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...

several appliances have been used for palatal expansion for treatment of posterior cross bite. the purpose of this study was to evaluate the stress induced in the apical and crestal alveolar bone and the pattern of tooth displacement following expansion via removable expansion plates or fixed-banded palatal expander using the finite element method (fem) analysis.two 3d fem models were designed ...

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% ...

background and aims. the aim of this study was to determine the stress patterns within an implant and the effect of different types of connections on load transfer. materials and methods. three different types of implant-abutment connections were selected for this study. sample a: 1.5-mm deep internal hex corresponding to a lead-in bevel; sample b: a tri-channel internal connection; and sample ...

microtubules, the active filaments with tubular shapes, play important roles in a wide range of cellular functions, including structural supports, mitosis, cytokinesis, and vesicular transport, which are essential for the growth and division of eukaryotic cells. finding properties of microtubules is one of the main concerns of scientists. this work helps to obtain mechanical properties of micro...

micro-electro-mechanical systems (mems) are combination of electrical and mechanical components in micron dimensions. in recent years, holding, actuating methods and handling of mems components such asmicrogripper, microsensors and etc. have been deeply studied. microgrippers for handling, positioning andassembling of micro components are very useful so that for clamping need actuation created ...

cold roll-forming is a process in which the roll of sheet is formed by passing continuously through the set of rotary rollers without changing thickness in a cool way until it is formed to the desired profile. in this paper a parametric study on the section twist angle in roll-forming the non-symmetric channel is presented, using finite element simulation. at first finite element simulation res...