Aim To analyse the influence of exposure of mineral trioxide aggregate (MTA) with and without calcium chloride (CaCl2) to phosphate‐buffered saline (PBS) on the push‐out bond strength, over different experimental periods. Methodology One hundred and twenty dentine discs with standardized cavities were filled with MTA with and without 10% CaCl2. The specimens were randomly divided as follows (n = 30): (G1) MTA in contact with a moistened cotton pellet, (G2) MTA immersed in PBS, (G3) MTA + CaCl2 in contact with a moistened cotton pellet and (G4) MTA + CaCl2 immersed in PBS. The samples were stored for 3, 28 and 60 days. The bond strengths were measured with the Instron Testing machine. Data were analysed using the three‐way anova and Tukey test (P < 0.05). Results In general, the samples of MTA with and without CaCl2, exposed to PBS, had higher bond strength values in all study periods (P < 0.05). Analysis of the influence of addition of CaCl2 to MTA (G1 × G3) evidenced significant differences in bond strength in the different periods (P < 0.05). Conclusions The exposure of MTA to PBS positively influenced the push‐out bond strength, whereas the addition of CaCl2 had a negative influence.