Recently, new generations of nanoceramic composite resin CAD/CAM blocks, have been introduced to dentistry, which are claimed to have higher flexural strength, fracture, fatigue and wear resistance, and beside natural looking appearances can be polished easily. Therefore, the aim of this study was to compare flexural strength of 2 nanoceramic composite resin CAD/CAM blocks (Lava Ultimate and Vi...

Resistance to cyclic flexural fatigue failure is an important feature of rotary nickel-titanium (NiTi) instruments. The aim of this study was to evaluate the cyclic flexural fatigue failure resistance of RevoS Shaper Universal rotary NiTi files and to compare it to two other rotary NiTi files with similar size and taper, the Hero Shaper and the ProFile. Fifteen each of Revo-S Shaper Universal, ...

The limitations of the current clinical options for valve replacements have inspired the development of enabling technologies to create a tissue engineered heart valve (TEHV). Poly(ethylene glycol) diacrylate (PEGDA) hydrogel scaffolds permit greater biological and biomechanical customization than do non-woven mesh scaffold technologies. However, the material characterization of PEGDA hydrogels...

Flexural fatigue tests are typically run under displacement or in a straincontrolled mode. In these tests, either the oscillatory displacement amplitude or strain amplitude applied to the bottom of the specimen is kept constant. The evolution of loading required to cause fatigue is then measured. Load amplitude decreases with the number of cycles, and the specimen is considered to have failed w...

OBJECTIVE To determine the effects of whitening strips on bovine dentin fatigue resistance and flexural strength in vitro. MATERIALS AND METHODS A total of eighty bovine dentin specimens (2x2x17mm) were treated with either: control glycerine gel on plastic film wrap or whitening strips containing 9.5% hydrogen peroxide. Treatment was applied for 30 minutes, twice a day, for 1- or 4-weeks. Aft...

In this thesis, an analytical tool for predicting fatigue performances of RC bridge slabs isdeveloped based on the concept of fracture mechanics. The degradation of bridging stress in thenormal direction of concrete cracks is considered as a primary mechanism for the propagation ofboth flexural cracks and shear cracks that induce the failure of RC slabs. The analysis of RC slabs...

Analytical models that predict modulus degradation in cortical bone subjected to uniaxial fatigue loading in tension and compression are presented. On the basis of experimental observations, damage was modeled as self-limiting for tension but not for compression. These mechanistic uniaxial damage models were then developed into a model for flexural fatigue of cortical bone based on laminated be...

This paper aims to clarify the effect of steel fiber on the flexural toughness of the high performance concrete containing fly ash and nano-SiO2. The flexural toughness was evaluated by two methods, which are based on ASTM C1018 and DBV-1998, respectively. By means of three-point bending method, the flexural toughness indices, variation coefficients of bearing capacity, deformation energy, and ...