Shear Bond Strength and SEM/EDX of Two Bioactive Bulk Fill Resin Base Composite Restorations

Objective: To compare the shear bond strength of two bioactive bulk-fill dental restorative materials to sound dentin after aging in artificial saliva and to evaluate the mode of failure and elemental analysis by SEM/EDX. Material and Methods: Forty maxillary premolars extracted due to orthodontic reasons from subjects with ages between 14 and 30 years were used in this study. The teeth were divided into two groups according to the type of composite, Predicta Bioactive or Cention Forte. Each group had samples stored or not stored in artificial saliva. Occlusal dentin of all teeth was exposed by cutting 2mm below the deepest point on the occlusal surface of each tooth's crown. Each restorative material was applied according to the corresponding manufacture instructions. The shear bond strength was measured between the composite and dentin and by using SEM-EDX to evaluate the mode of failure and element analysis. Results: The study revealed that Cention Forte, after storage, exhibited the highest shear bond strength (10.13 MPa), followed by its non-stored samples (8.38 MPa), while Predicta Bioactive showed the lowest values, especially in the non-stored samples (6.38 MPa). Conclusion: Cention Forte had stronger bonding than Predicta Bioactive.