Bonding promotion of resin composite to silica-coated zirconia implant surface using a novel silane system

Bonding of restorative materials in dentistry may be enhanced significantly by the use of engineered silane blends. Trialkoxy silane esters have the unique property to unite dissimilar materials. Silanization is required when cementing the crown or the abutment on a silica-coated zirconia subgingival implant surface with an organophosphate-resin-composite. In this laboratory study, we report about our latest findings in laboratory experiments on experimental silane primers.

In the adhesion promotion of resin-composites to the zirconia implant surface using four experimental blends, a so-called "Novel Silane System", consisting of a functional silane (3-acryloxypropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane and 3-styrylethyltrimethoxysilane) and a cross-linking silane, bis-1,2-(triethoxysilyl)ethane, were mixed in a water/ethanol solvent system with a pH of 4.5, and applied onto silica-coated planar zirconia specimens. A resin composite stub (with a bonding area diameter of 2.0 mm) was cemented using a polypropylene mold. Initial shear bond strengths (baseline values) were measured of specimens after dry storage and after thermo-cycling between 5.0 ± 0.5°C and 55.0 ± 0.5°C. As the control was a dental prehydrolyzed ready-to-use silane product.

All the values for shear bond strength test were significantly increased (P > 0.05) during thermo-cycling. The results showed that the highest shear bond strength was obtained for 3-glycidoxypropyltrimethoxysilane +bis-1,2-(triethoxysilyl)ethane in both dry and thermo-cycled conditions with stress values of 11.04 and 14.89 MPa, respectively. The lowest values were found for the control silane in both dry and thermo-cycled conditions with stress values of 4.5 and 6.5 MPa, respectively.

Silanization with a novel silane system yielded significantly higher shear bond strength than the control silane (a 3-methacryloxypropyltrimethoxysilane containing). We have introduced a bonding system that might be useful and durable in implant dentistry.