The effect of a novel silane blend system on resin bond strength to silica-coated Ti substrate

OBJECTIVES: The adhesive performance of 3-acryloyloxypropyltrimethoxysilane and a silane blend consisting of 3-acryloyloxypropyltrimethoxysilane and 1,2-bis(triethoxysilyl)ethane, adhering an experimental dendrimer-based resin to a silica-coated titanium surface, conditioned by CoJet method, was evaluated in vitro. METHODS: 3-Acryloyloxypropyltrimethoxysilane (1.0 vol%) and a blend of 3-acryloyloxy-propyltrimethoxysilane and 1,2-bis(triethoxysilyl)ethane (both 1.0 vol%) were prepared in acidified 95 vol% ethanol. A commercial 3-methcryloyloxypropyltrimethoxysilane (ESPE Si) was used as control. The silanes were applied onto tribochemically silica-coated titanium surfaces. Fresh silane solution hydrolysis (activation) was monitored by Fourier transform infrared (FTIR) spectrometry. Experimental dendrimer resin stubs were applied and photo-polymerized on titanium. The specimens were thermocycled (6000 cycles, 5-55 degrees C). Before measuring shear bond strength of the resin to titanium, surface imaging was carried out with a scanning electron microscope (SEM) with elemental analysis applying energy dispersive X-ray analysis (EDXA). RESULTS: Statistical analysis (ANOVA) showed that the highest shear bond was obtained with 1.0 vol% 3-acryloyloxypropyltrimethoxysilane+1.0 vol% 1,2-bis(triethoxysilyl)ethane blend (5.2+/-1.3 MPa), and the lowest result with fresh commercial 3-methacryloyloxypropyltrimethoxysilane, ESPE Sil (2.1+/-0.8 MPa). 3-Acryloyloxypropyltrimethoxysilane yielded 4.1+/-1.0 MPa. The type of silane affected significantly the shear bond strength (ANOVA, p<0.001). All silanes were activated according to the infrared spectra. The SEM/EDXA analysis revealed an uneven distribution of titanium, silicon, and aluminum on silica-coated Ti surfaces. CONCLUSION: Silanization with 3-acryloyloxypropyltrimethoxysilane might offer better bonding of a novel dendrimer resin to silica-coated titanium than using a pre-hydrolyzed 3-methacryloyloxypropyltrimethoxysilane.