The Shear Bond Strength Between Calcium Silicate-Based Biomaterials and Glass Ionomer Restorative Materials: An In Vitro Comparative Study

Aim: The aim of this study was to comparatively evaluate the shear bond strengths between different calcium silicate-based biomaterials and glass ionomer-based restorative materials. Materials and Methods: In this in vitro study, a total of 96 acrylic blocks were prepared, each containing a standardized cylindrical cavity measuring 4 mm in diameter and 2 mm in depth. Four different calcium silicate-based biomaterials (ProRoot MTA, Biodentine, TheraCal LC, and MTA BioRep) were placed into the cavities according to the manufacturers’ instructions. Three different glass ionomer restorative materials (Fuji II LC, Equia Forte HT, and Riva Self Cure) were then applied onto the biomaterial surfaces using molds measuring 2 mm in diameter and 2 mm in height, resulting in 12 experimental groups (n = 8). After storage at 37 °C for 24 h, the shear bond strengths were measured using a universal testing machine. The data were analyzed using the Kruskal–Wallis and Mann–Whitney U tests with Bonferroni correction (p < 0.05). Results: The highest bond strength was observed in the TheraCal LC–Fuji II LC combination, whereas the lowest value was obtained in the MTA BioRep–Equia Forte HT group. Both the type of biomaterial and type of glass ionomer cement had a statistically significant effect on the bond strength (p < 0.05). Conclusions: The combination of calcium silicate-based biomaterial and glass ionomer-based restorative material influenced the early shear bond strength. These findings suggest that material selection may play an important role in early bonding behavior at the biomaterial–restorative material interface.