°C for 4 hours, and veneered with ceramics with different techniques including CAD-fused using e.max CAD® (C), Pressed-on using e.max® Zirpress (P), and layering using e.max® ceram (L), wit…
Role of coefficient of thermal expansion on bond strength of ceramic veneered yttrium-stabilized zirconia
2017
Background Incompatible coefficient of thermal expansion (CTE) is supposed to be a reason for chipping of ceramic veneered zirconia. This study evaluates the effect of veneering ceramic at varied CTE on bond strength to zirconia. Material and Methods Zirconia disks (Z, O 10 mm, 1.0 mm thickness) were prepared from Y-TZP (Cercon®) and sintered at 1350°C for 6 hours. All zirconia disks were veneered with ceramics ((O 7.0 mm, 1.5 mm thickness) with varied CTE including VITADur® alpha (VDα), VITAVM®7 (VM7), VITAVM®9 (VM9), Cercon® ceramkiss (CCK), IPSe.max® ceram (IeC), and IPS dSIGN® (IdS) (n=15). The specimens were thermo-cycled (5-55 °C, 500 cycles) prior to determine the shear bond strength…
Effect of different sintering process on flexural strength of translucency monolithic zirconia
2018
Background Sintering process is responsible for the strength of zirconia restoration. This study evaluated the effect of different sintering temperatures and sintered-holding times on flexural strength of translucency monolithic zirconia. Material and Methods One hundred and thirty five zirconia bar specimens (width-length-thickness = 10×20×1.5 mm) were prepared from yttria-stabilized tetragonal zirconia polycrystalline (Y-TZP) ceramic and randomly divided into nine groups to be sintered at different temperatures [decreasing- (SD, 1350°C), regular- (SR, 1450°C), and increasing- (SI, 1550°C) sintering temperature] and different sintered-holding times [shortening- (HS, 60 min), regular- (HR, …