Abstract: During solidification and casting in metallic molds, the heat flow is controlled by the thermal resistance at the casting-mold interface. Thus heat transfer coefficient at the metal- mold interface has a predominant effect on the rate of heat transfer. In some processes such as low pressure and die-casting, the effect of pressure on molten metal will affect the rate of heat transfer a...

Casting failures of alloys in dental technology should be the exception, not the rule. They have to be detected in time and associated with possible causes. For the experimental part base metal alloys single tooth restorations were achieved using the conventional lost wax process for casting in order to be evaluated. Some casting defects obtained during the experimental part are exemplified: in...

This study commences by performing an experimental investigation to measure the temperature distribution within a casting system comprising a cylindrical aluminum casting and a green-sand mold. The experimental temperature measurements are then used to compute the effective heat transfer coefficient at the mold/metal interface using four different formulae. In the temperature measurement, a sym...

The success of metal-ceramic restorations depends on an optimal bond between metal and ceramic. This study evaluated the effect of 3 casting atmospheres on the metal-ceramic bond strength (MCBS) of 2 Ni-Cr alloys, with beryllium (Fit Cast V) and without beryllium (Fit Cast SB). Sixty acrylic resin patterns (8 mm long and 5 mm diameter) were obtained using a fluorocarbon resin matrix. Wax was us...

Although an all-ceramic restoration is increasingly in use in dentistry, a conventional metal ceramic restoration is still considered to be a gold standard. However, with increasing demand in esthetics and advances in ceramic technology, future of metal ceramic restoration has been less certain, necessitating additional qualities in terms of superior esthetics and easy fabrication. A ceramic-pr...

conclusions the castings fabricated from the ringless technique with non-precious alloy are acceptable. this investing system is useable for the fabrication of fixed restorations. results after statistical evaluation, the following results were obtained: the mean vertical margin discrepancy for conventional investing was 156.72 ± 64.67µ; for the ringless technique it was 117.3 ± 26.77µ; and for...

In dentistry, gold-based noble metal alloys have traditionally been cast into various types of dental prostheses, such as partial dentures, crowns, and bridges. More recently, less expensive dental alloys with base-metal elements, such as Co-Cr and Ni-Cr, have been used. Titanium is considered to be an attractive alternative to these traditional dental alloys because of its remarkable lack of t...

Background and Aim: Different methods and materials are available for post and core (P&C) fabrication. We aimed to compare the fracture resistance and failure modes of endodontically treated maxillary central incisors restored with six different P&C systems. Materials and Methods: In this in-vitro study, after endodontic treatment and coronal preparation of 60 maxillary central incisors, six d...

There are concerns that tooth bleaching agents may adversely affect dental materials. The aim of this study was to test the hypothesis that increasing concentrations of hydrogen peroxide (HP) are more effective than water at increasing metal ion release from two typical dental casting alloys during bleaching. Discs (n = 28 for each alloy) were prepared by casting and heat treated to simulate a ...