OBJECTIVE To evaluate the marginal gap (MG) and absolute marginal discrepancy (MD) of full ceramic crowns with two finish line designs, shoulder and chamfer, using microcomputed tomography (micro-CT) before and after cementation. MATERIALS AND METHODS Sixty extracted human maxillary premolar teeth were divided into two groups based on the finish line design: Group I: 90° shoulder and Group II...

OBJECTIVE In this investigation the thickness of enamel in the gingival, middle, and incisal thirds of the labial surface of the anterior teeth were measured regarding preparation of the teeth for porcelain laminate veneers. MATERIALS AND METHODS Part one, 20 extracted intact human maxillary central and lateral incisors ten of each were selected. The teeth were imbedded in autopolimerize acry...

When segmenting three-dimensional medical data using level sets, re-distancing the implicit surface is time-consuming. We propose a fast implementation, based on Chamfer distance, which preserves the interface location. Experiments using synthetic and real data show reasonable accuracy and considerable speed-up. 2005 Elsevier B.V. All rights reserved.

A second-generation automated deburring cell is currently under development at the National Institute of Standards and Technology. This cell will be capable of automatically generating, from part geometry and machining information, a series of robot paths for deburring aerospace parts made from superalloys. In order to compensate for the inaccuracy of robots when following computed coordinates,...

In this letter report, core sediments from the Mt Elbert Stratigraphic Test Well #1 (Mt Elbert) located at Milne Point, Alaska were characterized in situ by high-pressure x-ray diffraction (HXRD). These samples represent part of the 500 ft (152.4 m) of continuous core collected from the D and C sands in the Mikkelson Tongue of the Canning Formation (BOSWELL et al., 2008). Research teams began c...

This paper builds on initial evidence of First Language influence on brass playing presented in Heyne and Derrick (2013) [13] by indicating how tongue positioning might affect trombone timbre. Ultrasound imaging of the tongue was used to compare vowel production and sustained trombone notes for three participants, one each of New Zealand English, Tongan and Japanese, whose musical production wa...

BACKGROUND Ceramic veneer fracture has occurred mainly at the incisal edge of the veneer because of greater stress. This study compares and evaluates the fracture resistance ceramic veneers with three different incisal preparations. MATERIALS & METHODS 15 human permanent maxillary central incisor extracted were selected which were divided into three groups of 5 each having a different Incial ...

The task and design requirements for a vision system for manipulator position sensing in a telerobotic system are described. Model-based analysis-by-synthesis techniques offer generally applicable methods with the potential to meet the system's requirement for accurate , fast and reliable results. Edge-based chamfer matching allows eecient computation of a measure, E, of the local diierence bet...

Journal bearings in typical applications are subjected to misalignment due several causes, such as shaft deformation under load and errors related the installation manufacturing processes. Misalignment has well-known severe negative consequences on performance of bearings. This paper deals with bearing chamfer reduce these misalignment, two forms edge modification considered analysis. These lin...