Shear bond strength of Bis-GMA resin and methacrylated dendrimer resins on silanized titanium substrate

The study compared the bond strengths of three resins, Bis-GMA and two novel experimental methacrylated polyester dendrimer resins to grit-blasted titanium substrate with three silanes.

Two commercial dental silanes (ESPE Sil and Monobond-S) and an experimental 0.5 vol% 3-methacryloxypropyltrimethoxysilane were applied to grit-blasted Ti substrates. Light-polymerizable resins of Bis-GMA and methacrylated dendrimer were applied to the grit-blasted Ti substrate with polyethylene molds. The substrates with resin stubs (n = 10) were thermocycled (6000 cycles, 5-55 degrees C) or kept in water (37 degrees C, 24 h). The shear bond strength of the resin was measured at a crosshead speed of 1.0 mm min(-1). The surface examination, before and after silanization, was made with a scanning electron microscope (SEM). The silane reactions on the Ti surface were monitored by Fourier transform infrared spectrometry.

Statistical analysis (ANOVA) showed that the highest shear bond for thermocycled samples was obtained for Bis-GMA with Monobond-S (19.4 MPa, standard deviation (SD) 7.1 MPa), and after water storage with a laboratory-made silane (26.4 MPa, SD 8.1 MPa). The dendrimer and Bis-GMA resins conferred equal bonding properties to grit-blasted titanium after thermocycling. The silane, resin type, and storage conditions significantly affected the shear bond strength (p < 0.001 for all factors). SEM images suggested a mainly cohesive type of bonding failure.

A dendrimer based resin and the Bis-GMA resin systems conferred statistically equivalent bonding properties to silica-coated Ti after thermocycling.