Improvement of bond strength in metal-ceramic systems using a gold intermediate layer.
The mechanism of bonding between metal and ceramic in systems using the functionally graded method with pure gold and gold mixture as a primer was examined. Four types of samples, porcelain, porcelain-gold, porcelain-metal and porcelain-gold-metal were prepared. The gold intermediate layer was fired at 1000 degrees C. For porcelain and metal, low-fusing opaque, body porcelain and palladium alloy were used. The intermediate layer was composed of three layers; pure gold, gold-palladium and gold-porcelain layer. During the bending test of each sample, the porcelain peeled away from the porcelain-metal system, while porcelain with the gold intermediate layer remained on the metal surface even after maximal loading. The bond strength of the porcelain-gold-metal system was much higher than that of the porcelain-metal system, and the toughness of the former was much greater than that of the latter. Laser microscopy and scanning electron microscopy (SEM) showed a smooth interface between the intermediate layer and the metal which suggested proper chemical bonding, and no gap was observed. At the interface between the porcelain and the gold intermediate alloy, a good mechanical anchor lock was observed. Electron probe microanalysis (EPMA) showed a clear distribution of each element (e.g. Si, Au and Pd) in the porcelain, gold intermediate layer and metal frame.
Okazaki
M
M
Osaka University Faculty of Dentistry, Japan.
Wang
X
X
Toguchi
M S
MS
Taira
M
M
Takahashi
J
J
Matsuo
C
C
Hino
Y
Y
D001840:Dental Bonding / Q000379:methods; D003776:Dental Porcelain / Q000737:chemistry; D004577:Electron Probe Microanalysis; D006046:Gold / Q000032:analysis / Q000737:chemistry; D006047:Gold Alloys / Q000737:chemistry; D008422:Materials Testing; D016876:Metal Ceramic Alloys / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D010165:Palladium / Q000032:analysis / Q000737:chemistry; D018583:Pliability; D013718:Tensile Strength
D006047:Gold Alloys; D016876:Metal Ceramic Alloys; D003776:Dental Porcelain; D010165:Palladium; D006046:Gold