Bond strength of prosthetic composite to primed and silicoated cast titanium

Purpose: The aim of this study was to examine the hypothesis that the bond strength of a polymer-glass composite to cast commercially pure titanium (CPTi) can be improved by treating the metal surface with adhesive metal primers or with heat-processed silicoating. Materials and Methods: Cast commercially pure titanium disks were prepared and the cast surfaces were air-abraded with 250 μm alumina. There was one control group and four test groups having forty specimens. A second group of forty specimens was similarly prepared, and subjected to a thermal cycling regimen. Three metal adhesive primers (Cesead II Opaque Primer, Metal Primer II, and Solidex) or silicoating (Siloc system) were applied to treated titanium surfaces. Two layers of polymer glass composite (Artglass) opaque and 1-mm thick increments each of dentin and enamel composite components were applied and separately lightpolymerized following manufacturer’s directions. All specimens were stored in 37oC water for 24 hours. Half of the specimens were thermal cycled in water (4 and 60oC) for 20,000 cycles. Shear bond strength for both groups was measured using a universal testing machine at a crosshead speed of 0.5mm/minute. Results (n=8) were statistically analyzed using ANOVA/Duncan’s test (α=0.05). Results: Specimens treated with the Cesead II Opaque Primer showed significantly higher (p<0.05) shear bond strength both with and without to thermal cycling with no significant decrease in values. The other metal primers and silicoating exhibited lower shear bond strengths with and without thermal cycling. Conclusion: The Cesead II Opaque Primer improved the bond strength and durability of Artglass to cast pure titanium metal discs. (Int Chin J Dent 2005; 5: 12-16.)