Comparative analysis of shear bond strength of MTA and Theracal PT with different restorative materials

This study aimed to compare the in vitro shear bond strength (SBS) of mineral trioxide aggregate (MTA) and dual-cured, resin-modified calcium silicate material (Theracal PT) to composite resin, compomer, and bulk-fill composite, and to evaluate the bond failure mode under a stereomicroscope.

Ninety acrylic specimens, each with a 4 mm diameter and 2 mm height central hole, were prepared. These specimens were randomly divided into two groups based on the capping materials: MTA and Theracal PT. Each group was further subdivided into three subgroups (n = 15) according to the restorative materials: composite resin, compomer, and bulk-fill composite. The specimens were then subjected to shear testing using a universal testing machine at a crosshead speed of 1 mm/min. Post-test, the fracture locations were examined using a stereomicroscope. Data were analyzed using a two-way analysis of variance (ANOVA) and the Tukey test.

The SBS values for the Theracal PT group were significantly higher than those for the MTA group (p < 0.001). Within the MTA groups, no significant differences were observed in SBS values across the different restorative materials. However, a significant difference was found between the mean SBS values of the Theracal PT + composite resin group and the Theracal PT + compomer group (p < 0.001).

Theracal PT shows promise in dentistry due to its superior bond strength. Given its bond values, Theracal PT appears capable of forming durable and long-lasting restorations by establishing reliable bonds with various restorative materials commonly used in dentistry.