R R Wang1, K K Fung. 1. Department of Restorative Dentistry, School of Dentistry, Case Western Reserve University, Cleveland, Ohio, USA.
Abstract
STATEMENT OF PROBLEM: Titanium-ceramic bonding is an unsolved problem for the current use of titanium-ceramic restorations. PURPOSE: The purpose of the study was to characterize oxide formation on titanium surfaces at porcelain sintering temperatures and to determine the effect of chromium coating methods on titanium oxide formation. MATERIAL AND METHODS: Sputter coating and electroplating methods of chromium application were compared and combined. RESULTS: Porous, weak titanium oxide formation on uncoated samples was demonstrated at porcelain sintering temperatures. Groups with chromium coating as an oxygen diffusion barrier exhibited lower oxidation rates, except samples coated by sputtering alone. Temperature effect was found to have the greatest significance on titanium oxidation rate. The overall lowest oxidation rate was located in the group that had chromium coating by the combined coating method and was oxidized at 750 degrees C. CONCLUSION: The electroplating method requires further investigation and development so that a uniform chromium layer can be deposited on titanium.
STATEMENT OF PROBLEM: Titanium-ceramic bonding is an unsolved problem for the current use of titanium-ceramic restorations. PURPOSE: The purpose of the study was to characterize oxide formation on titanium surfaces at porcelain sintering temperatures and to determine the effect of chromium coating methods on titanium oxide formation. MATERIAL AND METHODS: Sputter coating and electroplating methods of chromium application were compared and combined. RESULTS: Porous, weak titanium oxide formation on uncoated samples was demonstrated at porcelain sintering temperatures. Groups with chromium coating as an oxygen diffusion barrier exhibited lower oxidation rates, except samples coated by sputtering alone. Temperature effect was found to have the greatest significance on titanium oxidation rate. The overall lowest oxidation rate was located in the group that had chromium coating by the combined coating method and was oxidized at 750 degrees C. CONCLUSION: The electroplating method requires further investigation and development so that a uniform chromium layer can be deposited on titanium.