o bjectives: headgears are among the effective orthodontic appliances to achieve treatment goals. unilateral molar distal movement is sometimes needed during an orthodontic treat- ment, which can be achieved by an asymmetric headgear. different unilateral headgears have been introduced. the main goal of this study was to analyze the force system of uni- lateral expanded outer bow asymmetric hea...

introduction: the fracture strength of endodontically treated teeth compared to vital ones has long been a source of controversy. it is not clear how root canal therapy affects the stress distribution in teeth. the purpose of this study was to evaluate the changes in stress distribution after root canal therapy in a human maxillary canine by finite element analysis (fem). materials and methods:...

modelling of crack propagation by finite element method under mixed mode conditions is of prime importance in fracture mechanics. this paper describes an application of finite element method to the analysis of mixed mode crack growth in linear elastic fracture mechanics. crack growth process is simulated by an incremental crack-extension analysis based on the maximum principal stress criterion,...

condition monitoring of bldc motors due to their important applications is gaining more and more significance. rotor eccentricity is one of the most important sources of faults in these motors. up to now, detection methods of this fault under nonstationary conditions are limited to complicated and time-consuming methods using wavelets and cohen class algorithms which are difficult to implement ...

objectives: this study sought to assess the effects of length and inclination of implants on stress distribution in an implant and terminal abutment teeth in an implant assisted-removable partial denture (rpd) using three-dimensional (3d) finite element analysis (fea).   materials and methods: in this in vitro study, a 3d finite element model of a partially dentate mandible with a distal extens...

o bjectives: the aim of this study was to investigate the displacement and stress distri- bution during surgically assisted rapid maxillary expansion under different surgical conditions with tooth- and bone-borne devices. materials and methods: three-dimensional (3d) finite element model of a maxilla was constructed and an expansion force of 100 n was applied to the left and right molars and pr...

background and aims. there are many edentulous people with severely resorbed residual ridges and non-resilient lining mucosa that are unable to tolerate occlusal forces during functional and parafunctional movements. lining the tissue surface of dentures with a flexible material can theoretically distribute and absorb forces with cushioning effect. the aim of this study was to evaluate the effe...

background and aims. the purpose of this study was to evaluate initial force and force decay of commercially available elastomeric ligatures and elastomeric separators in active tieback state in a simulated oral environment. materials and methods. a total of 288 elastomeric ligatures and elastomeric separators from three manufacturers (dentaurum, rmo, 3m unitek) were stretched to 100% and 150% ...

distal extension removable partial denture is a prosthesis with lack of distal dental support with a 13-fold difference in resiliency between the mucosa and the periodontal ligament, resulting in leverage during compression forces. it may be potentially destructive to the abutments and the surrounding tissues. the aim of this study was to assess the effect of implant location on stress distribu...

in saturated soils, heating induces thermal expansion of both grains and the pore fluid. lower thermal expansion coefficient of aggregates results in the increase of pore pressure and reduction of the effective stress besides subsequent volume changes due to the dissipation of pore pressure and heat transfer. dissipation of thermally induced pore pressure with time is a coupled thermo-hydro-mec...