EMAIL THIS PAGE TO A FRIEND

The New Zealand dental journal

Microstructural analysis of Co-Cr dental alloy at the metal-porcelain interface: a pilot study.


PMID 25597194

Abstract

The purpose of the study was to observe whether conventional porcelain firings had an effect on the underlying microstructure of cobalt-chromium alloys used in porcelain-fused-to-metal systems. One as cast (non-veneered) and two porcelain veneered Co-Cr specimens layered with and without tungsten(W)-metal conditioner were manufactured and analysed. Electron backscatter diffraction was used to determine the crystal structures and grain size across the porcelain-fused-to-metal interface. No difference was found in the microstructure of the alloy in both with and without W-metal conditioner. For the porcelain fired specimens, disparately sized granular structures were observed adjacent to the metal-porcelain interfaces compared to the bulk of the metal. Ellipsoid shaped grains at the alloy surface ranged between 1-11 μm in diameter and averaged 2.70 μm (SD: 2.17 μm) for the specimen layered with W-metal conditioner and 2.86 μm (SD: 1.85 μm) for the specimen layered without W-metal conditioner. Grains located in the bulk were > 200 μm with dendritic-like features. The depth of the fine grain structure adjacent to the surface had an average depth of 15 μm. The crystal structure of the surface layer was found to be predominantly hexagonal close-packed whereas the underlying bulk was a mixture of both face-centered cubic and hexagonal close-packed phases. For the as cast specimen, similar large grains of over 200 μm was observed but exhibited no dendritic like features. In addition, no fine grains were observed at the surface region of the as cast alloy. Conventional porcelain firings altered the interfacial and bulk microstructure of the alloy while the presence of the W-metal conditioner had no influence on the underlying alloy microstructure.

Related Materials

Product #

Image

Description

Molecular Formula

Add to Cart

357189
Tungsten, foil, thickness 0.5 mm, ≥99.9% trace metals basis
W
267546
Tungsten, foil, thickness 0.25 mm, ≥99.9% trace metals basis
W
357197
Tungsten, foil, thickness 0.127 mm, ≥99.9% trace metals basis
W
267538
Tungsten, foil, thickness 0.05 mm, ≥99.9% trace metals basis
W
267511
Tungsten, powder, 12 μm, 99.9% trace metals basis
W
357421
Tungsten, powder, 10 μm, ≥99.99% trace metals basis
W
510106
Tungsten, powder (monocrystalline), 0.6-1 μm, ≥99.9% trace metals basis
W
276324
Tungsten, rod, diam. 4.0 mm, 99.99% trace metals basis
W
267562
Tungsten, wire, diam. 1.0 mm, 99.99% trace metals basis
W
267554
Tungsten, wire, diam. 0.25 mm, ≥99.9% trace metals basis
W
356972
Tungsten, wire, diam. 0.5 mm, ≥99.9% trace metals basis
W
767522
Tungsten, sputtering target, diam. × thickness 2.00 in. × 0.25 in., 99.95% trace metals basis
W
GF12269998
Tungsten, wire reel, 10m, diameter 0.08mm, clean, 99.95%
W
GF81410509
Tungsten, wire reel, 10m, diameter 0.08mm, gold plated, 99.95%
W
GF09514830
Tungsten, wire reel, 10m, diameter 0.125mm, clean, 99.95%
W
GF02629571
Tungsten, foil, 0.5m coil, thickness 0.035mm, coil width .5mm, as rolled, 99.95%
W
GF35593555
Tungsten, foil, 0.5m coil, thickness 0.05mm, coil width 2mm, as rolled, 99.95%
W
GF90049574
Tungsten, foil, 0.5m coil, thickness 0.2mm, coil width .6mm, as rolled, 99.95%
W
GF83538490
Tungsten, foil, 1m coil, thickness 0.02mm, coil width .1mm, as rolled, 99.95%
W
GF60432207
Tungsten, foil, 1m coil, thickness 0.05mm, coil width .51mm, as rolled, 99.95%
W
GF91197748
Tungsten, foil, 1m coil, thickness 0.1mm, coil width .6mm, as rolled, 99.95%
W
GF99741741
Tungsten, foil, 2m coil, thickness 0.025mm, coil width .7mm, as rolled, 99.95%
W
GF66018999
Tungsten, foil, 2m coil, thickness 0.04mm, coil width 0.7mm, as rolled, 99.95%
W
GF17648589
Tungsten, foil, 2m coil, thickness 0.1mm, coil width .6mm, as rolled, 99.95%
W
GF18728961
Tungsten, microfoil, disks, 25mm, thinness 0.1μm, specific density 182μg/cm2, permanent mylar 3.5μm support, 99.95%
W
GF22706210
Tungsten, rod, 1000mm, diameter 5.0mm, centerless ground, 99.95%
W
GF01295502
Tungsten, rod, 100mm, diameter 20.0mm, centerless ground, 99.95%
W
GF30443554
Tungsten, rod, 18mm, diameter 20.0mm, centerless ground, 99.95%
W
GF33990273
Tungsten, rod, 200mm, diameter 3.0mm, centerless ground, 99.95%
W
GF38415023
Tungsten, rod, 500mm, diameter 10.0mm, centerless ground, 99.95%
W