Abstract

Aim: Assessment of the push-out bond strength of four MTA-based formulations for use as root-end filling materials. Methodology: MTA Plus mixed with (i) water (‘MTA-W’); (ii) a proprietary water-based antiwashout gel (‘MTA-AW’); (iii) Superbond C&B chemically curing resin (‘MTA-Chem’); and (iv) Heliobond lightcuring resin (‘MTA-Light’) was tested. Root slices 3 mm thick human had a 1.5 mm diameter hole drilled centrally and were treated with 17% EDTA for 60s. Forty specimens divided into groups 1–4 were prepared and filled with MTA-W, MTA-AW, MTAChem and MTA-Light, respectively. Groups 3 and 4 were etched with 37% phosphoric acid for 60s, and bonding agent was applied to the dentine surface. Specimens were stored for 28 days in Hanks’ Balanced Salt Solution at 37 °C. Push-out strength was tested with a punch and die (punch diameter 1.3 mm, die diameter 2.0 mm, punch speed 1 mm min 1). Stereomicroscopy was used to classify failure mode (adhesive, cohesive or mixed type). Results: The resulting push-out strengths were 5.1 MPa (MTA-W), 4.3 MPa (MTA-AW), 4.7 MPa (MTAChem) and 11.0 MPa (MTA-Light). MTA-W had higher push-out strength than MTA-AW (P = 0.022). The same was noted for MTA-Light relative to the other materials (P < 0.05). All materials exhibited adequate push-out strengths compared with MTA-W. Failure was predominantly mixed, except for MTAChem (predominantly adhesive). Conclusions: All materials exhibited adequate push-out strength. Previous studies have shown the new formulations have additional advantages including increased washout resistance and faster setting time, making them promising for future dental applications.  (International Endodontic Journal, 47, 454–462, 2014. )