Methods: 80 human teeth with a flat surface of dentin were embedded in blocks of resin. 80 cylinders of RMGI (Fuji LCII® (GC)) were bonded on 80 teeth according various modalities: 10 on no-treated dentin, 10 after polyacrylic acid treatment, 10 after application of SEA (IBond® self-etch (Heraeus)), 10 after water contamination followed by an application of SEA, 10 after saliva contamination followed by an application of SEA, 10 after application of SEA followed by water contamination and 10 after application of SEA followed by saliva contamination. The dSBS was determined in a universal testing machine and the type of bond failure (mixte/adhesive/cohesive) was noted. A Kruskal-Wallis test was performed followed by Games-Howell post-hoc pairwise comparison tests on the dSBS results (p<0.05). A chi-square test was used for the analysis of bond failure (p < 0.05).
Results: Polyacrylic acid improved the bond strength (8±2 MPa) and SEA too (15±2 MPa), even in the case of water (before SEA 16±2 MPa or after SEA 21±4 MPa) or saliva contamination (before SEA 20±7 MPa or after SEA 19±6 MPa). No significant differences in debond locations were found between the various groups tested except for RMGI without dentin treatment, with 100% of adhesive failures.
Conclusions: The combination of SEA+RMGI triples the dSBS of RMGI. SEA+RMGI seems to tolerate water and saliva contaminations.