Physical and Chemical Properties and Subcutaneous Implantation of Mineral Trioxide Aggregate Mixed with Propylene Glycol

• 20% PG + 80% DW was tested to improve MTA handling.
• It increased final setting time but reduced solubility and film thickness.
• The flowability increased with PG association but not significantly.
• The pH was significantly high for MTA mixed with PG in the final assessment.
• Inflammation degree was similar in both associations.

IntroductionThe aim of this study was to evaluate the physical, chemical, and biological properties of mineral trioxide aggregate (MTA) mixed with 80% distilled water and 20% propylene glycol (PG) compared with MTA mixed with distilled water only.MethodsFlowability, film thickness, and solubility were analyzed according to American National Standards Institute/American Dental Association specification 57/2000. Initial and final setting times were assessed according to American Society for Testing and Materials specification C266/08. Porosity was assessed by using mercury intrusion porosimetry after 1 and 28 days of hydration, and the pH and calcium ion release were assessed after 3, 24, 72, and 168 hours. For the tissue reaction, the cements were implanted in 24 albino rats (2 groups, n = 12). An analysis of the inflammatory infiltrate was performed after 15, 30, and 60 days.ResultsMTA + PG exhibited lower film thickness and higher final setting time. No differences were verified for flowability (P > .05). MTA + PG showed high porosity at 1 day of hydration (P < .05). All the test cements demonstrated an alkaline pH. Microscopic analysis of the specimens revealed neoformation of connective tissue in contact with the cements.ConclusionsThe introduction of PG as a mixing vehicle alters the physical and chemical properties of MTA and is biologically acceptable.