ElectroBond Improves Immediate Dentin Microtensile Bond Strength of Two Etch-and-Rinse Adhesives

Purpose: The aim of this study was to investigate whether an electrical device for dental adhesive application (ElectroBond) influences bonding of two-step etch-and-rinse adhesives. Materials and Methods: Human teeth were selected and cut perpendicularly to their long axis to expose middle/deep dentin. Specimens were then longitudinally sectioned into halves (experimental and control halves) to create two similar bonding substrates. Experimental halves were bonded using an ElectroBond-assisted application, while control halves were bonded with disposable sponges. The adhesives tested were Adper Scotchbond 1XT and XP-BOND. Bonded specimens were submitted to the microtensile bond strength test. Additional adhesive interfaces were prepared and processed for nanoleakage investigation involving TEM examination. Results: The microtensile bond test revealed higher values (p < 0.05) for both adhesives if ElectroBond was used during layering (55.5 +/- 7.9 IVIPa for Adper Scotchbond 1XT and 54.7 +/- 7.1 IVIPa for XP-BOND) compared to the conventional mechanical adhesive application technique (41.1 +/- 6.1 MPa for Adper Scotchbond 1XT and 38.0 +/- 7.8 MPa for XP-BOND). No difference between the two adhesives was found under the same application conditions. With electricity-assisted application, TEM micrographs revealed a significant decrease in nanoleakage expression compared to the controls. Conclusion: The use of an electric current produced by ElectroBond during the application of two-step etch-and-rinse adhesives may enhance resin impregnation, thus improving dentin hybridization. Further studies should be done to confirm that this device can similarly improve adhesive application in vivo.