Bond strength of prosthetic composite to primed and silicoated cast titanium

Kenneth S. Kurtz, DDS,(a) Ikuya Watanabe, DDS, PhD,(b) Chikahiro Ohkubo, DMD, PhD,(c) and David Silken, DDS(d)

(a)International Program in Prosthodontics, New York University College of Dentistry, New York, NY, USA, (b)Department of Biomaterials Science, Baylor College of Dentistry, Texas A&M University System Health Science Center, Dallas, TX, USA, (c)Department of Removable Prosthodontics, Tsurumi University School of Dental Medicine, Yokohama, Japan, and (d)New York Hospital Queens, Fresh Meadows, NY, USA

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 light- polymerized following manufacturerユs directions. All specimens were stored in 37℃ water for 24 hours. Half of the specimens were thermal cycled in water (4 and 60℃) 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.)
Clinical Significance: In vitro application of the MDP phosphate primer (Cesead II Opaque) demonstrated the highest shear bond strength of a light-polymerized laboratory composite material (Artglass) to cast CP titanium and strength values seemed to be unaffected by thermal cycling. For cast CP titanium prostheses, this type of metal primer may improve the durability of the bonded composite veneer-metal interface and may enhance the esthetic longevity of the fabricated prosthesis.
Key Words: bond strength, cast titanium, metal primer, resin composite, silicoating.