BONDING CHARACTERISTICS OF LOW-FUSING PORCELAIN BONDED TO PURE TITANIUM AND PALLADIUM-COPPER ALLOY

This study compared bond strengths among palladium-copper alloy/VMK 68 porcelain, cast titanium/Duceratin porcelain, and machine-milled titanium/Procera porcelain combinations and investigated the mode of bond failure of these combinations. The effect of multiple firings on the bond strength of porcelain bonded to machine-milled pure titanium was then examined. A uniform thickness of 1 mm of porcelain was applied along an 8 mm length in the central portion of metal specimens measured 25 x 3 x 0.5 mm. The specimens were subjected to a three-point bending test on a load-testing machine with a span distance of 20 mm, and the load of bond failure was recorded and statistically analyzed. Two completely debonded specimens and two longitudinally sectioned specimens of each group were studied with a scanning electron microscope to determine the mode of bond failure. The bond strength of Pd-Cu/VMK 68 porcelain was significantly greater than two titanium/porcelain combinations. There was no significant difference in the bond strengths of porcelain bonded to machine-milled pure titanium among the five porcelain firing schedules.