background and aims. all-on-four technique involves the use of tilted implants to allow for shorter cantilevers. this finite element analysis aimed at investigating the amount and distribution of stress in maxillary bone surrounding the implants with all-on-four vs. frequently used method with six implants technique using different numbers and inclination angles. materials and methods. a 3d ede...

the main goal of this study was to evaluate differences in stress distribution relevant to the number of implants under an anterior bridge when combined with a removable partial denture in the posterior region.four three-dimensional finite element models (3d fem) were designed from a mandible containing an implant-supported bridge extending between canines, and a bilateral distal extension remo...

background and aims. heat generated within tooth during clinical dentistry can cause thermally induced damage to hard and soft components of the tooth (enamel, dentin and pulp). geometrical characteristics of immature teeth are different from those of mature teeth. the purpose of this experimental and theoretical study was to investigate thermal changes in immature permanent teeth during the us...

objective: in all ceramic fixed partial dentures the connector area is a common fracture location. the survival time of three-unit fixed partial dentures may be improved by altering the connector design in regions of maximum tension. the purpose of this study was to determine the effect of buccolingual increase of the connector width on the stress distribution in posterior fixed partial denture...

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:...

Minimizing a polynomial function over a region defined by polynomial inequalities mod4 els broad classes of hard problems from combinatorics, geometry and optimization. New algorithmic 5 approaches have emerged recently for computing the global minimum, by combining tools from real 6 algebra (sums of squares of polynomials) and functional analysis (moments of measures) with semidef7 inite optim...

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% ...

introduction there is a growing interest in determining the concentration of various elements in food spices. in the present study, the instrumental neutron activation analysis (inaa) was employed to measure the trace elements in 11 commonly food spices consumed in tehran, iran. materials and methods the levels of k, mn, na, cl, v, br, al, and as were determined and their effects on human healt...

We investigate iterative implementations of linear receivers for spatial diversity channels. This work has been motivated by recent results concerning iterative implementations of linear multiuser receivers, under the assumption of long random sequences. We explore implementation issues for such iterative methods for f inite system dimensions. We consider the Chebyshev iteration using estimates...