Search results for "Gold alloys"
showing 4 items of 4 documents
Density functional theory description of random Cu-Au alloys
2019
Density functional alloy theory is used to accurately describe the three core effects controlling the thermodynamics of random Cu-Au alloys. These three core effects are exchange correlation (XC), local lattice relaxations (LLRs), and short-range order (SRO). Within the real-space grid-based projector augmented-wave (GPAW) method based on density functional theory (DFT), we adopt the quasinonuniform XC approximation (QNA), and take into account the LLR and the SRO effects. Our approach allows us to study the importance of all three core effects in a unified way within one DFT code. The results demonstrate the importance of the LLR term and show that going from the classical gradient level a…
Retentive strengths of cast gold crowns using glass ionomer, compomer, or resin cement
1998
The retention forces of a newly developed compomer cement (Dyract Cem), a glass ionomer cement (Ketac Cem Aplicap), and a resin cement (F21) were examined.Cemented cast gold crowns were removed along the path of insertion with a Zwick universal testing device. The impact of both a cured and a noncured additional bonding layer that were applied to the inner surface of the crowns was examined across the Dyract Cem group.The mean adhesive strength was measured at 2.36 +/- 0.69 N/mm2 in the Ketac Cem group, at 0.60 +/- 0.28 N/mm2 in the F21 group, and at 1.85 +/- 0.94 N/mm2 in the Dyract Cem group, respectively. The application of an additional bonding layer to the inner surface of the crowns d…
Zirconia Removable Telescopic Dentures Retained on Teeth or Implants for Maxilla Rehabilitation. Three-Year Observation of Three Cases
2010
Abstract This report addresses maxillary restoration with removable telescopic crown-retained palatal free dentures. One patient with 7 natural teeth (PERIO), a second patient with 6 dental implants (IMPL), and a third patient with 2 natural teeth and 4 dental implants (IMPL-PERIO) were treated. Zirconia copings for natural teeth and individual zirconia implant abutments were fabricated in CAD/CAM and used as primary crowns. Electroformed gold copings were used as secondary telescopes. All maxilla supraconstructions were fabricated with zirconia and CAD/CAM. Patients were monitored during a 3-year period; all teeth and implants survived, and no biological or mechanical complications occurre…