This experimental study was done on extracted human teeth to compare the fracture and deformation of the two rotary endodontic files system namely K-3 and Protapers. It was conducted at the dental clinics of the Aga Khan University Hospital, Karachi, A log of file deformation or fracture during root canal preparation was kept. The location of fracture was noted along with the identity of the ca...

The fracture and crack growth of mechanical structures is a usual phenomenon which is due to the application of tensile, cyclic loading or thermal stresses on the structure. So introducing of methods to prevent the crack growth is useful. Afterward, one of the repairing methods of crack growth, consisting to make a hole in the crack tip to elimi-nate the sharp corners, was explained. This metho...

Optimising the results of fracture treatment requires a holistic view of both patients and treatment. The nature of the patient determines the priority targets for outcome, which differ widely between the elderly and the young, and between the victims of high and low energy trauma. The efficacy of treatment depends on the overall process of care and rehabilitation as well as the strategy adopte...

PURPOSE The purpose of this study was to investigate the fracture loads and mode of failure of all-ceramic crowns fabricated using Top-Ceram and compare it with all-ceramic crowns fabricated from well-established systems: IPS-Empress II, In-Ceram. MATERIALS AND METHODS Thirty all-ceramic crowns were fabricated; 10 IPS-Empress II, 10 In-Ceram alumina and 10 Top-Ceram. Instron testing machine w...

In order to characterize the fatigue behaviour and determine the fracture energy of polysilicon used in micro-systems, an on-chip testing device has been designed and fabricated. The experimental set-up is able to continuously measure the elastic stiffness decrease and therefore to evidence fatigue of polysilicon 15-μm thick films and to allow for the introduction of a sharp crack at the notch ...

While fracture is generally considered to be undesirable in various manufacturing processes, delicate control of fracture can be successfully implemented to generate structures at micro/nano length scales. Fracture-based fabrication techniques can serve as a template-free manufacturing method, and enables highly-ordered patterns or fluidic channels to be formed over large areas in a simple and ...

Stent fracture is a rare complication of drug-eluting stent implantation with a reported rate of 0.84%-3.2% in various clinical studies with first-generation drug-eluting stents and 29% in autopsy studies. Sirolimus-eluting stents with their closed cell design were reported to be more prone to fracture compared to paclitaxel-eluting stents. Other risk factors for stent fracture are multiple ste...

Combining several materials to create a structural system has led to a new kind of application previously not possible with conventional materials. Examples are FRP and its strengthening system. Nonetheless, the existence of the interface between two substrates introduces a challenging problem in determining durability of bond systems. In many applications, the durability of individual material...

this report presents a 3.5-year-old boy who was hospitalized for limping. medical history and physical exams were not suggestive for any definitive diagnosis. laboratory and radiographic exams did not support any specific diagnosis either. subsequently bone scan was performed and increased activity in the ankle due to cuboid fracture was incidentally observed.