Technique sensitivity in bonding to vital, acid-etched dentin

Just as vital dentin is moist after removing the smear layer, avoiding collapse of the collagen matrix after acid-etching requires in vivo validation. This study hypothesizes that there is no difference between moist bonding performed in vitro or in vivo, and that excessive drying or wetting of vital acid-etched dentin produces inferior results. Resin-dentin interfaces bonded with a moist bonding technique (control), either in vitro or in vivo with Excite DSC (Vivadent), were examined with and without tracer penetration using transmission electron microscopy. Specimens bonded in vivo under excessively dry and wet conditions were also examined. The patterns of silver deposition were similar within the adhesive and hybrid layers created in vitro or in vivo. No hybrid layer was observed in vivo after excessive drying. Excessive wetting in vivo resulted in more extensive nanoleakage and water tree formation along resin-dentin interfaces.