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Updated: Mar 20, 2026

Accessing the Cytotoxicity and Cell Response to Biomaterials
Published on: July 8, 2021
Effect of pH on physical properties of two endodontic biomaterials
Pooneh Mohebbi1, Saeed Asgary2
1Department of Endodontics, Dental Branch, Islamic Azad University, Tehran, Iran; Dental Research Center, Research Institute of Dental Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Aims:
To compare the surface microhardness, setting time, and elemental and topographic changes of mineral trioxide aggregate (MTA) and calcium-enriched mixture (CEM) in contact with acidic, neutral, and alkaline solutions.
Subjects And Methods:
For evaluating 24-h and 28-day surface microhardness using Vickers test and initial setting time using Gillmore apparatus, glass molds were filled manually or ultrasonically, either with CEM or MTA and randomly immersed in solutions with acidic, neutral, and alkaline pH (5.4, 7.4, and 9.4, respectively). Topographic changes of the samples as well as energy dispersive X-ray spectra were examined using the scanning electron microscopy.
Statistical Analysis Used:
Data were analyzed using the Kruskal-Wallis, Mann-Whitney, Wilcoxon, one- and two-way ANOVA, Tukey's post hoc, and t-tests.
Results:
After 28 days, there was an increase in the microhardness for all samples (without statistical significance [P > 0.05]), except for the samples of CEM in acidic environment (P > 0.05). The setting time of MTA samples was statistically higher than CEM samples (P ≤ 0.001). The setting time of both biomaterials was significantly higher in acidic pH than other groups (P ≤ 0.005). Surface topography and elemental constituents of biomaterials were altered in different solutions.
Conclusion:
The surface microhardness, setting time, and elemental and topographic properties of MTA and CEM were affected by different solutions. CEM exhibited quicker setting time than MTA; however, acidic solution negatively influenced both of them.

