Characteristics and porcelain bond strength of (Ti,Al)N coating on dental alloys.

Abstract

The effect of a novel titanium-aluminum nitride film, or (Ti,Al)N film, on the bond strength between a dental porcelain and two nickel-based dental alloy substrates was investigated. A thin layer of (Ti,Al)N film was deposited on flat metal samples using a reactive radio-frequency sputtering method. A uniform thickness of porcelain was applied to the film- coated metal samples. Metal-ceramic specimens were subjected to three-point bending, and failure loads were recorded. Bond strengths between the porcelain and (Ti,Al)N-coated metal alloys ranged from 159.0 +/- 11.7 N to 278.0 +/- 12.3 N. These values were significantly greater (p< 0.05) than bond strengths recorded for control samples that did not incorporate the (Ti,Al)N film. An electron probe microanalyzer with a line profile mode was used to characterize the interface between the (Ti,Al)N film and the porcelain. Results of this investigation suggest that the (Ti,Al)N film (1) increases the flexural bond strength between dental porcelain and nickel-based alloy substrates by permitting elemental diffusion, (2) interferes with the surface oxide formation that characteristically originates from the nickel-based metal alloy substrate, and (3) provides an appropriate oxide layer for porcelain application.