OBJECTIVES The present study was designed to test the null hypothesis that there is no difference in the fracture resistance of pulpless teeth restored with different types of post-core systems and full coverage crowns. METHODS Extracted human upper premolars were restored with a fiber post, prefabricated metallic post or cast metallic post-core. Teeth with full crown preparations without pos...

BACKGROUND Many clinical observations have shown that immediate loading is indicated when the stabilization of the bone/implant is optimal and when the estimated loads are not excessively high. Nonetheless, more experimental studies are needed to consider the immediate loading protocol as a safe procedure. Mechanical analysis using the finite element (FE) method analysis has been employed by ma...

BACKGROUND The Bagby and Kuslich (BAK) cage as posterior lumbar interbody fusion (PLIF) is reported to give satisfactory results in restoring spinal stability. Moreover, correction by obliquely inserting a single BAK cage has the advantages of reducing exposure, precise implantation, and lower cost. However, biomechanical data on this procedure are not abundant. This study was designed to compa...

introduction: many studies have been performed to evaluate the stress distribution around endodontic posts; those which compared posts composed of different materials are rare. the aim of this study was to compare stresses induced in dentin by three structurally different posts using photoelasticity method. materials and methods: nine blocks of psm-5 photoelastic material with 45×45×10 mm dimen...

extended interaction oscillators (eio) are vacuum electronic sources of microwave, millimeter-wave and terahertz radiations. in this paper, eio is investigated by using a circuit model. the value of the coupling element in the model is evaluated from the near band-edge dispersion characteristics of the rf structure. the end external loading of the interaction structure is equivalently modeled b...

In breast cancer radiotherapy, the internal mammary lymphatic chain is treated in the target volume in a group of patients with high risk criteria. There are a number of different techniques in breast radiotherapy because of the variability of the anatomic region, structures and risk criteria in the irradiation field. When irradiating the target volume we also consider homogeneity of dose distr...

BACKGROUND Subtrochanteric oblique osteotomy (SOO) has been widely used to reconstruct highly dislocated hips in uncemented total hip arthroplasty. The occurrence of complications can be attributed to the instability of the osteotomy region. The aim of this study was to evaluate the initial stability of SOO in uncemented total hip arthroplasty. MATERIAL AND METHODS A 3-dimensional finite elem...

The goal of this study was to quantify the relative contributions of each muscle group surrounding the spine to vertebral joint rotational stiffness (VJRS) during the push-up exercise. Upper-body kinematics, three-dimensional hand forces and lumbar spine postures, and 14 channels (bilaterally from rectus abdominis, external oblique, internal oblique, latissimus dorsi, thoracic erector spinae, l...

Objectives: The study used three-dimensional finite element analysis to evaluate the effects of total deformation and Von Mises stresses (VMS) different shaped non-carious cervical lesions (NCCLs) occluso-gingival dimensions (OGD) maxillary premolars when restored with restorative materials. Methods: Maxillary premolar was scanned utilizing 3D-laser scanning produce a 3D digital geometrical mod...