In this paper we propose a computationally efficient method for the steering of flexible needles with a bevel tip in the presence of uncertainties for the case when there are no obstacles in the environment. Based on the stochastic model for the needles, we develop a new framework for path planning of a flexible needle with a bevel tip. This consists of three parts: (a) approximation of probabi...

Based on the comprehensive analysis of previous research about the spiral bevel and hypoid gear, principle of forming spherical involute tooth surface was proposed with the spherical involute that was new theory applied in the field of their modeling. According to precise shape of tooth surfaces, each part of the quick and accurate derivations of the basic parametric equation of the tooth profi...

In this study, an optimization methodology is presented to systematically define head-cutter geometry and machine tool settings to introduce optimal tooth modifications in spiral bevel and hypoid gears. The goal of the optimization is to simultaneously minimize the tooth contact pressure and the angular displacement error of the driven gear (the transmission error), to maximize the elastohydrod...

Objectives. To investigate the influence of a contra bevel on the fracture resistance of teeth restored with cast post and core. Materials and Methods. Sixty plastic analogues of an upper incisor were endodontically treated and prepared with 6° internal taper and 2 mm of ferrule in order to receive a cast post and core. The prepared samples were divided into two groups (n = 30); the first group...

The purpose of this study was to test the hypothesis that increased masticatory muscle accompanied morphologic changes in the temporal bone and squamosal suture. Ten mice deficient for the protein myostatin (Mstn -/-) had significantly increased skeletal muscle mass and were compared with nine controls (Mstn +/+). Variables measured include linear and areal metrics describing temporal size and ...

AIM The aim of this study was to compare the marginal leakage of hybrid and microfilled composite resin in Class V restorations with and without an enamel bevel. METHODS AND MATERIALS Fifty-six cavities were prepared on the buccal and lingual surfaces of 28 extracted human molars using a round bur with the dimensions of 3 x 2 x 1.5 mm. The specimens were divided into two groups of 28 based on...

In this paper, we present a system capable of automatically steering a bevel-tipped flexible needle under ultrasound guidance toward a physical target while avoiding a physical obstacle embedded in gelatin phantoms and biological tissue with curved surfaces. An ultrasound pre-operative scan is performed for three-dimensional (3D) target localization and shape reconstruction. A controller based ...

The aim of this retrospective study was to compare the outcome of surgical endodontic treatment preformed using the traditional versus modern techniques. There were 110 patients who were treated by surgical endodontic treatment between 2000 and 2002 and evaluated from their dental charts. The surgical endodontic treatment was preformed using a traditional or modern technique. The traditional te...