Bond strength studies of precious, semiprecious, and nonprecious ceramic-metal alloys with two porcelains.

One-hundred cylindrical pull-through ceramic-metal test specimens were subjected to shear loading forces. Two porcelain systems were treated in association with five ceramic alloys--one precious, one semiprecious, and three nonprecious alloys. 1. There was no significant difference in bond strength between Ceramco and Vita porcelains. 2. The various alloys tested demonstrated significantly different bond strengths. 3. Differential statistical tests suggested that nonprecious alloys performed better with Ceramco porcelain than with Vita porcelain. 4. The bond strength of Ceramco porcelain fused to nonprecious alloy N-C2 was significantly greater than that of Ceramic and traditional gold-based alloys. 5. Nonprecious alloy N-C1 produced significantly less bond strength than the traditional gold-based alloys. 6. Semiprecious alloy W produced high bond strengths with both Ceramco and Vita porcelains. 7. The cylindrical pull-through test was a reliable, reproducible method of testing ceramic-metal bond shear strength. 8. The surface roughness appears to be the one common factor in nonprecious alloys that relates to large differences in bond strength. Additional tests must be made to verify this hypothesis.