effect of different adhesive systems and silane application on shear bond strength of resin cement to indirect restorations

Objective: this study compared the influence of various adhesive systems and silane application on the adhesion of resin-based luting cement to lithium disilicate, indirect composite resin, and zirconia restorations. methods: lithium disilicate (n=50), indirect composite resin (n=50), and zirconia (n=50) blocks were divided into five groups (n=10), according to the adhesive protocol applied as follows: 1. optibond xtr, 2. silane + optibond all in one, 3. one coat 7 universal, 4) adper scotchbond multi-purpose, and 5) silane + single bond universal. the blocks were bonded to a resin-based luting cement after surface treatments (silica coating and acid application). the bonded specimens were incubated in 37° c water for 24 hours and thermocycled for 5,000 cycles. the shear bond strength (sbs) was evaluated by a universal testing machine. the adhesion protocols for each type of restoration were compared by one-way anova and dunnett t3 test. results: there were significant differences in the bond strength of cement to indirect restorations between various adhesive protocols (p<0.05). in all types of restorations, the highest sbs was observed in group 5, which was silanized and bonded with single bond universal. the bond strength of group 5 in lithium disilicate, indirect composite resin, and zirconia groups were 26.1 ± 4.9 mpa, 20.5 ± 5.7 mpa, and 15.4 ± 4.7 mpa, respectively. conclusions: it appears that the best adhesive protocol for bonding cement to lithium disilicate, indirect composite resin, and zirconia restorations is the use of silane and a universal adhesive containing silane (single bond universal).