Effect of sandblasting and silicoating on bond strength of polymer-glass composite to cast titanium

Abstract

Statement of problem. There is little information regarding the mechanical and chemical retention of polymer-glass composite to cast titanium. Purpose. This study examined whether sandblasting in conjunction with silicoating improves the bond strength of the polymer-glass composite to cast titanium. Materials and methods. Disk patterns (10 mm in diameter, 2.5 mm thick) were cast with commercially pure titanium (CP Ti) and Type IV gold alloy. Three pretreatments were applied: 50 μm Al 2O 3 sandblasting (50 SB), 250 μm Al 2O 3 sandblasting (250 SB), and 600-grit SiC paper polishing (600 SiC). After surface preparation, the Siloc system (silicoating) was applied on the disks. The 50 SB specimens without Siloc system were also prepared as controls. Then sticky tape with a circular hole (4.76 mm diameter) was placed onto the disk to define the bonding area. Artglass (polymer-glass) opaque, dentin, and enamel composites were applied using Teflon matrices and then light-polymerized. Shear bond strength (n = 8) was determined at a crosshead speed of 5 mm/min. Results were analyzed statistically with 2-way ANOVA and the Tukey-Kramer test (α=.05). Results. The Siloc system significantly ( P <.05) improved the mean shear bond strength of Artglass to both metals in the 50 SB specimens. Statistical differences ( P <.05) in shear bond strength were found among surface treatments for the silicoated CP Ti specimens, in which 250 SB specimens yielded the greatest bond strength. The Type IV specimens treated with Siloc system showed no significant differences in shear bond strength between the 50 SB and the 250 SB specimens. Conclusion. Sandblasting with coarser alumina particles in conjunction with silicoating significantly enhanced bond strength of polymer-glass composite to cast titanium. (J Prosthet Dent 1999;82:462-7.)