SPUTTERED OXIDE FOR DENTAL CERAMIC-METAL BOND

THE OBJECTIVE OF THE PROPOSED RESEARCH PROJECT IS TO INVESTIGATE THE USE OF A NOVEL, GRADIENT-COMPOSITION, SPUTTERED-OXIDE FILM FOR IMPROVING THE BONDING BETWEEN METALAND CERAMIC IN PORCELAIN-FUSED-TO-MENTAL DENTAL RESTORATIONS. THE PRESENT PROCESS UTILIZES A DISCRETE OXIDELAYER FORMED BY DIFFUSION AND AN ACCUMULATION OF OXIDE-FORMING ELEMENTS FROM THE BULK OF THE METAL CASTING TOTHE PORCELAIN INTERFACE. THE ALTERNATE TECHNIQUE PROPOSED HERE INVOLVES THE MAGNETRON SPUTTER-DEPOSITION OF LAYER WITH A GRADIENT OXYGENCOMPOSITION THAT SHOULD HAVE SUPERIOR BONDING TO BOTH THE CERAMIC AND METAL COMPONENTS. THE GRADIENT WILL BE ACHIEVED BY SLOWLY VARYING THE GAS COMPOSITION DURING SPUTTERING FROM ARGON TO OXYGEN. THIS WILL RESULT IN A SMOOTH COMPOSITIONAL TRANSITION AND MAY PROVIDE A REDUCTION IN THE UNDESIRABLE RESIDUAL TENSILE STRESSES THAT OCCUR AT SOME PORCELAINMETAL INTERFACES DUE TO THE DIFFERENCE IN THE THERMAL CONTRACTION COEFFICIENTS. THE USE OF THIS PROCEDURE MAY SIGNIFICANTLY IMPROVE THE PORCELAIN-METAL BONDSTRENGTH, PARTICULARLY WITH BASE METAL CASTING ALLOYS, AND IT SHOULD BE LESS TECHNIQUE-SENSITIVE THAN CURRENT DENTAL LABORATORY PROCEDURES.