Abstract
The aim of this study was to investigate if air thinning of bonding resin would affect bond strength and marginal microleakage for enamel and dentin using three self-etching primer adhesive systems, Clearfil Mega Bond, UniFil Bond and Imperva Fluoro Bond. Tensile bond strengths to bovine enamel and dentin, and microleakage in the cervical cavities prepared on the extracted human molars were measured. For the enamel, there was no significant difference both in bond strength and microleakage between brush thinning and air thinning for any of the three adhesive systems. However, the bond strength to dentin with air thinning was significantly reduced compared to those obtaining with brush thinning for the three adhesive systems (p<0.01). For Clearfil Mega Bond and Imperva Fluoro Bond, the microleakage at the dentin with brush thinning was significantly smaller than those obtained with air thinning (p<0.05). For UniFil Bond, the leakage with brush thinning appeared to be smaller than those obtained with air thinning, despite of no significant difference. In conclusion, for adhesive systems using self-etching primers, thinning of the bonding resin by a brush achieved favorable bond performances compared to air thinning.
