Abstract: The purpose of this study was to evaluate the shear bond strength of two self-adhesive cements with different polymerization modes. cemented to a Hybrid-Ceramic CAD/CAM blocks (VITA ENAMIC® for CEREC®/ inLab®, VITA Zahnfabrik H. Rauter GmbH & Co.KG., Germany),
Methods: Two self-adhesive resin cements: Rely X U200 (RX, 3M ESPE,St. Paul, MN, USA) and G-CEM Link ACE (GC, GC corporation, Tokyo, Japan). RX and GC groups with different polymerization modes (photo-curing (P) and self-curing (S)), were used in this study on hyprid ceramic Vita Enamic CAD/CAM blocks. Shear bond strength (SBS) tests were performed on all the specimens.
Results: The highest SBS was recorded with RX S group whilst the lowest SBS values were recorded with the GC S groups. Based on Tukey's post hoc significance analysis test, significance differences were observed between the RX S group compared to the GC S group (p < 0.05). No significance differences were found between data obtained from different curing modes of neither, RX S and RX P nor GC S and GC P. Adhesive pattern of failure was predominantly for most of the groups except RX S that was presented as predominant cohesive form of failure with the CAD/CAM hybrid ceramic block.
Conclusion: Within the limitations of this in vitro study, polymerization modes had no significance, but more mixed failure patterns were observed when using the photo-curing mode than when using the self-curing mode.