In Vitro Assessment of Mineral Trioxide Aggregate Setting in the Presence of Interstitial Fluid Alone

Surface microhardness of three thicknesses of mineral trioxide aggregate in different setting conditions

“…However, the microhardness of 4 and 6 mm-thick MTA samples that received no additional moisture was significantly lower than that of samples with similar thickness but exposed to cotton pellets moistened with distilled water or PBS. In contrast to our results, DeAngelis et al showed no difference between the surface microhardness of 4 mm-thick MTA samples with or without a moist cotton pellet on the material in unvarnished roots 12. Budig and Eleazer also showed that ProRoot MTA powder packed within the roots could achieve a complete set because of the moisture absorbed through the roots submerged in saline for 72 hours 11.…”

“…Budig and Eleazer also showed that ProRoot MTA powder packed within the roots could achieve a complete set because of the moisture absorbed through the roots submerged in saline for 72 hours 11. These controversial results might be attributed to the absorption of moisture needed for the hydration of MTA from the intrinsic moisture retained within the dentinal tubules without the need of a wet cotton pellet 12,30. Although many studies have confirmed that the interaction between MTA and phosphate-containing solutions results in the formation of apatite crystalline structures over MTA, this study showed no difference between the microhardness of MTA samples having different thicknesses and exposed to PBS, which was comparable to that of the samples exposed to distilled water 16,17,31.…”

“…On the other hand, it has been reported that dry ProRoot MTA powder packed into the root canals could achieve a full set at 72 hours solely because of the moisture absorbed through the root without any extra moisture received from the coronal aspect of the MTA 11. The findings of recent investigations have also indicated that placing a moist cotton pellet on the MTA may be unnecessary to improve the setting of MTA 12,13,14…”

The effect of working time on the displacement of Biodentine™ beneath prefabricated stainless steel crown: a laboratory study

“…However, single visit treatments to perform pulp capping, pulpotomy and perforation repair procedures were recommended using glass‐ionomer cement (GIC) and zinc‐oxide eugenol cement placed over unset MTA . It was also found that the surface microhardness values of the MTA, with and without a moist cotton pellet, were not statistically different and the latter may not be essential for MTA setting in apexification procedures or situations in which the tissue surface of the MTA is against a moist opening of >1 mm . The contact of GIC with partially set MTA did not affect the setting time of GIC, the surface microhardness of MTA, and the shear bond strength between the two cements, thus it was suggested to place GIC over unset MTA in a single visit to avoid the need for multiple visits .…”

Cytotoxic effects of new MTA-based cement formulations on fibroblast-like MDPL-20 cells

“…19 Several changes in the surface composition and the morphology of MTA cement can lead to variations in its biological response and may result in clinically relevant differences. 20 The conflicting results observed in this in vitro study for the different cements could be also related to the emulsion added, which probably modified the chemical properties of the materials. 12,13 With this References in mind, the chemical changes made in the cement composition were designed to yield dental materials with good handling characteristic and adequate working time, associated with low cytotoxicity.…”