Bone tissue and geometry are constantly modified through modeling and remodeling at the periosteal, endosteal and intracortical envelopes. Results from several studies indicate that femoral bone geometry is a predictor of whole bone strength (e.g. femoral neck strength), however, it is not known whether there is a relationship between bone structural and material properties. Bone geometry can b...

The mechanical interaction between the surgical tools and the target soft tissue is mainly dictated by the fracture toughness of the tissue in several medical procedures, such as catheter insertion, robotic-guided needle placement, suturing, cutting or tearing, and biopsy. Despite the numerous experimental works on the fracture toughness of hard biomaterials, such as bone and dentin, only a ver...

Glass ionomer cements show great potential as low cost, minimally invasive dental restorative materials. However, their use is limited by relatively poor mechanical properties, especially fracture toughness. One possibility for improving their fracture toughness is through the addition of fluorhydroxyapatite nanoparticles, which resemble the crystals found in tooth enamel. Hydroxyapatite and fl...

A 0.4C-2Si-1Cr-1Mo steel with an ultrafine elongated grain (UFEG) structure and an ultrafine equiaxed grain (UFG) structure was fabricated by multipass caliber rolling at 773 K and subsequent annealing at 973 K. A static three-point bending test was conducted at ambient temperature and at 77 K. The strength-toughness balance of the developed steels was markedly better than that of conventionall...

INTRODUCTION Polymer brackets still have some disadvantages because of decreased wear resistance and hardness. The aim of this study was to investigate the mechanical properties of alternative bracket polymers; urethane-dimethacrylate, high-density polyethylene, and an experimental bracket polymer (EBP) consisting of polyethylene and a copolymer were tested. Polycarbonate and polyoxymethylene b...

To study the effect of different cooling rates after glaze firing on Radius of radial crack, Fracture toughness and Microhardness of Alumina reinforced porcelain. Total 30 porcelain discs reinforced with aluminium oxide of 8mm diameter×0.6mmthickness were prepared. Specimens were divided into three groups, each group containing ten discs. They were positioned at the entrance of the furnace with...

An understanding of the evolution of toughness is essential for the mechanistic interpretation of the fracture of cortical bone. In the present study, in vitro fracture experiments were conducted on human cortical bone in order to identify and quantitatively assess the salient toughening mechanisms. The fracture toughness was found to rise linearly with crack extension (i.e., rising resistance-...

A series of 18 Ni (300 grade) maraging steels of overall commercial purity but containing also deliberate impurity additions of sulphur, phosphorus, carbon, chromium and silicon + manganese has been studied. The fracture toughness and stress-corrosion resistance (determined using planestrain fatigue-precracked specimens tested in 3. 5% sodium chloride solution) of these steels have been compare...

Toughening mechanisms based on the presence of collagen fibrils have long been proposed for mineralized biological tissues like bone and dentin; however, no direct evidence for their precise role has ever been provided. Furthermore, although the anisotropy of mechanical properties of dentin with respect to orientation has been suggested in the literature, accurate measurements to support the ef...

Interlaminar fracture mechanics has proven useful for characterizing the onset of delaminations in composites and has been used with limited success primarily to investigate onset in fracture toughness specimens and laboratory size coupon type specimens. Future acceptance of the methodology by industry and certification authorities however, requires the successful demonstration of the methodolo...