Does adding accelerators to Mineral Trioxide Aggregate affect the shear bond strength?

Abstract

Background: It was aimed to evaluate the shear bond strength (SBS) of Mineral Trioxide Aggregate (MTA) with different accelerators to the composite resin at different setting times. Methods: One hundred-twenty acrylic blocks with central cavities were divided into 4 groups. Group 1 (control); only MTA, groups 2, 3 and 4 contain MTA mixed with 10% calcium chloride (CaCl2), 23.1% calcium lactate gluconate (CLG) and 15% disodium hydrogen phosphate (Na2HPO4), respectively. Each group was divided into 3 subgroups according to the setting time of 2 hours 45 minutes, 24 hours and 96 hours. After the adhesive system (Clearfil SE Bond, Kuraray) and composite resin (Clearfil Majesty, Kuraray) processes were completed, SBS test was applied on a universal testing machine. Data were analyzed using one-way ANOVA and Post Hoc Tukey tests (p<0.05). Results: MTA group (without accelerator) had the highest SBS values. When MTA (without accelerator) group was compared with groups of CLG and Na2HPO4 added to MTA as accelerators, the differences between them were significant (p<0.0001). There were no statistically significant differences between the subgroups in the initial setting time (p>0.05), the differences were significant in the other setting times (p<0.05). The addition of CLG and Na2HPO4 as accelerators to MTA decreased the SBS values at all setting times, while the addition of CaCl2 significantly increased the SBS value after 96 hours. Conclusion: Adding accelerators to MTA reduces the SBS values. However, adding 10% CaCl2 to MTA as an accelerator may reveal positive bonding results in restorative procedures after 96 hours.