Effect of thermocycling on the micro-shear bond strength of solvent free and solvent containing self-etch adhesives to dentin

The aim was to investigate the effect of thermocycling on the microshear bond strength of one solvent free self etch adhesive system, Bond-1SF, and two solvent containing self-etch adhesives, Futurabond DC and Adper Easy One.Materials and methodsSixty caries free third molars were used to prepare specimens of dentin surfaces. The adhesives were applied on dentin surfaces according to the manufacturer's instructions then Grandio-SO Composite resin was condensed through a polyethylene tube with a one mm internal diameter and height attached firmly to dentin surfaces and light cured. The bonded specimens were stored in distilled water at 37 °C for 24 h before being tested. Half of the bonded specimens were tested for microshear bond strength without thermocycling and the other half were thermocycled in water baths held at 5°c and 55°c with a dwell time of 1 min each for 500 cycles prior to testing. The micro shears bond strength before and after thermocycling was calculated and statistically analyzed to show the interaction between different materials.ResultsWithout thermocycling, the bond strength of Futurabond DC and Adper Easy, were 22.524 MPa and 23.397 MPa respectively, while Bond-1 SF solvent free one step at lowered mean value 22.284 MPa and the difference was not statistically significant (p > 0.05). After thermocycling the bond strength of Futurabond DC and Adper Easy were 14.904 MPa, 22.713 MPa respectively, while Bond-1 SF solvent free one step self etch adhesive had 18.318 MPa and the differences were statistically significant (p > 0.05).ConclusionThermocycling had a negative effect on the bonding of self etching adhesive systems to dentin and solvent free adhesive system has non-significant lower bond strength in relation to solvent containing adhesive systems.