Effect of acid etching on the micro-shear bond strength of resin composite-calcium silicate interface evaluated over different time intervals of bond aging.

Introduction: With the introduction of calcium silicate materials, pulp capping procedure has been simplified due to their therapeutic pulp capping capabilities and ability to be used as a provisional bulk restorative material simultaneously. The quality of the adhesive bond between these cements and composite is of clinical significance with regard to the longevity of the final laminate restoration. Thus, this study aims to compare the in vitro microtensile bond strengths of resin composite to different calcium silicate cements versus glass ionomer cement (GIC).

Materials and Methodology: Resin composite was bonded to standardized disks of Biodentine, mineral trioxide aggregate (MTA), and GIC. The samples were divided into the following three groups, and each group was further divided into two subgroups based on the aging time (1 and 2 weeks) of the samples: (1) Group 1 - phosphoric acid etching on Biodentine. (2) Group 2 - phosphoric acid etching on MTA. (3) Group 3 - phosphoric acid etching on GIC. After bond aging, the microtensile bond strength was analyzed using the Instron universal testing machine.

Results: There was no significant difference in micro-SBS between 1- and 4-week bond aging of MTA and Biodentine group, while a significant decrease is seen in the GIC group.

Conclusion: Calcium silicate cements are weak in the early setting phase. Thus, placing the overlying composite is best delayed for at least 2 weeks to allow adequate maturation of the material.