COMPARISON OF SHEAR BOND STRENGTHS OF 2 RESIN LUTING SYSTEMS FOR A BASE AND A HIGH NOBLE-METAL ALLOY BONDED TO ENAMEL

Researchers are investigating the use of noble metals for the fabricat ion of resin-bonded prostheses because of concerns about health hazard s of nickel and beryllium in base metal alloys. Tin-plating has been a dvocated to improve the bond of resin luting agents to noble metal all oys. Some manufacturers have suggested that tin-plating is unnecessary to bond noble metal alloys to etched enamel with their products. In t his study, Rexillium base metal and Olympia noble metal alloy specimen s were bonded to extracted human teeth with the use of two resin lutin g agents (F21 and Panavia OP). One third of the noble metal specimens were tin-plated, one third were oxidized, and one third were oxidized and sandblasted. Each of the bonded specimens were thermocycled and su bjected to a shear force until bond failure. The base metal specimens bonded with Panavia OP luting agent exhibited the greatest mean shear bond strengths. The tin-plating surface treatment significantly increa sed the mean shear bond strengths of Olympia noble metal specimens.