Comparative Evaluation of the Shear Bond Strength of Calcium Silicate-Based Pulp Capping Materials to Nano-Hybrid Composite Resins: An In-Vitro Study

Objectives: This study aimed to compare the shear bond strength (SBS) of different calcium silicate-based (CSB) pulp capping materials (Biodentine™ and TheraCal LC®) to two nano-hybrid composite resins.Materials and Methods: Biodentine™ and TheraCal LC® were applied to the central holes (4 mm × 2 mm) prepared in eighty acrylic blocks. Each group was randomly divided into two subgroups. Two nano-hybrid composites (Omnichroma and GC G-ænial) were applied over each different calcium silicate-based material using cylindrical polyethylene molds (2 mm × 2 mm) and light cured. Shear bond strength values were measured using a universal testing machine. Failure modes were examined under a stereomicroscope and classified as adhesive, cohesive, or mixed type. Data were analyzed using the Shapiro-Wilk and independent t-tests.Results: SBS values for Omnichroma after the use of TheraCal LC® and Biodentine™ were 9.33 ± 2.46 MPa and 3.42 ± 1.02 MPa, respectively. Likewise, SBS values for G-ænial after the use of both CSB materials were 8.37 ± 1.83 MPa and 3.62 ± 1.36 MPa, respectively. There was no statistically significant difference between the two composite resins for either of the different calcium silicate-based materials (p=0.176 and p=0.726, respectively). Additionally, in the use of both composites, TheraCal LC® showed higher SBS values than Biodentine™ (p=0.001 and p=0.001). The most frequently observed failure mode was the mixed type for all restoratives.Conclusion: TheraCal LC® demonstrated higher bond strength compared with Biodentine™, and this finding suggests that it may serve as a more advantageous option in restorative applications.