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 XPBOND. 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 MPa for Adper Scotchbond 1XT and 54.7 ± 7.1 MPa 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. Palabras clave: dentin bonding systems, electric current, TEM, microtensile, dentin