Journal of Dental Research, Vol 67, 474-478, Copyright © 1988 by International & American Associations for Dental Research Online Journals
The relationship between oxide adherence and porcelain-metal bonding
J. R. Mackert Jr, R. D. Ringle, E. E. Parry, A. L. Evans and C. W. Fairhurst
Department of Restorative Dentistry, School of Dentistry, Medical College of Georgia, Augusta 30912-0200, USA.
The lack of a reliable bond test has hindered the elucidation of the
mechanism for porcelain-metal bonding in dental systems, because a test
capable of detecting differences among porcelain-metal bonds of various
qualities is required before the reasons for these differences may be
ascertained. A method was developed in the present study whereby specimens
of alloys with differing physical properties may be deformed to a constant
strain to yield a fracture surface suitable for measurement of the area
fraction of retained porcelain by an x-ray spectrometric technique
described previously. The method proved sufficiently discriminating that
significant differences could be found in 48 of the possible 66 comparisons
among alloys and treatments. Linear regression analysis revealed a strong
correlation (r2 = 0.947) between the area fractions of retained porcelain
measured in the present study and the oxide adherence strength values
measured previously. This strong correlation, when considered in light of
the literature evidence for the presence of an oxide layer at the
porcelain-metal interface, provides compelling support for the oxide layer
theory of porcelain-metal bonding in dental alloy systems.
