OBJECTIVES To assess the effect of interfacial surface roughness on the flexure strength and fracture mode and origin utilizing an in-vitro assessment of the clinical failure conditions expected for all-ceramic crowns and the connector area of fixed partial dentures (FPDs) using bilayered ceramic specimens tested in bi-axial flexure. METHODS Sets of 20 bilayered composite discs, with core:den...

The aim of this study was to investigate the fracture strength of endodontically treated teeth restored with different posts and variable ferrule heights. Sixty freshly extracted human canines were treated endodontically and randomly assigned to 6 groups (n=10), being restored with custom-made cast post-and-core (CP0 and CP3 groups), prefabricated post and composite resin core (PF0 and PF3 grou...

Observations of natural fractures in core or image logs typically give limited information on orientation, aperture and intensity. Because of the sparseness of wellbore intersections of fractures, data analysis results in incomplete statistical characterization of the fracture population, leaving interwell characterization almost impossible. Using basic fracture mechanics models and a novel cor...

It has long been observed that brittle fracture of materials can lead to emission of high energy electrons and UV photons, but an atomistic description of the origin of such processes has lacked. We report here on simulations using a first-principles-based electron force field methodology with effective core potentials to describe the nonadiabatic quantum dynamics during brittle fracture in sil...

OBJECTIVE To report on a case of a pathological burst fracture in the cervical spine where typical core red flag tests failed to identify a significant lesion, and to remind chiropractors to be vigilant in the recognition of subtle signs and symptoms of disease processes. CLINICAL FEATURES A 61-year-old man presented to a chiropractic clinic with neck pain that began earlier that morning. Aft...

background and aims. one of the major problems of all-ceramic restorations is their probable fracture under occlusal force. the aim of the present in vitro study was to compare the effect of two marginal designs (chamfer and deep chamfer) on the fracture resistance of all-ceramic restorations, cercon. materials and methods. this in vitro study was carried out with single-blind experimental tech...

The cohesive element approach is proposed as a tool for simulating delamination propagation between a facesheet and a core in a honeycomb core composite panel. To determine the critical energy release rate (Gc) of the cohesive model, Double Cantilever Beam (DCB) fracture tests were performed. The peak strength (σc) of the cohesive model was determined from Flatwise Tension (FWT) tests. The DCB ...