Dentin Bonding of TheraCal LC Calcium Silicate Containing an Acidic Monomer: An In Vitro Study

The purpose of this study was to evaluate whether the incorporation of an acidic monomer into the pulp-capping material TheraCal LC, which has a weak dentin bonding, increases the shear bond strength (SBS) to dentin. Di-2-hydroxyethyl methacryl hydrogenphosphate was incorporated into the material at 0.0 (TL0, control), 5.0 (TL5), and 10.0 (TL10) wt%. The water contact angle (CA) and mechanical properties for each material were also studied (n = 6). Debonding was performed at two different times (immediate and after 24 h) (n = 12). Hydroxyl and calcium ion releases in water at 37 °C were monitored up to 28 days (n = 6). The addition of the acidic monomer decreased the CAs (p < 0.001) and increased the flexural moduli (p < 0.001). The debonding time did not significantly affect the SBS values (p = 0.600). The TL10 group exhibited the highest SBS values, followed by the TL5 group. The TL10 group released significantly more calcium ions than the other two groups from 3 days (p < 0.05). The incorporation of the acidic monomer at 10.0 wt% into TheraCal LC enhanced bonding to dentin, while not negatively affecting the mechanical properties and ion-leaching capacity of the material.