BACKGROUND The thermal expansion of the investment can be restricted by the metal casting ring because the thermal expansion of the ring is less than that of the investment. The ringless casting procedure is in use in clinical dentistry, though there is little scientific data to support its use in fixed partial dentures. In this study, marginal discrepancy of castings produced with the ringless...

Bending property of Ti-Ni alloy dental castings was evaluated in comparison with that of Co-Cr alloy in a cantilever test. Heat treatment effect on the bending property was also investigated in relation to phase transformation. Ti-50.85Ni (mol%) alloy was used, and the shape of bending test specimens was half-rounded in cross section, 2.0mm in diameter. The bending test was carried out at 310K....

Titanium is an ideal material for use in prosthodontics because of its biocompatibility, corrosion resistance, and mechanical strength combined with its lightweight. Recently the use of titanium and titanium alloys for fixed restorations has increased substantially, mainly due to the improvement of techniques for the casting titanium and its alloys. This article reviewed the studies on titanium...

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...

A two-year program was conducted to develop and commercially manufacturing technologies to: • Enable significant reductions in the costs of castings, • Increase the complexity and dimensional accuracy of castings, and • Reduce the development times for delivery of high quality castings. implement selected casting The industry-led R&D project was cost shared with NASA's Aerospace Industry Techno...

The Vickers hardness of the cross-sectioned area of titanium castings made from an experimental resin-bonded calcia investment and three commercial investments was evaluated. The microstructure and element distribution of the surface zone were analyzed using an EPMA. The results showed that the high hardness of the casting surface could be decreased using the experimental investment. The hardne...

To evaluate a Ni-43.5wt%Ti alloy as a new alloy for cast clasp, the fatigue properties of its castings were examined and compared with those of Co-Cr and Type IV Au alloys castings. The Ni-Ti alloy was cast into a phosphate-bonded investment mold using an argon-arc melting and pressure casting machine. The Ni-Ti alloy castings showed superelasticity in bending tests. Fatigue tests were carried ...

Increasing use of aluminum shape castings in automotive and aerospace industries has drawn great attention to fatigue properties of cast aluminum components. The fatigue resistance of aluminum castings strongly depends upon the presence of casting flaws and characteristics of microstructural constituents. The existence of casting flaws significantly reduces fatigue crack initiation life. In the...

Patients who cannot tolerate total coverage of the hard palate or whose maxillary arches are poorly formed, because of congenital, developmental or surgical defects, may be unable to wear a conventional complete denture. These patients can be successfully treated with implant-supported prostheses that cover only a minimal amount of palatal tissue. With spark-eroded castings, very precise restor...

-In this paper a three-phase model (liquid, solid and gas) of the mushy zone for investigation of porosity formation in solidifying castings is developed. This model takes into account the release of the dissolved gas from the alloy as well as heat transfer and interdendritic fluid flow in the mushy zone. An important aspect of this work is related to accounting for the term describing porosity...