Effect of Propylene Glycol on the Bond Strength of Two Endodontic Cements

This study evaluated the effect of propylene glycol (PG) on the push-out bond strength of calcium-enriched mixture (CEM) cement compared to mineral trioxide aggregate (MTA). Methods and Materials: The lumens of two hundred 2±0.2 mm-thick root sections from human extracted teeth were prepared to achieve a diameter of 1.3 mm. The samples were then allocated into eight groups of 25 on the basis of the materials used (MTA or CEM cement) and different proportions of PG (0%, 20%, 505, and 100%). In each group, 0.4 mL of the liquid was mixed with 1 g MTA or CEM cement. After incubation, the push-out strength of the samples was measured using a universal testing machine. Data were analyzed using the two-way ANOVA followed by one-way ANOVA and student’s t-test. The MTA group showed significantly higher bond strength in comparison with CEM group (P≤0.001). Also 100% and 20% PG increased the bond strength of MTA (P≤0.001). For CEM cement, 100% and 50% PG decreased the bond strength (P≤0.001). This in vitro study demonstrated that while PG increased the push-out bond strength of MTA, it is not recommended for mixing with CEM cement.